01YeBdWm

1#	WELCOME TO SQUID 3.4.8
2#	----------------------------
3#	
4#	This is the documentation for the Squid configuration file.
5#	This documentation can also be found online at:
6#		http://www.squid-cache.org/Doc/config/
7#	
8#	You may wish to look at the Squid home page and wiki for the
9#	FAQ and other documentation:
10#		http://www.squid-cache.org/
11#		http://wiki.squid-cache.org/SquidFaq
12#		http://wiki.squid-cache.org/ConfigExamples
13#	
14#	This documentation shows what the defaults for various directives
15#	happen to be.  If you don't need to change the default, you should
16#	leave the line out of your squid.conf in most cases.
17#	
18#	In some cases "none" refers to no default setting at all,
19#	while in other cases it refers to the value of the option
20#	- the comments for that keyword indicate if this is the case.
21#
22
23#  Configuration options can be included using the "include" directive.
24#  Include takes a list of files to include. Quoting and wildcards are
25#  supported.
26#
27#  For example,
28#
29#  include /path/to/included/file/squid.acl.config
30#
31#  Includes can be nested up to a hard-coded depth of 16 levels.
32#  This arbitrary restriction is to prevent recursive include references
33#  from causing Squid entering an infinite loop whilst trying to load
34#  configuration files.
35#
36#  Values with byte units
37#
38#	Squid accepts size units on some size related directives. All
39#	such directives are documented with a default value displaying
40#	a unit.
41#
42#	Units accepted by Squid are:
43#		bytes - byte
44#		KB - Kilobyte (1024 bytes)
45#		MB - Megabyte
46#		GB - Gigabyte
47#
48#  Values with spaces, quotes, and other special characters
49#
50#	Squid supports directive parameters with spaces, quotes, and other
51#	special characters. Surround such parameters with "double quotes". Use
52#	the configuration_includes_quoted_values directive to enable or
53#	disable that support.
54#
55#	For example;
56#
57#		configuration_includes_quoted_values on
58#		acl group external groupCheck Administrators "Internet Users" Guest
59#		configuration_includes_quoted_values off
60#
61#
62#  Conditional configuration
63#
64#	If-statements can be used to make configuration directives
65#	depend on conditions:
66#
67#	    if <CONDITION>
68#	        ... regular configuration directives ...
69#	    [else
70#	        ... regular configuration directives ...]
71#	    endif
72#
73#	The else part is optional. The keywords "if", "else", and "endif"
74#	must be typed on their own lines, as if they were regular
75#	configuration directives.
76#
77#	NOTE: An else-if condition is not supported.
78#
79#	These individual conditions types are supported:
80#
81#	    true
82#		Always evaluates to true.
83#	    false
84#		Always evaluates to false.
85#	    <integer> = <integer>
86#	        Equality comparison of two integer numbers.
87#
88#
89#  SMP-Related Macros
90#
91#	The following SMP-related preprocessor macros can be used.
92#
93#	${process_name} expands to the current Squid process "name"
94#	(e.g., squid1, squid2, or cache1).
95#
96#	${process_number} expands to the current Squid process
97#	identifier, which is an integer number (e.g., 1, 2, 3) unique
98#	across all Squid processes.
99
100#  TAG: broken_vary_encoding
101#	This option is not yet supported by Squid-3.
102#Default:
103# none
104
105#  TAG: cache_vary
106#	This option is not yet supported by Squid-3.
107#Default:
108# none
109
110#  TAG: collapsed_forwarding
111#	This option is not yet supported by Squid-3. see http://bugs.squid-cache.org/show_bug.cgi?id=3495
112#Default:
113# none
114
115#  TAG: error_map
116#	This option is not yet supported by Squid-3.
117#Default:
118# none
119
120#  TAG: external_refresh_check
121#	This option is not yet supported by Squid-3.
122#Default:
123# none
124
125#  TAG: location_rewrite_program
126#	This option is not yet supported by Squid-3.
127#Default:
128# none
129
130#  TAG: refresh_stale_hit
131#	This option is not yet supported by Squid-3.
132#Default:
133# none
134
135#  TAG: ignore_ims_on_miss
136#	Remove this line. The HTTP/1.1 feature is now configured by 'cache_miss_revalidate'.
137#Default:
138# none
139
140#  TAG: ignore_expect_100
141#	Remove this line. The HTTP/1.1 feature is now fully supported by default.
142#Default:
143# none
144
145#  TAG: dns_v4_fallback
146#	Remove this line. Squid performs a 'Happy Eyeballs' algorithm, the 'fallback' algorithm is no longer relevant.
147#Default:
148# none
149
150#  TAG: ftp_list_width
151#	Remove this line. Configure FTP page display using the CSS controls in errorpages.css instead.
152#Default:
153# none
154
155#  TAG: maximum_single_addr_tries
156#	Replaced by connect_retries. The behaviour has changed, please read the documentation before altering.
157#Default:
158# none
159
160#  TAG: update_headers
161#	Remove this line. The feature is supported by default in storage types where update is implemented.
162#Default:
163# none
164
165#  TAG: url_rewrite_concurrency
166#	Remove this line. Set the 'concurrency=' option of url_rewrite_children instead.
167#Default:
168# none
169
170#  TAG: dns_testnames
171#	Remove this line. DNS is no longer tested on startup.
172#Default:
173# none
174
175#  TAG: extension_methods
176#	Remove this line. All valid methods for HTTP are accepted by default.
177#Default:
178# none
179
180#  TAG: zero_buffers
181#Default:
182# none
183
184#  TAG: incoming_rate
185#Default:
186# none
187
188#  TAG: server_http11
189#	Remove this line. HTTP/1.1 is supported by default.
190#Default:
191# none
192
193#  TAG: upgrade_http0.9
194#	Remove this line. ICY/1.0 streaming protocol is supported by default.
195#Default:
196# none
197
198#  TAG: zph_local
199#	Alter these entries. Use the qos_flows directive instead.
200#Default:
201# none
202
203#  TAG: header_access
204#	Since squid-3.0 replace with request_header_access or reply_header_access
205#	depending on whether you wish to match client requests or server replies.
206#Default:
207# none
208
209#  TAG: httpd_accel_no_pmtu_disc
210#	Since squid-3.0 use the 'disable-pmtu-discovery' flag on http_port instead.
211#Default:
212# none
213
214#  TAG: wais_relay_host
215#	Replace this line with 'cache_peer' configuration.
216#Default:
217# none
218
219#  TAG: wais_relay_port
220#	Replace this line with 'cache_peer' configuration.
221#Default:
222# none
223
224# OPTIONS FOR AUTHENTICATION
225# -----------------------------------------------------------------------------
226
227#  TAG: auth_param
228#	This is used to define parameters for the various authentication
229#	schemes supported by Squid.
230#
231#	format: auth_param scheme parameter [setting]
232#
233#	The order in which authentication schemes are presented to the client is
234#	dependent on the order the scheme first appears in config file. IE
235#	has a bug (it's not RFC 2617 compliant) in that it will use the basic
236#	scheme if basic is the first entry presented, even if more secure
237#	schemes are presented. For now use the order in the recommended
238#	settings section below. If other browsers have difficulties (don't
239#	recognize the schemes offered even if you are using basic) either
240#	put basic first, or disable the other schemes (by commenting out their
241#	program entry).
242#
243#	Once an authentication scheme is fully configured, it can only be
244#	shutdown by shutting squid down and restarting. Changes can be made on
245#	the fly and activated with a reconfigure. I.E. You can change to a
246#	different helper, but not unconfigure the helper completely.
247#
248#	Please note that while this directive defines how Squid processes
249#	authentication it does not automatically activate authentication.
250#	To use authentication you must in addition make use of ACLs based
251#	on login name in http_access (proxy_auth, proxy_auth_regex or
252#	external with %LOGIN used in the format tag). The browser will be
253#	challenged for authentication on the first such acl encountered
254#	in http_access processing and will also be re-challenged for new
255#	login credentials if the request is being denied by a proxy_auth
256#	type acl.
257#
258#	WARNING: authentication can't be used in a transparently intercepting
259#	proxy as the client then thinks it is talking to an origin server and
260#	not the proxy. This is a limitation of bending the TCP/IP protocol to
261#	transparently intercepting port 80, not a limitation in Squid.
262#	Ports flagged 'transparent', 'intercept', or 'tproxy' have
263#	authentication disabled.
264#
265#	=== Parameters for the basic scheme follow. ===
266#
267#	"program" cmdline
268#	Specify the command for the external authenticator.  Such a program
269#	reads a line containing "username password" and	replies with one of
270#	three results:
271#
272#	  OK
273#		the user exists.
274#
275#	  ERR
276#		the user does not exist.
277#
278#	  BH
279#		An internal error occurred in the helper, preventing
280#		a result being identified.
281#
282#	"ERR" and "BH" results may optionally be followed by message="..."
283#	containing a description available as %m in the returned error page.
284#
285#	If you use an authenticator, make sure you have 1 acl of type
286#	proxy_auth.
287#
288#	By default, the basic authentication scheme is not used unless a
289#	program is specified.
290#
291#	If you want to use the traditional NCSA proxy authentication, set
292#	this line to something like
293#
294#	auth_param basic program /usr/lib/squid3/basic_ncsa_auth /usr/etc/passwd
295#
296#	"utf8" on|off
297#	HTTP uses iso-latin-1 as character set, while some authentication
298#	backends such as LDAP expects UTF-8. If this is set to on Squid will
299#	translate the HTTP iso-latin-1 charset to UTF-8 before sending the
300#	username & password to the helper.
301#
302#	"children" numberofchildren [startup=N] [idle=N] [concurrency=N]
303#	The maximum number of authenticator processes to spawn. If you start too few
304#	Squid will have to wait for them to process a backlog of credential
305#	verifications, slowing it down. When password verifications are
306#	done via a (slow) network you are likely to need lots of
307#	authenticator processes.
308#
309#	The startup= and idle= options permit some skew in the exact amount
310#	run. A minimum of startup=N will begin during startup and reconfigure.
311#	Squid will start more in groups of up to idle=N in an attempt to meet
312#	traffic needs and to keep idle=N free above those traffic needs up to
313#	the maximum.
314#
315#	The concurrency= option sets the number of concurrent requests the
316#	helper can process.  The default of 0 is used for helpers who only
317#	supports one request at a time. Setting this to a number greater than
318#	0 changes the protocol used to include a channel number first on the
319#	request/response line, allowing multiple requests to be sent to the
320#	same helper in parallel without waiting for the response.
321#	Must not be set unless it's known the helper supports this.
322#
323#	auth_param basic children 20 startup=0 idle=1
324#
325#	"realm" realmstring
326#	Specifies the realm name which is to be reported to the
327#	client for the basic proxy authentication scheme (part of
328#	the text the user will see when prompted their username and
329#	password). There is no default.
330#	auth_param basic realm Squid proxy-caching web server
331#
332#	"credentialsttl" timetolive
333#	Specifies how long squid assumes an externally validated
334#	username:password pair is valid for - in other words how
335#	often the helper program is called for that user. Set this
336#	low to force revalidation with short lived passwords.  Note
337#	setting this high does not impact your susceptibility
338#	to replay attacks unless you are using an one-time password
339#	system (such as SecureID).  If you are using such a system,
340#	you will be vulnerable to replay attacks unless you also
341#	use the max_user_ip ACL in an http_access rule.
342#
343#	"casesensitive" on|off
344#	Specifies if usernames are case sensitive. Most user databases are
345#	case insensitive allowing the same username to be spelled using both
346#	lower and upper case letters, but some are case sensitive. This
347#	makes a big difference for user_max_ip ACL processing and similar.
348#	auth_param basic casesensitive off
349#
350#	=== Parameters for the digest scheme follow ===
351#
352#	"program" cmdline
353#	Specify the command for the external authenticator.  Such
354#	a program reads a line containing "username":"realm" and
355#	replies with one of three results:
356#
357#	  OK ha1="..."
358#		the user exists. The ha1= key is mandatory and
359#		contains the appropriate H(A1) value, hex encoded.
360#		See rfc 2616 for the definition of H(A1).
361#
362#	  ERR
363#		the user does not exist.
364#
365#	  BH
366#		An internal error occurred in the helper, preventing
367#		a result being identified.
368#
369#	"ERR" and "BH" results may optionally be followed by message="..."
370#	containing a description available as %m in the returned error page.
371#
372#	By default, the digest authentication scheme is not used unless a
373#	program is specified.
374#
375#	If you want to use a digest authenticator, set this line to
376#	something like
377#
378#	auth_param digest program /usr/lib/squid3/digest_pw_auth /usr/etc/digpass
379#
380#	"utf8" on|off
381#	HTTP uses iso-latin-1 as character set, while some authentication
382#	backends such as LDAP expects UTF-8. If this is set to on Squid will
383#	translate the HTTP iso-latin-1 charset to UTF-8 before sending the
384#	username & password to the helper.
385#
386#	"children" numberofchildren [startup=N] [idle=N] [concurrency=N]
387#	The maximum number of authenticator processes to spawn (default 5).
388#	If you start too few Squid will have to wait for them to
389#	process a backlog of H(A1) calculations, slowing it down.
390#	When the H(A1) calculations are done via a (slow) network
391#	you are likely to need lots of authenticator processes.
392#
393#	The startup= and idle= options permit some skew in the exact amount
394#	run. A minimum of startup=N will begin during startup and reconfigure.
395#	Squid will start more in groups of up to idle=N in an attempt to meet
396#	traffic needs and to keep idle=N free above those traffic needs up to
397#	the maximum.
398#
399#	The concurrency= option sets the number of concurrent requests the
400#	helper can process.  The default of 0 is used for helpers who only
401#	supports one request at a time. Setting this to a number greater than
402#	0 changes the protocol used to include a channel number first on the
403#	request/response line, allowing multiple requests to be sent to the
404#	same helper in parallel without waiting for the response.
405#	Must not be set unless it's known the helper supports this.
406#
407#	auth_param digest children 20 startup=0 idle=1
408#
409#	"realm" realmstring
410#	Specifies the realm name which is to be reported to the
411#	client for the digest proxy authentication scheme (part of
412#	the text the user will see when prompted their username and
413#	password). There is no default.
414#	auth_param digest realm Squid proxy-caching web server
415#
416#	"nonce_garbage_interval" timeinterval
417#	Specifies the interval that nonces that have been issued
418#	to client_agent's are checked for validity.
419#
420#	"nonce_max_duration" timeinterval
421#	Specifies the maximum length of time a given nonce will be
422#	valid for.
423#
424#	"nonce_max_count" number
425#	Specifies the maximum number of times a given nonce can be
426#	used.
427#
428#	"nonce_strictness" on|off
429#	Determines if squid requires strict increment-by-1 behavior
430#	for nonce counts, or just incrementing (off - for use when
431#	user agents generate nonce counts that occasionally miss 1
432#	(ie, 1,2,4,6)). Default off.
433#
434#	"check_nonce_count" on|off
435#	This directive if set to off can disable the nonce count check
436#	completely to work around buggy digest qop implementations in
437#	certain mainstream browser versions. Default on to check the
438#	nonce count to protect from authentication replay attacks.
439#
440#	"post_workaround" on|off
441#	This is a workaround to certain buggy browsers who sends
442#	an incorrect request digest in POST requests when reusing
443#	the same nonce as acquired earlier on a GET request.
444#
445#	=== NTLM scheme options follow ===
446#
447#	"program" cmdline
448#	Specify the command for the external NTLM authenticator.
449#	Such a program reads exchanged NTLMSSP packets with
450#	the browser via Squid until authentication is completed.
451#	If you use an NTLM authenticator, make sure you have 1 acl
452#	of type proxy_auth.  By default, the NTLM authenticator program
453#	is not used.
454#
455#	NOTE: In Debian the ntlm_auth program is distributed in the winbindd package
456#	      which is required for this auth scheme to work
457#
458#	auth_param ntlm program /usr/bin/ntlm_auth
459#
460#	"children" numberofchildren [startup=N] [idle=N]
461#	The maximum number of authenticator processes to spawn (default 5).
462#	If you start too few Squid will have to wait for them to
463#	process a backlog of credential verifications, slowing it
464#	down. When credential verifications are done via a (slow)
465#	network you are likely to need lots of authenticator
466#	processes.
467#
468#	The startup= and idle= options permit some skew in the exact amount
469#	run. A minimum of startup=N will begin during startup and reconfigure.
470#	Squid will start more in groups of up to idle=N in an attempt to meet
471#	traffic needs and to keep idle=N free above those traffic needs up to
472#	the maximum.
473#
474#	auth_param ntlm children 20 startup=0 idle=1
475#
476#	"keep_alive" on|off
477#	If you experience problems with PUT/POST requests when using the
478#	Negotiate authentication scheme then you can try setting this to
479#	off. This will cause Squid to forcibly close the connection on
480#	the initial requests where the browser asks which schemes are
481#	supported by the proxy.
482#
483#	auth_param ntlm keep_alive on
484#
485#	=== Options for configuring the NEGOTIATE auth-scheme follow ===
486#
487#	"program" cmdline
488#	Specify the command for the external Negotiate authenticator.
489#	This protocol is used in Microsoft Active-Directory enabled setups with
490#	the Microsoft Internet Explorer or Mozilla Firefox browsers.
491#	Its main purpose is to exchange credentials with the Squid proxy
492#	using the Kerberos mechanisms.
493#	If you use a Negotiate authenticator, make sure you have at least
494#	one acl of type proxy_auth active. By default, the negotiate
495#	authenticator program is not used.
496#	The only supported program for this role is the ntlm_auth
497#	program distributed as part of Samba, version 4 or later.
498#
499#	NOTE: In Debian the ntlm_auth program is distributed in the winbindd package
500#	      which is required for this auth scheme to work
501#
502#	auth_param negotiate program /usr/bin/ntlm_auth --helper-protocol=gss-spnego
503#
504#	"children" numberofchildren [startup=N] [idle=N]
505#	The maximum number of authenticator processes to spawn (default 5).
506#	If you start too few Squid will have to wait for them to
507#	process a backlog of credential verifications, slowing it
508#	down. When credential verifications are done via a (slow)
509#	network you are likely to need lots of authenticator
510#	processes.
511#
512#	The startup= and idle= options permit some skew in the exact amount
513#	run. A minimum of startup=N will begin during startup and reconfigure.
514#	Squid will start more in groups of up to idle=N in an attempt to meet
515#	traffic needs and to keep idle=N free above those traffic needs up to
516#	the maximum.
517#
518#	auth_param negotiate children 20 startup=0 idle=1
519#
520#	"keep_alive" on|off
521#	If you experience problems with PUT/POST requests when using the
522#	Negotiate authentication scheme then you can try setting this to
523#	off. This will cause Squid to forcibly close the connection on
524#	the initial requests where the browser asks which schemes are
525#	supported by the proxy.
526#
527#	auth_param negotiate keep_alive on
528#
529#	
530#	Examples:
531#
532##Recommended minimum configuration per scheme:
533##auth_param negotiate program <uncomment and complete this line to activate>
534##auth_param negotiate children 20 startup=0 idle=1
535##auth_param negotiate keep_alive on
536##
537##auth_param ntlm program <uncomment and complete this line to activate>
538##auth_param ntlm children 20 startup=0 idle=1
539##auth_param ntlm keep_alive on
540##
541##auth_param digest program <uncomment and complete this line>
542##auth_param digest children 20 startup=0 idle=1
543##auth_param digest realm Squid proxy-caching web server
544##auth_param digest nonce_garbage_interval 5 minutes
545##auth_param digest nonce_max_duration 30 minutes
546##auth_param digest nonce_max_count 50
547##
548##auth_param basic program <uncomment and complete this line>
549##auth_param basic children 5 startup=5 idle=1
550##auth_param basic realm Squid proxy-caching web server
551##auth_param basic credentialsttl 2 hours
552#Default:
553# none
554
555#  TAG: authenticate_cache_garbage_interval
556#	The time period between garbage collection across the username cache.
557#	This is a trade-off between memory utilization (long intervals - say
558#	2 days) and CPU (short intervals - say 1 minute). Only change if you
559#	have good reason to.
560#Default:
561# authenticate_cache_garbage_interval 1 hour
562
563#  TAG: authenticate_ttl
564#	The time a user & their credentials stay in the logged in
565#	user cache since their last request. When the garbage
566#	interval passes, all user credentials that have passed their
567#	TTL are removed from memory.
568#Default:
569# authenticate_ttl 1 hour
570
571#  TAG: authenticate_ip_ttl
572#	If you use proxy authentication and the 'max_user_ip' ACL,
573#	this directive controls how long Squid remembers the IP
574#	addresses associated with each user.  Use a small value
575#	(e.g., 60 seconds) if your users might change addresses
576#	quickly, as is the case with dialup.   You might be safe
577#	using a larger value (e.g., 2 hours) in a corporate LAN
578#	environment with relatively static address assignments.
579#Default:
580# authenticate_ip_ttl 1 second
581
582# ACCESS CONTROLS
583# -----------------------------------------------------------------------------
584
585#  TAG: external_acl_type
586#	This option defines external acl classes using a helper program
587#	to look up the status
588#
589#	  external_acl_type name [options] FORMAT.. /path/to/helper [helper arguments..]
590#
591#	Options:
592#
593#	  ttl=n		TTL in seconds for cached results (defaults to 3600
594#	  		for 1 hour)
595#	  negative_ttl=n
596#	  		TTL for cached negative lookups (default same
597#	  		as ttl)
598#	  children-max=n
599#			Maximum number of acl helper processes spawned to service
600#			external acl lookups of this type. (default 20)
601#	  children-startup=n
602#			Minimum number of acl helper processes to spawn during
603#			startup and reconfigure to service external acl lookups
604#			of this type. (default 0)
605#	  children-idle=n
606#			Number of acl helper processes to keep ahead of traffic
607#			loads. Squid will spawn this many at once whenever load
608#			rises above the capabilities of existing processes.
609#			Up to the value of children-max. (default 1)
610#	  concurrency=n	concurrency level per process. Only used with helpers
611#			capable of processing more than one query at a time.
612#	  cache=n	limit the result cache size, default is 262144.
613#	  grace=n	Percentage remaining of TTL where a refresh of a
614#			cached entry should be initiated without needing to
615#			wait for a new reply. (default is for no grace period)
616#	  protocol=2.5	Compatibility mode for Squid-2.5 external acl helpers
617#	  ipv4 / ipv6	IP protocol used to communicate with this helper.
618#			The default is to auto-detect IPv6 and use it when available.
619#
620#	FORMAT specifications
621#
622#	  %LOGIN	Authenticated user login name
623#	  %EXT_USER	Username from previous external acl
624#	  %EXT_LOG	Log details from previous external acl
625#	  %EXT_TAG	Tag from previous external acl
626#	  %IDENT	Ident user name
627#	  %SRC		Client IP
628#	  %SRCPORT	Client source port
629#	  %URI		Requested URI
630#	  %DST		Requested host
631#	  %PROTO	Requested protocol
632#	  %PORT		Requested port
633#	  %PATH		Requested URL path
634#	  %METHOD	Request method
635#	  %MYADDR	Squid interface address
636#	  %MYPORT	Squid http_port number
637#	  %PATH		Requested URL-path (including query-string if any)
638#	  %USER_CERT	SSL User certificate in PEM format
639#	  %USER_CERTCHAIN SSL User certificate chain in PEM format
640#	  %USER_CERT_xx	SSL User certificate subject attribute xx
641#	  %USER_CA_CERT_xx SSL User certificate issuer attribute xx
642#
643#	  %>{Header}	HTTP request header "Header"
644#	  %>{Hdr:member}
645#	  		HTTP request header "Hdr" list member "member"
646#	  %>{Hdr:;member}
647#	  		HTTP request header list member using ; as
648#	  		list separator. ; can be any non-alphanumeric
649#			character.
650#
651#	  %<{Header}	HTTP reply header "Header"
652#	  %<{Hdr:member}
653#	  		HTTP reply header "Hdr" list member "member"
654#	  %<{Hdr:;member}
655#	  		HTTP reply header list member using ; as
656#	  		list separator. ; can be any non-alphanumeric
657#			character.
658#
659#	  %ACL		The name of the ACL being tested.
660#	  %DATA		The ACL arguments. If not used then any arguments
661#			is automatically added at the end of the line
662#			sent to the helper.
663#			NOTE: this will encode the arguments as one token,
664#			whereas the default will pass each separately.
665#
666#	  %%		The percent sign. Useful for helpers which need
667#			an unchanging input format.
668#
669#
670#	General request syntax:
671#
672#	  [channel-ID] FORMAT-values [acl-values ...]
673#
674#
675#	FORMAT-values consists of transaction details expanded with
676#	whitespace separation per the config file FORMAT specification
677#	using the FORMAT macros listed above.
678#
679#	acl-values consists of any string specified in the referencing
680#	config 'acl ... external' line. see the "acl external" directive.
681#
682#	Request values sent to the helper are URL escaped to protect
683#	each value in requests against whitespaces.
684#
685#	If using protocol=2.5 then the request sent to the helper is not
686#	URL escaped to protect against whitespace.
687#
688#	NOTE: protocol=3.0 is deprecated as no longer necessary.
689#
690#	When using the concurrency= option the protocol is changed by
691#	introducing a query channel tag in front of the request/response.
692#	The query channel tag is a number between 0 and concurrency-1.
693#	This value must be echoed back unchanged to Squid as the first part
694#	of the response relating to its request.
695#
696#
697#	The helper receives lines expanded per the above format specification
698#	and for each input line returns 1 line starting with OK/ERR/BH result
699#	code and optionally followed by additional keywords with more details.
700#
701#
702#	General result syntax:
703#
704#	  [channel-ID] result keyword=value ...
705#
706#	Result consists of one of the codes:
707#
708#	  OK
709#		the ACL test produced a match.
710#
711#	  ERR
712#		the ACL test does not produce a match.
713#
714#	  BH
715#		An internal error occurred in the helper, preventing
716#		a result being identified.
717#
718#	The meaning of 'a match' is determined by your squid.conf
719#	access control configuration. See the Squid wiki for details.
720#
721#	Defined keywords:
722#
723#	  user=		The users name (login)
724#
725#	  password=	The users password (for login= cache_peer option)
726#
727#	  message=	Message describing the reason for this response.
728#			Available as %o in error pages.
729#			Useful on (ERR and BH results).
730#
731#	  tag=		Apply a tag to a request. Only sets a tag once,
732#			does not alter existing tags.
733#
734#	  log=		String to be logged in access.log. Available as
735#	  		%ea in logformat specifications.
736#
737#	Any keywords may be sent on any response whether OK, ERR or BH.
738#
739#	All response keyword values need to be a single token with URL
740#	escaping, or enclosed in double quotes (") and escaped using \ on
741#	any double quotes or \ characters within the value. The wrapping
742#	double quotes are removed before the value is interpreted by Squid.
743#	\r and \n are also replace by CR and LF.
744#
745#	Some example key values:
746#
747#		user=John%20Smith
748#		user="John Smith"
749#		user="J. \"Bob\" Smith"
750#Default:
751# none
752
753#  TAG: acl
754#	Defining an Access List
755#
756#	Every access list definition must begin with an aclname and acltype, 
757#	followed by either type-specific arguments or a quoted filename that
758#	they are read from.
759#
760#	   acl aclname acltype argument ...
761#	   acl aclname acltype "file" ...
762#
763#	When using "file", the file should contain one item per line.
764#
765#	Some acl types supports options which changes their default behaviour.
766#	The available options are:
767#
768#	-i,+i	By default, regular expressions are CASE-SENSITIVE. To make them
769#		case-insensitive, use the -i option. To return case-sensitive
770#		use the +i option between patterns, or make a new ACL line
771#		without -i.	
772#
773#	-n	Disable lookups and address type conversions.  If lookup or
774#		conversion is required because the parameter type (IP or
775#		domain name) does not match the message address type (domain
776#		name or IP), then the ACL would immediately declare a mismatch
777#		without any warnings or lookups.
778#
779#	--	Used to stop processing all options, in the case the first acl
780#		value has '-' character as first character (for example the '-'
781#		is a valid domain name)
782#
783#	Some acl types require suspending the current request in order
784#	to access some external data source.
785#	Those which do are marked with the tag [slow], those which
786#	don't are marked as [fast].
787#	See http://wiki.squid-cache.org/SquidFaq/SquidAcl
788#	for further information
789#
790#	***** ACL TYPES AVAILABLE *****
791#
792#	acl aclname src ip-address/mask ...	# clients IP address [fast]
793#	acl aclname src addr1-addr2/mask ...	# range of addresses [fast]
794#	acl aclname dst [-n] ip-address/mask ...	# URL host's IP address [slow]
795#	acl aclname localip ip-address/mask ... # IP address the client connected to [fast]
796#
797#	acl aclname arp      mac-address ... (xx:xx:xx:xx:xx:xx notation)
798#	  # The arp ACL requires the special configure option --enable-arp-acl.
799#	  # Furthermore, the ARP ACL code is not portable to all operating systems.
800#	  # It works on Linux, Solaris, Windows, FreeBSD, and some
801#	  # other *BSD variants.
802#	  # [fast]
803#	  #
804#	  # NOTE: Squid can only determine the MAC address for clients that are on
805#	  # the same subnet. If the client is on a different subnet,
806#	  # then Squid cannot find out its MAC address.
807#
808#	acl aclname srcdomain   .foo.com ...
809#	  # reverse lookup, from client IP [slow]
810#	acl aclname dstdomain [-n] .foo.com ...
811#	  # Destination server from URL [fast]
812#	acl aclname srcdom_regex [-i] \.foo\.com ...
813#	  # regex matching client name [slow]
814#	acl aclname dstdom_regex [-n] [-i] \.foo\.com ...
815#	  # regex matching server [fast]
816#	  #
817#	  # For dstdomain and dstdom_regex a reverse lookup is tried if a IP
818#	  # based URL is used and no match is found. The name "none" is used
819#	  # if the reverse lookup fails.
820#
821#	acl aclname src_as number ...
822#	acl aclname dst_as number ...
823#	  # [fast]
824#	  # Except for access control, AS numbers can be used for
825#	  # routing of requests to specific caches. Here's an
826#	  # example for routing all requests for AS#1241 and only
827#	  # those to mycache.mydomain.net:
828#	  # acl asexample dst_as 1241
829#	  # cache_peer_access mycache.mydomain.net allow asexample
830#	  # cache_peer_access mycache_mydomain.net deny all
831#
832#	acl aclname peername myPeer ...
833#	  # [fast]
834#	  # match against a named cache_peer entry
835#	  # set unique name= on cache_peer lines for reliable use.
836#
837#	acl aclname time [day-abbrevs] [h1:m1-h2:m2]
838#	  # [fast]
839#	  #  day-abbrevs:
840#	  #	S - Sunday
841#	  #	M - Monday
842#	  #	T - Tuesday
843#	  #	W - Wednesday
844#	  #	H - Thursday
845#	  #	F - Friday
846#	  #	A - Saturday
847#	  #  h1:m1 must be less than h2:m2
848#
849#	acl aclname url_regex [-i] ^http:// ...
850#	  # regex matching on whole URL [fast]
851#	acl aclname urllogin [-i] [^a-zA-Z0-9] ...
852#	  # regex matching on URL login field
853#	acl aclname urlpath_regex [-i] \.gif$ ...
854#	  # regex matching on URL path [fast]
855#
856#	acl aclname port 80 70 21 0-1024...   # destination TCP port [fast]
857#	                                      # ranges are alloed
858#	acl aclname localport 3128 ...	      # TCP port the client connected to [fast]
859#	                                      # NP: for interception mode this is usually '80'
860#
861#	acl aclname myportname 3128 ...       # http(s)_port name [fast]
862#
863#	acl aclname proto HTTP FTP ...        # request protocol [fast]
864# 
865#	acl aclname method GET POST ...       # HTTP request method [fast]
866#
867#	acl aclname http_status 200 301 500- 400-403 ... 
868#	  # status code in reply [fast]
869#
870#	acl aclname browser [-i] regexp ...
871#	  # pattern match on User-Agent header (see also req_header below) [fast]
872#
873#	acl aclname referer_regex [-i] regexp ...
874#	  # pattern match on Referer header [fast]
875#	  # Referer is highly unreliable, so use with care
876#
877#	acl aclname ident username ...
878#	acl aclname ident_regex [-i] pattern ...
879#	  # string match on ident output [slow]
880#	  # use REQUIRED to accept any non-null ident.
881#
882#	acl aclname proxy_auth [-i] username ...
883#	acl aclname proxy_auth_regex [-i] pattern ...
884#	  # perform http authentication challenge to the client and match against
885#	  # supplied credentials [slow]
886#	  #
887#	  # takes a list of allowed usernames.
888#	  # use REQUIRED to accept any valid username.
889#	  #
890#	  # Will use proxy authentication in forward-proxy scenarios, and plain
891#	  # http authenticaiton in reverse-proxy scenarios
892#	  #
893#	  # NOTE: when a Proxy-Authentication header is sent but it is not
894#	  # needed during ACL checking the username is NOT logged
895#	  # in access.log.
896#	  #
897#	  # NOTE: proxy_auth requires a EXTERNAL authentication program
898#	  # to check username/password combinations (see
899#	  # auth_param directive).
900#	  #
901#	  # NOTE: proxy_auth can't be used in a transparent/intercepting proxy
902#	  # as the browser needs to be configured for using a proxy in order
903#	  # to respond to proxy authentication.
904#
905#	acl aclname snmp_community string ...
906#	  # A community string to limit access to your SNMP Agent [fast]
907#	  # Example:
908#	  #
909#	  #	acl snmppublic snmp_community public
910#
911#	acl aclname maxconn number
912#	  # This will be matched when the client's IP address has
913#	  # more than <number> TCP connections established. [fast]
914#	  # NOTE: This only measures direct TCP links so X-Forwarded-For
915#	  # indirect clients are not counted.
916#
917#	acl aclname max_user_ip [-s] number
918#	  # This will be matched when the user attempts to log in from more
919#	  # than <number> different ip addresses. The authenticate_ip_ttl
920#	  # parameter controls the timeout on the ip entries. [fast]
921#	  # If -s is specified the limit is strict, denying browsing
922#	  # from any further IP addresses until the ttl has expired. Without
923#	  # -s Squid will just annoy the user by "randomly" denying requests.
924#	  # (the counter is reset each time the limit is reached and a
925#	  # request is denied)
926#	  # NOTE: in acceleration mode or where there is mesh of child proxies,
927#	  # clients may appear to come from multiple addresses if they are
928#	  # going through proxy farms, so a limit of 1 may cause user problems.
929#
930#	acl aclname random probability
931#	  # Pseudo-randomly match requests. Based on the probability given.
932#	  # Probability may be written as a decimal (0.333), fraction (1/3)
933#	  # or ratio of matches:non-matches (3:5).
934#
935#	acl aclname req_mime_type [-i] mime-type ...
936#	  # regex match against the mime type of the request generated
937#	  # by the client. Can be used to detect file upload or some
938#	  # types HTTP tunneling requests [fast]
939#	  # NOTE: This does NOT match the reply. You cannot use this
940#	  # to match the returned file type.
941#
942#	acl aclname req_header header-name [-i] any\.regex\.here
943#	  # regex match against any of the known request headers.  May be
944#	  # thought of as a superset of "browser", "referer" and "mime-type"
945#	  # ACL [fast]
946#
947#	acl aclname rep_mime_type [-i] mime-type ...
948#	  # regex match against the mime type of the reply received by
949#	  # squid. Can be used to detect file download or some
950#	  # types HTTP tunneling requests. [fast]
951#	  # NOTE: This has no effect in http_access rules. It only has
952#	  # effect in rules that affect the reply data stream such as
953#	  # http_reply_access.
954#
955#	acl aclname rep_header header-name [-i] any\.regex\.here
956#	  # regex match against any of the known reply headers. May be
957#	  # thought of as a superset of "browser", "referer" and "mime-type"
958#	  # ACLs [fast]
959#
960#	acl aclname external class_name [arguments...]
961#	  # external ACL lookup via a helper class defined by the
962#	  # external_acl_type directive [slow]
963#
964#	acl aclname user_cert attribute values...
965#	  # match against attributes in a user SSL certificate
966#	  # attribute is one of DN/C/O/CN/L/ST [fast]
967#
968#	acl aclname ca_cert attribute values...
969#	  # match against attributes a users issuing CA SSL certificate
970#	  # attribute is one of DN/C/O/CN/L/ST [fast]
971#
972#	acl aclname ext_user username ...
973#	acl aclname ext_user_regex [-i] pattern ...
974#	  # string match on username returned by external acl helper [slow]
975#	  # use REQUIRED to accept any non-null user name.
976#
977#	acl aclname tag tagvalue ...
978#	  # string match on tag returned by external acl helper [slow]
979#
980#	acl aclname hier_code codename ...
981#	  # string match against squid hierarchy code(s); [fast]
982#	  #  e.g., DIRECT, PARENT_HIT, NONE, etc.
983#	  #
984#	  # NOTE: This has no effect in http_access rules. It only has
985#	  # effect in rules that affect the reply data stream such as
986#	  # http_reply_access.
987#
988#	acl aclname note name [value ...]
989#	  # match transaction annotation [fast]
990#	  # Without values, matches any annotation with a given name.
991#	  # With value(s), matches any annotation with a given name that
992#	  # also has one of the given values.
993#	  # Names and values are compared using a string equality test.
994#	  # Annotation sources include note and adaptation_meta directives
995#	  # as well as helper and eCAP responses.
996#
997#	acl aclname any-of acl1 acl2 ...
998#	  # match any one of the acls [fast or slow]
999#	  # The first matching ACL stops further ACL evaluation.
1000#	  #
1001#	  # ACLs from multiple any-of lines with the same name are ORed.
1002#	  # For example, A = (a1 or a2) or (a3 or a4) can be written as
1003#	  #   acl A any-of a1 a2
1004#	  #   acl A any-of a3 a4
1005#	  #
1006#	  # This group ACL is fast if all evaluated ACLs in the group are fast
1007#	  # and slow otherwise.
1008#
1009#	acl aclname all-of acl1 acl2 ... 
1010#	  # match all of the acls [fast or slow]
1011#	  # The first mismatching ACL stops further ACL evaluation.
1012#	  #
1013#	  # ACLs from multiple all-of lines with the same name are ORed.
1014#	  # For example, B = (b1 and b2) or (b3 and b4) can be written as
1015#	  #   acl B all-of b1 b2
1016#	  #   acl B all-of b3 b4
1017#	  #
1018#	  # This group ACL is fast if all evaluated ACLs in the group are fast
1019#	  # and slow otherwise.
1020#
1021#	Examples:
1022#		acl macaddress arp 09:00:2b:23:45:67
1023#		acl myexample dst_as 1241
1024#		acl password proxy_auth REQUIRED
1025#		acl fileupload req_mime_type -i ^multipart/form-data$
1026#		acl javascript rep_mime_type -i ^application/x-javascript$
1027#
1028#Default:
1029# ACLs all, manager, localhost, and to_localhost are predefined.
1030#
1031#
1032# Recommended minimum configuration:
1033#
1034
1035# Example rule allowing access from your local networks.
1036# Adapt to list your (internal) IP networks from where browsing
1037# should be allowed
1038#acl localnet src 10.0.0.0/8	# RFC1918 possible internal network
1039#acl localnet src 172.16.0.0/12	# RFC1918 possible internal network
1040#acl localnet src 192.168.0.0/16	# RFC1918 possible internal network
1041#acl localnet src fc00::/7       # RFC 4193 local private network range
1042#acl localnet src fe80::/10      # RFC 4291 link-local (directly plugged) machines
1043
1044acl ads dstdom_regex "/etc/squid3/ad_block.txt"
1045http_access deny ads
1046
1047acl SSL_ports port 443
1048acl Safe_ports port 80		# http
1049acl Safe_ports port 21		# ftp
1050acl Safe_ports port 443		# https
1051acl Safe_ports port 70		# gopher
1052acl Safe_ports port 210		# wais
1053acl Safe_ports port 1025-65535	# unregistered ports
1054acl Safe_ports port 280		# http-mgmt
1055acl Safe_ports port 488		# gss-http
1056acl Safe_ports port 591		# filemaker
1057acl Safe_ports port 777		# multiling http
1058acl CONNECT method CONNECT
1059
1060#  TAG: follow_x_forwarded_for
1061#	Allowing or Denying the X-Forwarded-For header to be followed to
1062#	find the original source of a request.
1063#
1064#	Requests may pass through a chain of several other proxies
1065#	before reaching us.  The X-Forwarded-For header will contain a
1066#	comma-separated list of the IP addresses in the chain, with the
1067#	rightmost address being the most recent.
1068#
1069#	If a request reaches us from a source that is allowed by this
1070#	configuration item, then we consult the X-Forwarded-For header
1071#	to see where that host received the request from.  If the
1072#	X-Forwarded-For header contains multiple addresses, we continue
1073#	backtracking until we reach an address for which we are not allowed
1074#	to follow the X-Forwarded-For header, or until we reach the first
1075#	address in the list. For the purpose of ACL used in the
1076#	follow_x_forwarded_for directive the src ACL type always matches
1077#	the address we are testing and srcdomain matches its rDNS.
1078#
1079#	The end result of this process is an IP address that we will
1080#	refer to as the indirect client address.  This address may
1081#	be treated as the client address for access control, ICAP, delay
1082#	pools and logging, depending on the acl_uses_indirect_client,
1083#	icap_uses_indirect_client, delay_pool_uses_indirect_client, 
1084#	log_uses_indirect_client and tproxy_uses_indirect_client options.
1085#
1086#	This clause only supports fast acl types.
1087#	See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1088#
1089#	SECURITY CONSIDERATIONS:
1090#
1091#		Any host for which we follow the X-Forwarded-For header
1092#		can place incorrect information in the header, and Squid
1093#		will use the incorrect information as if it were the
1094#		source address of the request.  This may enable remote
1095#		hosts to bypass any access control restrictions that are
1096#		based on the client's source addresses.
1097#
1098#	For example:
1099#
1100#		acl localhost src 127.0.0.1
1101#		acl my_other_proxy srcdomain .proxy.example.com
1102#		follow_x_forwarded_for allow localhost
1103#		follow_x_forwarded_for allow my_other_proxy
1104#Default:
1105# X-Forwarded-For header will be ignored.
1106
1107#  TAG: acl_uses_indirect_client	on|off
1108#	Controls whether the indirect client address
1109#	(see follow_x_forwarded_for) is used instead of the
1110#	direct client address in acl matching.
1111#
1112#	NOTE: maxconn ACL considers direct TCP links and indirect
1113#	      clients will always have zero. So no match.
1114#Default:
1115# acl_uses_indirect_client on
1116
1117#  TAG: delay_pool_uses_indirect_client	on|off
1118#	Controls whether the indirect client address
1119#	(see follow_x_forwarded_for) is used instead of the
1120#	direct client address in delay pools.
1121#Default:
1122# delay_pool_uses_indirect_client on
1123
1124#  TAG: log_uses_indirect_client	on|off
1125#	Controls whether the indirect client address
1126#	(see follow_x_forwarded_for) is used instead of the
1127#	direct client address in the access log.
1128#Default:
1129# log_uses_indirect_client on
1130
1131#  TAG: tproxy_uses_indirect_client	on|off
1132#	Controls whether the indirect client address
1133#	(see follow_x_forwarded_for) is used instead of the
1134#	direct client address when spoofing the outgoing client.
1135#
1136#	This has no effect on requests arriving in non-tproxy
1137#	mode ports.
1138#
1139#	SECURITY WARNING: Usage of this option is dangerous
1140#	and should not be used trivially. Correct configuration
1141#	of follow_x_forewarded_for with a limited set of trusted
1142#	sources is required to prevent abuse of your proxy.
1143#Default:
1144# tproxy_uses_indirect_client off
1145
1146#  TAG: spoof_client_ip
1147#	Control client IP address spoofing of TPROXY traffic based on
1148#	defined access lists.
1149#
1150#	spoof_client_ip allow|deny [!]aclname ...
1151#
1152#	If there are no "spoof_client_ip" lines present, the default
1153#	is to "allow" spoofing of any suitable request.
1154#
1155#	Note that the cache_peer "no-tproxy" option overrides this ACL.
1156#
1157#	This clause supports fast acl types.
1158#	See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1159#Default:
1160# Allow spoofing on all TPROXY traffic.
1161
1162#  TAG: http_access
1163#	Allowing or Denying access based on defined access lists
1164#
1165#	Access to the HTTP port:
1166#	http_access allow|deny [!]aclname ...
1167#
1168#	NOTE on default values:
1169#
1170#	If there are no "access" lines present, the default is to deny
1171#	the request.
1172#
1173#	If none of the "access" lines cause a match, the default is the
1174#	opposite of the last line in the list.  If the last line was
1175#	deny, the default is allow.  Conversely, if the last line
1176#	is allow, the default will be deny.  For these reasons, it is a
1177#	good idea to have an "deny all" entry at the end of your access
1178#	lists to avoid potential confusion.
1179#
1180#	This clause supports both fast and slow acl types.
1181#	See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1182#
1183#Default:
1184# Deny, unless rules exist in squid.conf.
1185#
1186
1187#
1188# Recommended minimum Access Permission configuration:
1189#
1190# Deny requests to certain unsafe ports
1191http_access deny !Safe_ports
1192
1193# Deny CONNECT to other than secure SSL ports
1194http_access deny CONNECT !SSL_ports
1195
1196# Only allow cachemgr access from localhost
1197http_access allow localhost manager
1198http_access deny manager
1199
1200# We strongly recommend the following be uncommented to protect innocent
1201# web applications running on the proxy server who think the only
1202# one who can access services on "localhost" is a local user
1203#http_access deny to_localhost
1204
1205#
1206# INSERT YOUR OWN RULE(S) HERE TO ALLOW ACCESS FROM YOUR CLIENTS
1207#
1208
1209# Example rule allowing access from your local networks.
1210# Adapt localnet in the ACL section to list your (internal) IP networks
1211# from where browsing should be allowed
1212#http_access allow localnet
1213http_access allow all
1214
1215# And finally deny all other access to this proxy
1216http_access deny all
1217
1218#  TAG: adapted_http_access
1219#	Allowing or Denying access based on defined access lists
1220#
1221#	Essentially identical to http_access, but runs after redirectors
1222#	and ICAP/eCAP adaptation. Allowing access control based on their
1223#	output.
1224#
1225#	If not set then only http_access is used.
1226#Default:
1227# Allow, unless rules exist in squid.conf.
1228
1229#  TAG: http_reply_access
1230#	Allow replies to client requests. This is complementary to http_access.
1231#
1232#	http_reply_access allow|deny [!] aclname ...
1233#
1234#	NOTE: if there are no access lines present, the default is to allow
1235#	all replies.
1236#
1237#	If none of the access lines cause a match the opposite of the
1238#	last line will apply. Thus it is good practice to end the rules
1239#	with an "allow all" or "deny all" entry.
1240#
1241#	This clause supports both fast and slow acl types.
1242#	See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1243#Default:
1244# Allow, unless rules exist in squid.conf.
1245
1246#  TAG: icp_access
1247#	Allowing or Denying access to the ICP port based on defined
1248#	access lists
1249#
1250#	icp_access  allow|deny [!]aclname ...
1251#
1252#	NOTE: The default if no icp_access lines are present is to
1253#	deny all traffic. This default may cause problems with peers
1254#	using ICP.
1255#
1256#	This clause only supports fast acl types.
1257#	See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1258#
1259## Allow ICP queries from local networks only
1260##icp_access allow localnet
1261##icp_access deny all
1262#Default:
1263# Deny, unless rules exist in squid.conf.
1264
1265#  TAG: htcp_access
1266#	Allowing or Denying access to the HTCP port based on defined
1267#	access lists
1268#
1269#	htcp_access  allow|deny [!]aclname ...
1270#
1271#	See also htcp_clr_access for details on access control for
1272#	cache purge (CLR) HTCP messages.
1273#
1274#	NOTE: The default if no htcp_access lines are present is to
1275#	deny all traffic. This default may cause problems with peers
1276#	using the htcp option.
1277#
1278#	This clause only supports fast acl types.
1279#	See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1280#
1281## Allow HTCP queries from local networks only
1282##htcp_access allow localnet
1283##htcp_access deny all
1284#Default:
1285# Deny, unless rules exist in squid.conf.
1286
1287#  TAG: htcp_clr_access
1288#	Allowing or Denying access to purge content using HTCP based
1289#	on defined access lists.
1290#	See htcp_access for details on general HTCP access control.
1291#
1292#	htcp_clr_access  allow|deny [!]aclname ...
1293#
1294#	This clause only supports fast acl types.
1295#	See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1296#
1297## Allow HTCP CLR requests from trusted peers
1298#acl htcp_clr_peer src 192.0.2.2 2001:DB8::2
1299#htcp_clr_access allow htcp_clr_peer
1300#htcp_clr_access deny all
1301#Default:
1302# Deny, unless rules exist in squid.conf.
1303
1304#  TAG: miss_access
1305#	Determins whether network access is permitted when satisfying a request.
1306#
1307#	For example;
1308#	    to force your neighbors to use you as a sibling instead of
1309#	    a parent.
1310#
1311#		acl localclients src 192.0.2.0/24 2001:DB8::a:0/64
1312#		miss_access deny  !localclients
1313#		miss_access allow all
1314#
1315#	This means only your local clients are allowed to fetch relayed/MISS
1316#	replies from the network and all other clients can only fetch cached
1317#	objects (HITs).
1318#
1319#	The default for this setting allows all clients who passed the
1320#	http_access rules to relay via this proxy.
1321#
1322#	This clause only supports fast acl types.
1323#	See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1324#Default:
1325# Allow, unless rules exist in squid.conf.
1326
1327#  TAG: ident_lookup_access
1328#	A list of ACL elements which, if matched, cause an ident
1329#	(RFC 931) lookup to be performed for this request.  For
1330#	example, you might choose to always perform ident lookups
1331#	for your main multi-user Unix boxes, but not for your Macs
1332#	and PCs.  By default, ident lookups are not performed for
1333#	any requests.
1334#
1335#	To enable ident lookups for specific client addresses, you
1336#	can follow this example:
1337#
1338#	acl ident_aware_hosts src 198.168.1.0/24
1339#	ident_lookup_access allow ident_aware_hosts
1340#	ident_lookup_access deny all
1341#
1342#	Only src type ACL checks are fully supported.  A srcdomain
1343#	ACL might work at times, but it will not always provide
1344#	the correct result.
1345#
1346#	This clause only supports fast acl types.
1347#	See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1348#Default:
1349# Unless rules exist in squid.conf, IDENT is not fetched.
1350
1351#  TAG: reply_body_max_size	size [acl acl...]
1352#	This option specifies the maximum size of a reply body. It can be
1353#	used to prevent users from downloading very large files, such as
1354#	MP3's and movies. When the reply headers are received, the
1355#	reply_body_max_size lines are processed, and the first line where
1356#	all (if any) listed ACLs are true is used as the maximum body size
1357#	for this reply.
1358#
1359#	This size is checked twice. First when we get the reply headers,
1360#	we check the content-length value.  If the content length value exists
1361#	and is larger than the allowed size, the request is denied and the
1362#	user receives an error message that says "the request or reply
1363#	is too large." If there is no content-length, and the reply
1364#	size exceeds this limit, the client's connection is just closed
1365#	and they will receive a partial reply.
1366#
1367#	WARNING: downstream caches probably can not detect a partial reply
1368#	if there is no content-length header, so they will cache
1369#	partial responses and give them out as hits.  You should NOT
1370#	use this option if you have downstream caches.
1371#
1372#	WARNING: A maximum size smaller than the size of squid's error messages
1373#	will cause an infinite loop and crash squid. Ensure that the smallest
1374#	non-zero value you use is greater that the maximum header size plus
1375#	the size of your largest error page.
1376#
1377#	If you set this parameter none (the default), there will be
1378#	no limit imposed.
1379#
1380#	Configuration Format is:
1381#		reply_body_max_size SIZE UNITS [acl ...]
1382#	ie.
1383#		reply_body_max_size 10 MB
1384#
1385#Default:
1386# No limit is applied.
1387
1388# NETWORK OPTIONS
1389# -----------------------------------------------------------------------------
1390
1391#  TAG: http_port
1392#	Usage:	port [mode] [options]
1393#		hostname:port [mode] [options]
1394#		1.2.3.4:port [mode] [options]
1395#
1396#	The socket addresses where Squid will listen for HTTP client
1397#	requests.  You may specify multiple socket addresses.
1398#	There are three forms: port alone, hostname with port, and
1399#	IP address with port.  If you specify a hostname or IP
1400#	address, Squid binds the socket to that specific
1401#	address. Most likely, you do not need to bind to a specific
1402#	address, so you can use the port number alone.
1403#
1404#	If you are running Squid in accelerator mode, you
1405#	probably want to listen on port 80 also, or instead.
1406#
1407#	The -a command line option may be used to specify additional
1408#	port(s) where Squid listens for proxy request. Such ports will
1409#	be plain proxy ports with no options.
1410#
1411#	You may specify multiple socket addresses on multiple lines.
1412#
1413#	Modes:
1414#
1415#	   intercept	Support for IP-Layer interception of
1416#			outgoing requests without browser settings.
1417#			NP: disables authentication and IPv6 on the port.
1418#
1419#	   tproxy	Support Linux TPROXY for spoofing outgoing
1420#			connections using the client IP address.
1421#			NP: disables authentication and maybe IPv6 on the port.
1422#
1423#	   accel	Accelerator / reverse proxy mode
1424#
1425#	   ssl-bump	For each CONNECT request allowed by ssl_bump ACLs,
1426#			establish secure connection with the client and with
1427#			the server, decrypt HTTPS messages as they pass through
1428#			Squid, and treat them as unencrypted HTTP messages,
1429#			becoming the man-in-the-middle.
1430#
1431#			The ssl_bump option is required to fully enable
1432#			bumping of CONNECT requests.
1433#
1434#	Omitting the mode flag causes default forward proxy mode to be used.
1435#
1436#
1437#	Accelerator Mode Options:
1438#
1439#	   defaultsite=domainname
1440#			What to use for the Host: header if it is not present
1441#			in a request. Determines what site (not origin server)
1442#			accelerators should consider the default.
1443#
1444#	   no-vhost	Disable using HTTP/1.1 Host header for virtual domain support.
1445#
1446#	   protocol=	Protocol to reconstruct accelerated requests with.
1447#			Defaults to http for http_port and https for
1448#			https_port
1449#
1450#	   vport	Virtual host port support. Using the http_port number
1451#			instead of the port passed on Host: headers.
1452#
1453#	   vport=NN	Virtual host port support. Using the specified port
1454#			number instead of the port passed on Host: headers.
1455#
1456#	   act-as-origin
1457#			Act as if this Squid is the origin server.
1458#			This currently means generate new Date: and Expires:
1459#			headers on HIT instead of adding Age:.
1460#
1461#	   ignore-cc	Ignore request Cache-Control headers.
1462#
1463#			WARNING: This option violates HTTP specifications if
1464#			used in non-accelerator setups.
1465#
1466#	   allow-direct	Allow direct forwarding in accelerator mode. Normally
1467#			accelerated requests are denied direct forwarding as if
1468#			never_direct was used.
1469#
1470#			WARNING: this option opens accelerator mode to security
1471#			vulnerabilities usually only affecting in interception
1472#			mode. Make sure to protect forwarding with suitable
1473#			http_access rules when using this.
1474#
1475#
1476#	SSL Bump Mode Options:
1477#	    In addition to these options ssl-bump requires TLS/SSL options.
1478#
1479#	   generate-host-certificates[=<on|off>]
1480#			Dynamically create SSL server certificates for the
1481#			destination hosts of bumped CONNECT requests.When 
1482#			enabled, the cert and key options are used to sign
1483#			generated certificates. Otherwise generated
1484#			certificate will be selfsigned.
1485#			If there is a CA certificate lifetime of the generated 
1486#			certificate equals lifetime of the CA certificate. If
1487#			generated certificate is selfsigned lifetime is three 
1488#			years.
1489#			This option is enabled by default when ssl-bump is used.
1490#			See the ssl-bump option above for more information.
1491#			
1492#	   dynamic_cert_mem_cache_size=SIZE
1493#			Approximate total RAM size spent on cached generated
1494#			certificates. If set to zero, caching is disabled. The
1495#			default value is 4MB.
1496#
1497#	TLS / SSL Options:
1498#
1499#	   cert=	Path to SSL certificate (PEM format).
1500#
1501#	   key=		Path to SSL private key file (PEM format)
1502#			if not specified, the certificate file is
1503#			assumed to be a combined certificate and
1504#			key file.
1505#
1506#	   version=	The version of SSL/TLS supported
1507#			    1	automatic (default)
1508#			    2	SSLv2 only
1509#			    3	SSLv3 only
1510#			    4	TLSv1.0 only
1511#			    5	TLSv1.1 only
1512#			    6	TLSv1.2 only
1513#
1514#	   cipher=	Colon separated list of supported ciphers.
1515#			NOTE: some ciphers such as EDH ciphers depend on
1516#			      additional settings. If those settings are
1517#			      omitted the ciphers may be silently ignored
1518#			      by the OpenSSL library.
1519#
1520#	   options=	Various SSL implementation options. The most important
1521#			being:
1522#			    NO_SSLv2    Disallow the use of SSLv2
1523#			    NO_SSLv3    Disallow the use of SSLv3
1524#			    NO_TLSv1    Disallow the use of TLSv1.0
1525#			    NO_TLSv1_1  Disallow the use of TLSv1.1
1526#			    NO_TLSv1_2  Disallow the use of TLSv1.2
1527#			    SINGLE_DH_USE Always create a new key when using
1528#				      temporary/ephemeral DH key exchanges
1529#			    ALL       Enable various bug workarounds
1530#				      suggested as "harmless" by OpenSSL
1531#				      Be warned that this reduces SSL/TLS
1532#				      strength to some attacks.
1533#			See OpenSSL SSL_CTX_set_options documentation for a
1534#			complete list of options.
1535#
1536#	   clientca=	File containing the list of CAs to use when
1537#			requesting a client certificate.
1538#
1539#	   cafile=	File containing additional CA certificates to
1540#			use when verifying client certificates. If unset
1541#			clientca will be used.
1542#
1543#	   capath=	Directory containing additional CA certificates
1544#			and CRL lists to use when verifying client certificates.
1545#
1546#	   crlfile=	File of additional CRL lists to use when verifying
1547#			the client certificate, in addition to CRLs stored in
1548#			the capath. Implies VERIFY_CRL flag below.
1549#
1550#	   dhparams=	File containing DH parameters for temporary/ephemeral
1551#			DH key exchanges. See OpenSSL documentation for details
1552#			on how to create this file.
1553#			WARNING: EDH ciphers will be silently disabled if this
1554#				 option is not set.
1555#
1556#	   sslflags=	Various flags modifying the use of SSL:
1557#			    DELAYED_AUTH
1558#				Don't request client certificates
1559#				immediately, but wait until acl processing
1560#				requires a certificate (not yet implemented).
1561#			    NO_DEFAULT_CA
1562#				Don't use the default CA lists built in
1563#				to OpenSSL.
1564#			    NO_SESSION_REUSE
1565#				Don't allow for session reuse. Each connection
1566#				will result in a new SSL session.
1567#			    VERIFY_CRL
1568#				Verify CRL lists when accepting client
1569#				certificates.
1570#			    VERIFY_CRL_ALL
1571#				Verify CRL lists for all certificates in the
1572#				client certificate chain.
1573#
1574#	   sslcontext=	SSL session ID context identifier.
1575#
1576#	Other Options:
1577#
1578#	   connection-auth[=on|off]
1579#	                use connection-auth=off to tell Squid to prevent 
1580#	                forwarding Microsoft connection oriented authentication
1581#			(NTLM, Negotiate and Kerberos)
1582#
1583#	   disable-pmtu-discovery=
1584#			Control Path-MTU discovery usage:
1585#			    off		lets OS decide on what to do (default).
1586#			    transparent	disable PMTU discovery when transparent
1587#					support is enabled.
1588#			    always	disable always PMTU discovery.
1589#
1590#			In many setups of transparently intercepting proxies
1591#			Path-MTU discovery can not work on traffic towards the
1592#			clients. This is the case when the intercepting device
1593#			does not fully track connections and fails to forward
1594#			ICMP must fragment messages to the cache server. If you
1595#			have such setup and experience that certain clients
1596#			sporadically hang or never complete requests set
1597#			disable-pmtu-discovery option to 'transparent'.
1598#
1599#	   name=	Specifies a internal name for the port. Defaults to
1600#			the port specification (port or addr:port)
1601#
1602#	   tcpkeepalive[=idle,interval,timeout]
1603#			Enable TCP keepalive probes of idle connections.
1604#			In seconds; idle is the initial time before TCP starts
1605#			probing the connection, interval how often to probe, and
1606#			timeout the time before giving up.
1607#
1608#	If you run Squid on a dual-homed machine with an internal
1609#	and an external interface we recommend you to specify the
1610#	internal address:port in http_port. This way Squid will only be
1611#	visible on the internal address.
1612#
1613#
1614
1615# Squid normally listens to port 3128
1616http_port 3128
1617
1618#  TAG: https_port
1619# Note: This option is only available if Squid is rebuilt with the
1620#       --enable-ssl
1621#
1622#	Usage:  [ip:]port cert=certificate.pem [key=key.pem] [mode] [options...]
1623#
1624#	The socket address where Squid will listen for client requests made
1625#	over TLS or SSL connections. Commonly referred to as HTTPS.
1626#
1627#	This is most useful for situations where you are running squid in
1628#	accelerator mode and you want to do the SSL work at the accelerator level.
1629#
1630#	You may specify multiple socket addresses on multiple lines,
1631#	each with their own SSL certificate and/or options.
1632#
1633#	Modes:
1634#
1635#	   accel	Accelerator / reverse proxy mode
1636#
1637#	   intercept	Support for IP-Layer interception of
1638#			outgoing requests without browser settings.
1639#			NP: disables authentication and IPv6 on the port.
1640#
1641#	   tproxy	Support Linux TPROXY for spoofing outgoing
1642#			connections using the client IP address.
1643#			NP: disables authentication and maybe IPv6 on the port.
1644#
1645#	   ssl-bump	For each intercepted connection allowed by ssl_bump
1646#			ACLs, establish a secure connection with the client and with
1647#			the server, decrypt HTTPS messages as they pass through
1648#			Squid, and treat them as unencrypted HTTP messages,
1649#			becoming the man-in-the-middle.
1650#
1651#			An "ssl_bump server-first" match is required to
1652#			fully enable bumping of intercepted SSL	connections.
1653#
1654#			Requires tproxy or intercept.
1655#
1656#	Omitting the mode flag causes default forward proxy mode to be used.
1657#
1658#
1659#	See http_port for a list of generic options
1660#
1661#
1662#	SSL Options:
1663#
1664#	   cert=	Path to SSL certificate (PEM format).
1665#
1666#	   key=		Path to SSL private key file (PEM format)
1667#			if not specified, the certificate file is
1668#			assumed to be a combined certificate and
1669#			key file.
1670#
1671#	   version=	The version of SSL/TLS supported
1672#			    1	automatic (default)
1673#			    2	SSLv2 only
1674#			    3	SSLv3 only
1675#			    4	TLSv1 only
1676#
1677#	   cipher=	Colon separated list of supported ciphers.
1678#
1679#	   options=	Various SSL engine options. The most important
1680#			being:
1681#			    NO_SSLv2  Disallow the use of SSLv2
1682#			    NO_SSLv3  Disallow the use of SSLv3
1683#			    NO_TLSv1  Disallow the use of TLSv1
1684#			    SINGLE_DH_USE Always create a new key when using
1685#				      temporary/ephemeral DH key exchanges
1686#			See src/ssl_support.c or OpenSSL SSL_CTX_set_options
1687#			documentation for a complete list of options.
1688#
1689#	   clientca=	File containing the list of CAs to use when
1690#			requesting a client certificate.
1691#
1692#	   cafile=	File containing additional CA certificates to
1693#			use when verifying client certificates. If unset
1694#			clientca will be used.
1695#
1696#	   capath=	Directory containing additional CA certificates
1697#			and CRL lists to use when verifying client certificates.
1698#
1699#	   crlfile=	File of additional CRL lists to use when verifying
1700#			the client certificate, in addition to CRLs stored in
1701#			the capath. Implies VERIFY_CRL flag below.
1702#
1703#	   dhparams=	File containing DH parameters for temporary/ephemeral
1704#			DH key exchanges.
1705#
1706#	   sslflags=	Various flags modifying the use of SSL:
1707#			    DELAYED_AUTH
1708#				Don't request client certificates
1709#				immediately, but wait until acl processing
1710#				requires a certificate (not yet implemented).
1711#			    NO_DEFAULT_CA
1712#				Don't use the default CA lists built in
1713#				to OpenSSL.
1714#			    NO_SESSION_REUSE
1715#				Don't allow for session reuse. Each connection
1716#				will result in a new SSL session.
1717#			    VERIFY_CRL
1718#				Verify CRL lists when accepting client
1719#				certificates.
1720#			    VERIFY_CRL_ALL
1721#				Verify CRL lists for all certificates in the
1722#				client certificate chain.
1723#
1724#	   sslcontext=	SSL session ID context identifier.
1725#
1726#	   generate-host-certificates[=<on|off>]
1727#			Dynamically create SSL server certificates for the
1728#			destination hosts of bumped SSL requests.When
1729#			enabled, the cert and key options are used to sign
1730#			generated certificates. Otherwise generated
1731#			certificate will be selfsigned.
1732#			If there is CA certificate life time of generated
1733#			certificate equals lifetime of CA certificate. If
1734#			generated certificate is selfsigned lifetime is three
1735#			years.
1736#			This option is enabled by default when SslBump is used.
1737#			See the sslBump option above for more information.
1738#
1739#	   dynamic_cert_mem_cache_size=SIZE
1740#			Approximate total RAM size spent on cached generated
1741#			certificates. If set to zero, caching is disabled. The
1742#			default value is 4MB.
1743#
1744#	See http_port for a list of available options.
1745#Default:
1746# none
1747
1748#  TAG: tcp_outgoing_tos
1749#	Allows you to select a TOS/Diffserv value for packets outgoing
1750#	on the server side, based on an ACL.
1751#
1752#	tcp_outgoing_tos ds-field [!]aclname ...
1753#
1754#	Example where normal_service_net uses the TOS value 0x00
1755#	and good_service_net uses 0x20
1756#
1757#	acl normal_service_net src 10.0.0.0/24
1758#	acl good_service_net src 10.0.1.0/24
1759#	tcp_outgoing_tos 0x00 normal_service_net
1760#	tcp_outgoing_tos 0x20 good_service_net
1761#
1762#	TOS/DSCP values really only have local significance - so you should
1763#	know what you're specifying. For more information, see RFC2474,
1764#	RFC2475, and RFC3260.
1765#
1766#	The TOS/DSCP byte must be exactly that - a octet value  0 - 255, or
1767#	"default" to use whatever default your host has. Note that in
1768#	practice often only multiples of 4 is usable as the two rightmost bits
1769#	have been redefined for use by ECN (RFC 3168 section 23.1).
1770#
1771#	Processing proceeds in the order specified, and stops at first fully
1772#	matching line.
1773#Default:
1774# none
1775
1776#  TAG: clientside_tos
1777#	Allows you to select a TOS/Diffserv value for packets being transmitted
1778#	on the client-side, based on an ACL.
1779#
1780#	clientside_tos ds-field [!]aclname ...
1781#
1782#	Example where normal_service_net uses the TOS value 0x00
1783#	and good_service_net uses 0x20
1784#
1785#	acl normal_service_net src 10.0.0.0/24
1786#	acl good_service_net src 10.0.1.0/24
1787#	clientside_tos 0x00 normal_service_net
1788#	clientside_tos 0x20 good_service_net
1789#
1790#	Note: This feature is incompatible with qos_flows. Any TOS values set here
1791#	will be overwritten by TOS values in qos_flows.
1792#Default:
1793# none
1794
1795#  TAG: tcp_outgoing_mark
1796# Note: This option is only available if Squid is rebuilt with the
1797#       Packet MARK (Linux)
1798#
1799#	Allows you to apply a Netfilter mark value to outgoing packets
1800#	on the server side, based on an ACL.
1801#
1802#	tcp_outgoing_mark mark-value [!]aclname ...
1803#
1804#	Example where normal_service_net uses the mark value 0x00
1805#	and good_service_net uses 0x20
1806#
1807#	acl normal_service_net src 10.0.0.0/24
1808#	acl good_service_net src 10.0.1.0/24
1809#	tcp_outgoing_mark 0x00 normal_service_net
1810#	tcp_outgoing_mark 0x20 good_service_net
1811#Default:
1812# none
1813
1814#  TAG: clientside_mark
1815# Note: This option is only available if Squid is rebuilt with the
1816#       Packet MARK (Linux)
1817#
1818#	Allows you to apply a Netfilter mark value to packets being transmitted
1819#	on the client-side, based on an ACL.
1820#
1821#	clientside_mark mark-value [!]aclname ...
1822#
1823#	Example where normal_service_net uses the mark value 0x00
1824#	and good_service_net uses 0x20
1825#
1826#	acl normal_service_net src 10.0.0.0/24
1827#	acl good_service_net src 10.0.1.0/24
1828#	clientside_mark 0x00 normal_service_net
1829#	clientside_mark 0x20 good_service_net
1830#
1831#	Note: This feature is incompatible with qos_flows. Any mark values set here
1832#	will be overwritten by mark values in qos_flows.
1833#Default:
1834# none
1835
1836#  TAG: qos_flows
1837#	Allows you to select a TOS/DSCP value to mark outgoing
1838#	connections to the client, based on where the reply was sourced.
1839#	For platforms using netfilter, allows you to set a netfilter mark
1840#	value instead of, or in addition to, a TOS value.
1841#
1842#	By default this functionality is disabled. To enable it with the default
1843#	settings simply use "qos_flows mark" or "qos_flows tos". Default
1844#	settings will result in the netfilter mark or TOS value being copied
1845#	from the upstream connection to the client. Note that it is the connection
1846#	CONNMARK value not the packet MARK value that is copied.
1847#
1848#	It is not currently possible to copy the mark or TOS value from the
1849#	client to the upstream connection request.
1850#
1851#	TOS values really only have local significance - so you should
1852#	know what you're specifying. For more information, see RFC2474,
1853#	RFC2475, and RFC3260.
1854#
1855#	The TOS/DSCP byte must be exactly that - a octet value  0 - 255. Note that
1856#	in practice often only multiples of 4 is usable as the two rightmost bits
1857#	have been redefined for use by ECN (RFC 3168 section 23.1).
1858#
1859#	Mark values can be any unsigned 32-bit integer value.
1860#
1861#	This setting is configured by setting the following values:
1862#
1863#	tos|mark                Whether to set TOS or netfilter mark values
1864#
1865#	local-hit=0xFF		Value to mark local cache hits.
1866#
1867#	sibling-hit=0xFF	Value to mark hits from sibling peers.
1868#
1869#	parent-hit=0xFF		Value to mark hits from parent peers.
1870#
1871#	miss=0xFF[/mask]	Value to mark cache misses. Takes precedence
1872#				over the preserve-miss feature (see below), unless
1873#				mask is specified, in which case only the bits
1874#				specified in the mask are written.
1875#
1876#	The TOS variant of the following features are only possible on Linux
1877#	and require your kernel to be patched with the TOS preserving ZPH
1878#	patch, available from http://zph.bratcheda.org
1879#	No patch is needed to preserve the netfilter mark, which will work
1880#	with all variants of netfilter.
1881#
1882#	disable-preserve-miss
1883#		This option disables the preservation of the TOS or netfilter
1884#		mark. By default, the existing TOS or netfilter mark value of
1885#		the response coming from the remote server will be retained
1886#		and masked with miss-mark.
1887#		NOTE: in the case of a netfilter mark, the mark must be set on
1888#		the connection (using the CONNMARK target) not on the packet
1889#		(MARK target).
1890#
1891#	miss-mask=0xFF
1892#		Allows you to mask certain bits in the TOS or mark value
1893#		received from the remote server, before copying the value to
1894#		the TOS sent towards clients.
1895#		Default for tos: 0xFF (TOS from server is not changed).
1896#		Default for mark: 0xFFFFFFFF (mark from server is not changed).
1897#
1898#	All of these features require the --enable-zph-qos compilation flag
1899#	(enabled by default). Netfilter marking also requires the
1900#	libnetfilter_conntrack libraries (--with-netfilter-conntrack) and
1901#	libcap 2.09+ (--with-libcap).
1902#
1903#Default:
1904# none
1905
1906#  TAG: tcp_outgoing_address
1907#	Allows you to map requests to different outgoing IP addresses
1908#	based on the username or source address of the user making
1909#	the request.
1910#
1911#	tcp_outgoing_address ipaddr [[!]aclname] ...
1912#
1913#	For example;
1914#		Forwarding clients with dedicated IPs for certain subnets.
1915#
1916#	  acl normal_service_net src 10.0.0.0/24
1917#	  acl good_service_net src 10.0.2.0/24
1918#
1919#	  tcp_outgoing_address 2001:db8::c001 good_service_net
1920#	  tcp_outgoing_address 10.1.0.2 good_service_net
1921#
1922#	  tcp_outgoing_address 2001:db8::beef normal_service_net
1923#	  tcp_outgoing_address 10.1.0.1 normal_service_net
1924#
1925#	  tcp_outgoing_address 2001:db8::1
1926#	  tcp_outgoing_address 10.1.0.3
1927#
1928#	Processing proceeds in the order specified, and stops at first fully
1929#	matching line.
1930#
1931#	Squid will add an implicit IP version test to each line.
1932#	Requests going to IPv4 websites will use the outgoing 10.1.0.* addresses.
1933#	Requests going to IPv6 websites will use the outgoing 2001:db8:* addresses.
1934#
1935#
1936#	NOTE: The use of this directive using client dependent ACLs is
1937#	incompatible with the use of server side persistent connections. To
1938#	ensure correct results it is best to set server_persistent_connections
1939#	to off when using this directive in such configurations.
1940#
1941#	NOTE: The use of this directive to set a local IP on outgoing TCP links
1942#	is incompatible with using TPROXY to set client IP out outbound TCP links.
1943#	When needing to contact peers use the no-tproxy cache_peer option and the
1944#	client_dst_passthru directive re-enable normal forwarding such as this.
1945#
1946#Default:
1947# Address selection is performed by the operating system.
1948
1949#  TAG: host_verify_strict
1950#	Regardless of this option setting, when dealing with intercepted
1951#	traffic, Squid always verifies that the destination IP address matches
1952#	the Host header domain or IP (called 'authority form URL').
1953#	
1954#	This enforcement is performed to satisfy a MUST-level requirement in
1955#	RFC 2616 section 14.23: "The Host field value MUST represent the naming
1956#	authority of the origin server or gateway given by the original URL".
1957#	
1958#	When set to ON:
1959#		Squid always responds with an HTTP 409 (Conflict) error
1960#		page and logs a security warning if there is no match.
1961#	
1962#		Squid verifies that the destination IP address matches
1963#		the Host header for forward-proxy and reverse-proxy traffic
1964#		as well. For those traffic types, Squid also enables the
1965#		following checks, comparing the corresponding Host header
1966#		and Request-URI components:
1967#	
1968#		 * The host names (domain or IP) must be identical,
1969#		   but valueless or missing Host header disables all checks.
1970#		   For the two host names to match, both must be either IP
1971#		   or FQDN.
1972#	
1973#		 * Port numbers must be identical, but if a port is missing
1974#		   the scheme-default port is assumed.
1975#	
1976#	
1977#	When set to OFF (the default):
1978#		Squid allows suspicious requests to continue but logs a
1979#		security warning and blocks caching of the response.
1980#	
1981#		 * Forward-proxy traffic is not checked at all.
1982#	
1983#		 * Reverse-proxy traffic is not checked at all.
1984#	
1985#		 * Intercepted traffic which passes verification is handled
1986#		   according to client_dst_passthru.
1987#	
1988#		 * Intercepted requests which fail verification are sent
1989#		   to the client original destination instead of DIRECT.
1990#		   This overrides 'client_dst_passthru off'.
1991#	
1992#		For now suspicious intercepted CONNECT requests are always
1993#		responded to with an HTTP 409 (Conflict) error page.
1994#	
1995#	
1996#	SECURITY NOTE:
1997#	
1998#	As described in CVE-2009-0801 when the Host: header alone is used
1999#	to determine the destination of a request it becomes trivial for
2000#	malicious scripts on remote websites to bypass browser same-origin
2001#	security policy and sandboxing protections.
2002#	
2003#	The cause of this is that such applets are allowed to perform their
2004#	own HTTP stack, in which case the same-origin policy of the browser
2005#	sandbox only verifies that the applet tries to contact the same IP
2006#	as from where it was loaded at the IP level. The Host: header may
2007#	be different from the connected IP and approved origin.
2008#	
2009#Default:
2010# host_verify_strict off
2011
2012#  TAG: client_dst_passthru
2013#	With NAT or TPROXY intercepted traffic Squid may pass the request
2014#	directly to the original client destination IP or seek a faster
2015#	source using the HTTP Host header.
2016#	
2017#	Using Host to locate alternative servers can provide faster
2018#	connectivity with a range of failure recovery options.
2019#	But can also lead to connectivity trouble when the client and
2020#	server are attempting stateful interactions unaware of the proxy.
2021#	
2022#	This option (on by default) prevents alternative DNS entries being
2023#	located to send intercepted traffic DIRECT to an origin server.
2024#	The clients original destination IP and port will be used instead.
2025#	
2026#	Regardless of this option setting, when dealing with intercepted
2027#	traffic Squid will verify the Host: header and any traffic which
2028#	fails Host verification will be treated as if this option were ON.
2029#	
2030#	see host_verify_strict for details on the verification process.
2031#Default:
2032# client_dst_passthru on
2033
2034# SSL OPTIONS
2035# -----------------------------------------------------------------------------
2036
2037#  TAG: ssl_unclean_shutdown
2038# Note: This option is only available if Squid is rebuilt with the
2039#       --enable-ssl
2040#
2041#	Some browsers (especially MSIE) bugs out on SSL shutdown
2042#	messages.
2043#Default:
2044# ssl_unclean_shutdown off
2045
2046#  TAG: ssl_engine
2047# Note: This option is only available if Squid is rebuilt with the
2048#       --enable-ssl
2049#
2050#	The OpenSSL engine to use. You will need to set this if you
2051#	would like to use hardware SSL acceleration for example.
2052#Default:
2053# none
2054
2055#  TAG: sslproxy_client_certificate
2056# Note: This option is only available if Squid is rebuilt with the
2057#       --enable-ssl
2058#
2059#	Client SSL Certificate to use when proxying https:// URLs
2060#Default:
2061# none
2062
2063#  TAG: sslproxy_client_key
2064# Note: This option is only available if Squid is rebuilt with the
2065#       --enable-ssl
2066#
2067#	Client SSL Key to use when proxying https:// URLs
2068#Default:
2069# none
2070
2071#  TAG: sslproxy_version
2072# Note: This option is only available if Squid is rebuilt with the
2073#       --enable-ssl
2074#
2075#	SSL version level to use when proxying https:// URLs
2076#
2077#	The versions of SSL/TLS supported:
2078#
2079#	    1	automatic (default)
2080#	    2	SSLv2 only
2081#	    3	SSLv3 only
2082#	    4	TLSv1.0 only
2083#	    5	TLSv1.1 only
2084#	    6	TLSv1.2 only
2085#Default:
2086# automatic SSL/TLS version negotiation
2087
2088#  TAG: sslproxy_options
2089# Note: This option is only available if Squid is rebuilt with the
2090#       --enable-ssl
2091#
2092#	SSL implementation options to use when proxying https:// URLs
2093#	
2094#	The most important being:
2095#
2096#	    NO_SSLv2    Disallow the use of SSLv2
2097#	    NO_SSLv3    Disallow the use of SSLv3
2098#	    NO_TLSv1    Disallow the use of TLSv1.0
2099#	    NO_TLSv1_1  Disallow the use of TLSv1.1
2100#	    NO_TLSv1_2  Disallow the use of TLSv1.2
2101#	    SINGLE_DH_USE
2102#		      Always create a new key when using temporary/ephemeral
2103#		      DH key exchanges
2104#	    SSL_OP_NO_TICKET
2105#		      Disable use of RFC5077 session tickets. Some servers
2106#		      may have problems understanding the TLS extension due
2107#		      to ambiguous specification in RFC4507.
2108#	    ALL       Enable various bug workarounds suggested as "harmless"
2109#		      by OpenSSL. Be warned that this may reduce SSL/TLS
2110#		      strength to some attacks.
2111#	
2112#	See the OpenSSL SSL_CTX_set_options documentation for a
2113#	complete list of possible options.
2114#Default:
2115# none
2116
2117#  TAG: sslproxy_cipher
2118# Note: This option is only available if Squid is rebuilt with the
2119#       --enable-ssl
2120#
2121#	SSL cipher list to use when proxying https:// URLs
2122#
2123#	Colon separated list of supported ciphers.
2124#Default:
2125# none
2126
2127#  TAG: sslproxy_cafile
2128# Note: This option is only available if Squid is rebuilt with the
2129#       --enable-ssl
2130#
2131#	file containing CA certificates to use when verifying server
2132#	certificates while proxying https:// URLs
2133#Default:
2134# none
2135
2136#  TAG: sslproxy_capath
2137# Note: This option is only available if Squid is rebuilt with the
2138#       --enable-ssl
2139#
2140#	directory containing CA certificates to use when verifying
2141#	server certificates while proxying https:// URLs
2142#Default:
2143# none
2144
2145#  TAG: ssl_bump
2146# Note: This option is only available if Squid is rebuilt with the
2147#       --enable-ssl
2148#
2149#	This option is consulted when a CONNECT request is received on
2150#	an http_port (or a new connection is intercepted at an
2151#	https_port), provided that port was configured with an ssl-bump
2152#	flag. The subsequent data on the connection is either treated as
2153#	HTTPS and decrypted OR tunneled at TCP level without decryption,
2154#	depending on the first bumping "mode" which ACLs match.
2155#
2156#	ssl_bump <mode> [!]acl ...
2157#
2158#	The following bumping modes are supported:
2159#
2160#	    client-first
2161#		Allow bumping of the connection. Establish a secure connection
2162#		with the client first, then connect to the server. This old mode
2163#		does not allow Squid to mimic server SSL certificate and does
2164#		not work with intercepted SSL connections.
2165#
2166#	    server-first
2167#		Allow bumping of the connection. Establish a secure connection
2168#		with the server first, then establish a secure connection with
2169#		the client, using a mimicked server certificate. Works with both
2170#		CONNECT requests and intercepted SSL connections.
2171#
2172#	    none
2173#		Become a TCP tunnel without decoding the connection.
2174#		Works with both CONNECT requests and intercepted SSL
2175#		connections. This is the default behavior when no
2176#		ssl_bump option is given or no ssl_bump ACLs match.
2177#
2178#	By default, no connections are bumped.
2179#
2180#	The first matching ssl_bump option wins. If no ACLs match, the
2181#	connection is not bumped. Unlike most allow/deny ACL lists, ssl_bump
2182#	does not have an implicit "negate the last given option" rule. You
2183#	must make that rule explicit if you convert old ssl_bump allow/deny
2184#	rules that rely on such an implicit rule.
2185#
2186#	This clause supports both fast and slow acl types.
2187#	See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
2188#
2189#	See also: http_port ssl-bump, https_port ssl-bump
2190#
2191#
2192#	# Example: Bump all requests except those originating from
2193#	# localhost or those going to example.com.
2194#
2195#	acl broken_sites dstdomain .example.com
2196#	ssl_bump none localhost
2197#	ssl_bump none broken_sites
2198#	ssl_bump server-first all
2199#Default:
2200# Does not bump unless rules are present in squid.conf
2201
2202#  TAG: sslproxy_flags
2203# Note: This option is only available if Squid is rebuilt with the
2204#       --enable-ssl
2205#
2206#	Various flags modifying the use of SSL while proxying https:// URLs:
2207#	    DONT_VERIFY_PEER	Accept certificates that fail verification.
2208#				For refined control, see sslproxy_cert_error.
2209#	    NO_DEFAULT_CA	Don't use the default CA list built in
2210#				to OpenSSL.
2211#Default:
2212# none
2213
2214#  TAG: sslproxy_cert_error
2215# Note: This option is only available if Squid is rebuilt with the
2216#       --enable-ssl
2217#
2218#	Use this ACL to bypass server certificate validation errors.
2219#
2220#	For example, the following lines will bypass all validation errors
2221#	when talking to servers for example.com. All other
2222#	validation errors will result in ERR_SECURE_CONNECT_FAIL error.
2223#
2224#		acl BrokenButTrustedServers dstdomain example.com
2225#		sslproxy_cert_error allow BrokenButTrustedServers
2226#		sslproxy_cert_error deny all
2227#
2228#	This clause only supports fast acl types.
2229#	See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
2230#	Using slow acl types may result in server crashes
2231#
2232#	Without this option, all server certificate validation errors
2233#	terminate the transaction to protect Squid and the client.
2234#
2235#	SQUID_X509_V_ERR_INFINITE_VALIDATION error cannot be bypassed
2236#	but should not happen unless your OpenSSL library is buggy.
2237#
2238#	SECURITY WARNING:
2239#		Bypassing validation errors is dangerous because an
2240#		error usually implies that the server cannot be trusted
2241#		and the connection may be insecure.
2242#
2243#	See also: sslproxy_flags and DONT_VERIFY_PEER.
2244#Default:
2245# Server certificate errors terminate the transaction.
2246
2247#  TAG: sslproxy_cert_sign
2248# Note: This option is only available if Squid is rebuilt with the
2249#       --enable-ssl
2250#
2251#
2252#        sslproxy_cert_sign <signing algorithm> acl ...
2253#
2254#        The following certificate signing algorithms are supported:
2255#
2256#	   signTrusted
2257#		Sign using the configured CA certificate which is usually
2258#		placed in and trusted by end-user browsers. This is the
2259#		default for trusted origin server certificates.
2260#
2261#	   signUntrusted
2262#		Sign to guarantee an X509_V_ERR_CERT_UNTRUSTED browser error.
2263#		This is the default for untrusted origin server certificates
2264#		that are not self-signed (see ssl::certUntrusted).
2265#
2266#	   signSelf
2267#		Sign using a self-signed certificate with the right CN to
2268#		generate a X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT error in the
2269#		browser. This is the default for self-signed origin server
2270#		certificates (see ssl::certSelfSigned).
2271#
2272#	This clause only supports fast acl types.
2273#
2274#	When sslproxy_cert_sign acl(s) match, Squid uses the corresponding
2275#	signing algorithm to generate the certificate and ignores all
2276#	subsequent sslproxy_cert_sign options (the first match wins). If no
2277#	acl(s) match, the default signing algorithm is determined by errors
2278#	detected when obtaining and validating the origin server certificate.
2279#
2280#	WARNING: SQUID_X509_V_ERR_DOMAIN_MISMATCH and ssl:certDomainMismatch can
2281#	be used with sslproxy_cert_adapt, but if and only if Squid is bumping a
2282#	CONNECT request that carries a domain name. In all other cases (CONNECT
2283#	to an IP address or an intercepted SSL connection), Squid cannot detect
2284#	the domain mismatch at certificate generation time when
2285#	bump-server-first is used.
2286#Default:
2287# none
2288
2289#  TAG: sslproxy_cert_adapt
2290# Note: This option is only available if Squid is rebuilt with the
2291#       --enable-ssl
2292#
2293#	
2294#	sslproxy_cert_adapt <adaptation algorithm> acl ...
2295#
2296#	The following certificate adaptation algorithms are supported:
2297#
2298#	   setValidAfter
2299#		Sets the "Not After" property to the "Not After" property of
2300#		the CA certificate used to sign generated certificates.
2301#
2302#	   setValidBefore
2303#		Sets the "Not Before" property to the "Not Before" property of
2304#		the CA certificate used to sign generated certificates.
2305#
2306#	   setCommonName or setCommonName{CN}
2307#		Sets Subject.CN property to the host name specified as a 
2308#		CN parameter or, if no explicit CN parameter was specified,
2309#		extracted from the CONNECT request. It is a misconfiguration
2310#		to use setCommonName without an explicit parameter for
2311#		intercepted or tproxied SSL connections.
2312#		
2313#	This clause only supports fast acl types.
2314#
2315#	Squid first groups sslproxy_cert_adapt options by adaptation algorithm.
2316#	Within a group, when sslproxy_cert_adapt acl(s) match, Squid uses the
2317#	corresponding adaptation algorithm to generate the certificate and
2318#	ignores all subsequent sslproxy_cert_adapt options in that algorithm's
2319#	group (i.e., the first match wins within each algorithm group). If no
2320#	acl(s) match, the default mimicking action takes place.
2321#
2322#	WARNING: SQUID_X509_V_ERR_DOMAIN_MISMATCH and ssl:certDomainMismatch can
2323#	be used with sslproxy_cert_adapt, but if and only if Squid is bumping a
2324#	CONNECT request that carries a domain name. In all other cases (CONNECT
2325#	to an IP address or an intercepted SSL connection), Squid cannot detect
2326#	the domain mismatch at certificate generation time when
2327#	bump-server-first is used.
2328#Default:
2329# none
2330
2331#  TAG: sslpassword_program
2332# Note: This option is only available if Squid is rebuilt with the
2333#       --enable-ssl
2334#
2335#	Specify a program used for entering SSL key passphrases
2336#	when using encrypted SSL certificate keys. If not specified
2337#	keys must either be unencrypted, or Squid started with the -N
2338#	option to allow it to query interactively for the passphrase.
2339#
2340#	The key file name is given as argument to the program allowing
2341#	selection of the right password if you have multiple encrypted
2342#	keys.
2343#Default:
2344# none
2345
2346# OPTIONS RELATING TO EXTERNAL SSL_CRTD 
2347# -----------------------------------------------------------------------------
2348
2349#  TAG: sslcrtd_program
2350# Note: This option is only available if Squid is rebuilt with the
2351#       --enable-ssl-crtd
2352#
2353#	Specify the location and options of the executable for ssl_crtd process.
2354#	/usr/lib/squid3/ssl_crtd program requires -s and -M parameters
2355#	For more information use:
2356#		/usr/lib/squid3/ssl_crtd -h
2357#Default:
2358# sslcrtd_program /usr/lib/squid3/ssl_crtd -s /var/lib/ssl_db -M 4MB
2359
2360#  TAG: sslcrtd_children
2361# Note: This option is only available if Squid is rebuilt with the
2362#       --enable-ssl-crtd
2363#
2364#	The maximum number of processes spawn to service ssl server.
2365#	The maximum this may be safely set to is 32.
2366#	
2367#	The startup= and idle= options allow some measure of skew in your
2368#	tuning.
2369#	
2370#		startup=N
2371#	
2372#	Sets the minimum number of processes to spawn when Squid
2373#	starts or reconfigures. When set to zero the first request will
2374#	cause spawning of the first child process to handle it.
2375#	
2376#	Starting too few children temporary slows Squid under load while it
2377#	tries to spawn enough additional processes to cope with traffic.
2378#	
2379#		idle=N
2380#	
2381#	Sets a minimum of how many processes Squid is to try and keep available
2382#	at all times. When traffic begins to rise above what the existing
2383#	processes can handle this many more will be spawned up to the maximum
2384#	configured. A minimum setting of 1 is required.
2385#	
2386#	You must have at least one ssl_crtd process.
2387#Default:
2388# sslcrtd_children 32 startup=5 idle=1
2389
2390#  TAG: sslcrtvalidator_program
2391# Note: This option is only available if Squid is rebuilt with the
2392#       --enable-ssl
2393#
2394#	Specify the location and options of the executable for ssl_crt_validator
2395#	process.
2396#
2397#	Usage:  sslcrtvalidator_program [ttl=n] [cache=n] path ...
2398#
2399#	Options:
2400#	  ttl=n         TTL in seconds for cached results. The default is 60 secs
2401#	  cache=n       limit the result cache size. The default value is 2048
2402#Default:
2403# none
2404
2405#  TAG: sslcrtvalidator_children
2406# Note: This option is only available if Squid is rebuilt with the
2407#       --enable-ssl
2408#
2409#	The maximum number of processes spawn to service SSL server.
2410#	The maximum this may be safely set to is 32.
2411#	
2412#	The startup= and idle= options allow some measure of skew in your
2413#	tuning.
2414#	
2415#		startup=N
2416#	
2417#	Sets the minimum number of processes to spawn when Squid
2418#	starts or reconfigures. When set to zero the first request will
2419#	cause spawning of the first child process to handle it.
2420#	
2421#	Starting too few children temporary slows Squid under load while it
2422#	tries to spawn enough additional processes to cope with traffic.
2423#	
2424#		idle=N
2425#	
2426#	Sets a minimum of how many processes Squid is to try and keep available
2427#	at all times. When traffic begins to rise above what the existing
2428#	processes can handle this many more will be spawned up to the maximum
2429#	configured. A minimum setting of 1 is required.
2430#
2431#		concurrency=
2432#	
2433#	The number of requests each certificate validator helper can handle in
2434#	parallel. A value of 0 indicates the certficate validator does not
2435#	support concurrency. Defaults to 1.
2436#	
2437#	When this directive is set to a value >= 1 then the protocol
2438#	used to communicate with the helper is modified to include
2439#	a request ID in front of the request/response. The request
2440#	ID from the request must be echoed back with the response
2441#	to that request.
2442#	
2443#	You must have at least one ssl_crt_validator process.
2444#Default:
2445# sslcrtvalidator_children 32 startup=5 idle=1 concurrency=1
2446
2447# OPTIONS WHICH AFFECT THE NEIGHBOR SELECTION ALGORITHM
2448# -----------------------------------------------------------------------------
2449
2450#  TAG: cache_peer
2451#	To specify other caches in a hierarchy, use the format:
2452#	
2453#		cache_peer hostname type http-port icp-port [options]
2454#	
2455#	For example,
2456#	
2457#	#                                        proxy  icp
2458#	#          hostname             type     port   port  options
2459#	#          -------------------- -------- ----- -----  -----------
2460#	cache_peer parent.foo.net       parent    3128  3130  default
2461#	cache_peer sib1.foo.net         sibling   3128  3130  proxy-only
2462#	cache_peer sib2.foo.net         sibling   3128  3130  proxy-only
2463#	cache_peer example.com          parent    80       0  default
2464#	cache_peer cdn.example.com      sibling   3128     0  
2465#	
2466#	      type:	either 'parent', 'sibling', or 'multicast'.
2467#	
2468#	proxy-port:	The port number where the peer accept HTTP requests.
2469#			For other Squid proxies this is usually 3128
2470#			For web servers this is usually 80
2471#	
2472#	  icp-port:	Used for querying neighbor caches about objects.
2473#			Set to 0 if the peer does not support ICP or HTCP.
2474#			See ICP and HTCP options below for additional details.
2475#	
2476#	
2477#	==== ICP OPTIONS ====
2478#	
2479#	You MUST also set icp_port and icp_access explicitly when using these options.
2480#	The defaults will prevent peer traffic using ICP.
2481#	
2482#	
2483#	no-query	Disable ICP queries to this neighbor.
2484#	
2485#	multicast-responder
2486#			Indicates the named peer is a member of a multicast group.
2487#			ICP queries will not be sent directly to the peer, but ICP
2488#			replies will be accepted from it.
2489#	
2490#	closest-only	Indicates that, for ICP_OP_MISS replies, we'll only forward
2491#			CLOSEST_PARENT_MISSes and never FIRST_PARENT_MISSes.
2492#	
2493#	background-ping
2494#			To only send ICP queries to this neighbor infrequently.
2495#			This is used to keep the neighbor round trip time updated
2496#			and is usually used in conjunction with weighted-round-robin.
2497#	
2498#	
2499#	==== HTCP OPTIONS ====
2500#	
2501#	You MUST also set htcp_port and htcp_access explicitly when using these options.
2502#	The defaults will prevent peer traffic using HTCP.
2503#	
2504#	
2505#	htcp		Send HTCP, instead of ICP, queries to the neighbor.
2506#			You probably also want to set the "icp-port" to 4827
2507#			instead of 3130. This directive accepts a comma separated
2508#			list of options described below.
2509#	
2510#	htcp=oldsquid	Send HTCP to old Squid versions (2.5 or earlier).
2511#	
2512#	htcp=no-clr	Send HTCP to the neighbor but without
2513#			sending any CLR requests.  This cannot be used with
2514#			only-clr.
2515#	
2516#	htcp=only-clr	Send HTCP to the neighbor but ONLY CLR requests.
2517#			This cannot be used with no-clr.
2518#	
2519#	htcp=no-purge-clr
2520#			Send HTCP to the neighbor including CLRs but only when
2521#			they do not result from PURGE requests.
2522#	
2523#	htcp=forward-clr
2524#			Forward any HTCP CLR requests this proxy receives to the peer.
2525#	
2526#	
2527#	==== PEER SELECTION METHODS ====
2528#	
2529#	The default peer selection method is ICP, with the first responding peer
2530#	being used as source. These options can be used for better load balancing.
2531#	
2532#	
2533#	default		This is a parent cache which can be used as a "last-resort"
2534#			if a peer cannot be located by any of the peer-selection methods.
2535#			If specified more than once, only the first is used.
2536#	
2537#	round-robin	Load-Balance parents which should be used in a round-robin
2538#			fashion in the absence of any ICP queries.
2539#			weight=N can be used to add bias.
2540#	
2541#	weighted-round-robin
2542#			Load-Balance parents which should be used in a round-robin
2543#			fashion with the frequency of each parent being based on the
2544#			round trip time. Closer parents are used more often.
2545#			Usually used for background-ping parents.
2546#			weight=N can be used to add bias.
2547#	
2548#	carp		Load-Balance parents which should be used as a CARP array.
2549#			The requests will be distributed among the parents based on the
2550#			CARP load balancing hash function based on their weight.
2551#	
2552#	userhash	Load-balance parents based on the client proxy_auth or ident username.
2553#	
2554#	sourcehash	Load-balance parents based on the client source IP.
2555#
2556#	multicast-siblings
2557#			To be used only for cache peers of type "multicast".
2558#			ALL members of this multicast group have "sibling"
2559#			relationship with it, not "parent".  This is to a multicast
2560#			group when the requested object would be fetched only from
2561#			a "parent" cache, anyway.  It's useful, e.g., when
2562#			configuring a pool of redundant Squid proxies, being
2563#			members of the same multicast group.
2564#	
2565#	
2566#	==== PEER SELECTION OPTIONS ====
2567#	
2568#	weight=N	use to affect the selection of a peer during any weighted
2569#			peer-selection mechanisms.
2570#			The weight must be an integer; default is 1,
2571#			larger weights are favored more.
2572#			This option does not affect parent selection if a peering
2573#			protocol is not in use.
2574#	
2575#	basetime=N	Specify a base amount to be subtracted from round trip
2576#			times of parents.
2577#			It is subtracted before division by weight in calculating
2578#			which parent to fectch from. If the rtt is less than the
2579#			base time the rtt is set to a minimal value.
2580#	
2581#	ttl=N		Specify a TTL to use when sending multicast ICP queries
2582#			to this address.
2583#			Only useful when sending to a multicast group.
2584#			Because we don't accept ICP replies from random
2585#			hosts, you must configure other group members as
2586#			peers with the 'multicast-responder' option.
2587#	
2588#	no-delay	To prevent access to this neighbor from influencing the
2589#			delay pools.
2590#	
2591#	digest-url=URL	Tell Squid to fetch the cache digest (if digests are
2592#			enabled) for this host from the specified URL rather
2593#			than the Squid default location.
2594#	
2595#	
2596#	==== CARP OPTIONS ====
2597#	
2598#	carp-key=key-specification
2599#			use a different key than the full URL to hash against the peer.
2600#			the key-specification is a comma-separated list of the keywords			
2601#			scheme, host, port, path, params
2602#			Order is not important.
2603#	
2604#	==== ACCELERATOR / REVERSE-PROXY OPTIONS ====
2605#	
2606#	originserver	Causes this parent to be contacted as an origin server.
2607#			Meant to be used in accelerator setups when the peer
2608#			is a web server.
2609#	
2610#	forceddomain=name
2611#			Set the Host header of requests forwarded to this peer.
2612#			Useful in accelerator setups where the server (peer)
2613#			expects a certain domain name but clients may request
2614#			others. ie example.com or www.example.com
2615#	
2616#	no-digest	Disable request of cache digests.
2617#	
2618#	no-netdb-exchange
2619#			Disables requesting ICMP RTT database (NetDB).
2620#	
2621#	
2622#	==== AUTHENTICATION OPTIONS ====
2623#	
2624#	login=user:password
2625#			If this is a personal/workgroup proxy and your parent
2626#			requires proxy authentication.
2627#			
2628#			Note: The string can include URL escapes (i.e. %20 for
2629#			spaces). This also means % must be written as %%.
2630#	
2631#	login=PASSTHRU
2632#			Send login details received from client to this peer.
2633#			Both Proxy- and WWW-Authorization headers are passed
2634#			without alteration to the peer.
2635#			Authentication is not required by Squid for this to work.
2636#			
2637#			Note: This will pass any form of authentication but
2638#			only Basic auth will work through a proxy unless the
2639#			connection-auth options are also used.
2640#
2641#	login=PASS	Send login details received from client to this peer.
2642#			Authentication is not required by this option.
2643#			
2644#			If there are no client-provided authentication headers
2645#			to pass on, but username and password are available
2646#			from an external ACL user= and password= result tags
2647#			they may be sent instead.
2648#			
2649#			Note: To combine this with proxy_auth both proxies must
2650#			share the same user database as HTTP only allows for
2651#			a single login (one for proxy, one for origin server).
2652#			Also be warned this will expose your users proxy
2653#			password to the peer. USE WITH CAUTION
2654#	
2655#	login=*:password
2656#			Send the username to the upstream cache, but with a
2657#			fixed password. This is meant to be used when the peer
2658#			is in another administrative domain, but it is still
2659#			needed to identify each user.
2660#			The star can optionally be followed by some extra
2661#			information which is added to the username. This can
2662#			be used to identify this proxy to the peer, similar to
2663#			the login=username:password option above.
2664#	
2665#	login=NEGOTIATE
2666#			If this is a personal/workgroup proxy and your parent
2667#			requires a secure proxy authentication.
2668#			The first principal from the default keytab or defined by
2669#			the environment variable KRB5_KTNAME will be used. 
2670#	
2671#			WARNING: The connection may transmit requests from multiple
2672#			clients. Negotiate often assumes end-to-end authentication
2673#			and a single-client. Which is not strictly true here.
2674#	
2675#	login=NEGOTIATE:principal_name
2676#			If this is a personal/workgroup proxy and your parent
2677#			requires a secure proxy authentication. 
2678#			The principal principal_name from the default keytab or
2679#			defined by the environment variable KRB5_KTNAME will be
2680#			used.
2681#	
2682#			WARNING: The connection may transmit requests from multiple
2683#			clients. Negotiate often assumes end-to-end authentication
2684#			and a single-client. Which is not strictly true here.
2685#	
2686#	connection-auth=on|off
2687#			Tell Squid that this peer does or not support Microsoft
2688#			connection oriented authentication, and any such
2689#			challenges received from there should be ignored.
2690#			Default is auto to automatically determine the status
2691#			of the peer.
2692#	
2693#	
2694#	==== SSL / HTTPS / TLS OPTIONS ====
2695#	
2696#	ssl		Encrypt connections to this peer with SSL/TLS.
2697#	
2698#	sslcert=/path/to/ssl/certificate
2699#			A client SSL certificate to use when connecting to
2700#			this peer.
2701#	
2702#	sslkey=/path/to/ssl/key
2703#			The private SSL key corresponding to sslcert above.
2704#			If 'sslkey' is not specified 'sslcert' is assumed to
2705#			reference a combined file containing both the
2706#			certificate and the key.
2707#	
2708#	sslversion=1|2|3|4|5|6
2709#			The SSL version to use when connecting to this peer
2710#				1 = automatic (default)
2711#				2 = SSL v2 only
2712#				3 = SSL v3 only
2713#				4 = TLS v1.0 only
2714#				5 = TLS v1.1 only
2715#				6 = TLS v1.2 only
2716#	
2717#	sslcipher=...	The list of valid SSL ciphers to use when connecting
2718#			to this peer.
2719#	
2720#	ssloptions=... 	Specify various SSL implementation options:
2721#
2722#			    NO_SSLv2    Disallow the use of SSLv2
2723#			    NO_SSLv3    Disallow the use of SSLv3
2724#			    NO_TLSv1    Disallow the use of TLSv1.0
2725#			    NO_TLSv1_1  Disallow the use of TLSv1.1
2726#			    NO_TLSv1_2  Disallow the use of TLSv1.2
2727#			    SINGLE_DH_USE
2728#				      Always create a new key when using
2729#				      temporary/ephemeral DH key exchanges
2730#			    ALL       Enable various bug workarounds
2731#				      suggested as "harmless" by OpenSSL
2732#				      Be warned that this reduces SSL/TLS
2733#				      strength to some attacks.
2734#
2735#			See the OpenSSL SSL_CTX_set_options documentation for a
2736#			more complete list.
2737#	
2738#	sslcafile=... 	A file containing additional CA certificates to use
2739#			when verifying the peer certificate.
2740#	
2741#	sslcapath=...	A directory containing additional CA certificates to
2742#			use when verifying the peer certificate.
2743#	
2744#	sslcrlfile=... 	A certificate revocation list file to use when
2745#			verifying the peer certificate.
2746#	
2747#	sslflags=...	Specify various flags modifying the SSL implementation:
2748#	
2749#			DONT_VERIFY_PEER
2750#				Accept certificates even if they fail to
2751#				verify.
2752#			NO_DEFAULT_CA
2753#				Don't use the default CA list built in
2754#				to OpenSSL.
2755#			DONT_VERIFY_DOMAIN
2756#				Don't verify the peer certificate
2757#				matches the server name
2758#	
2759#	ssldomain= 	The peer name as advertised in it's certificate.
2760#			Used for verifying the correctness of the received peer
2761#			certificate. If not specified the peer hostname will be
2762#			used.
2763#	
2764#	front-end-https
2765#			Enable the "Front-End-Https: On" header needed when
2766#			using Squid as a SSL frontend in front of Microsoft OWA.
2767#			See MS KB document Q307347 for details on this header.
2768#			If set to auto the header will only be added if the
2769#			request is forwarded as a https:// URL.
2770#	
2771#	
2772#	==== GENERAL OPTIONS ====
2773#	
2774#	connect-timeout=N
2775#			A peer-specific connect timeout.
2776#			Also see the peer_connect_timeout directive.
2777#	
2778#	connect-fail-limit=N
2779#			How many times connecting to a peer must fail before
2780#			it is marked as down. Default is 10.
2781#	
2782#	allow-miss	Disable Squid's use of only-if-cached when forwarding
2783#			requests to siblings. This is primarily useful when
2784#			icp_hit_stale is used by the sibling. To extensive use
2785#			of this option may result in forwarding loops, and you
2786#			should avoid having two-way peerings with this option.
2787#			For example to deny peer usage on requests from peer
2788#			by denying cache_peer_access if the source is a peer.
2789#	
2790#	max-conn=N	Limit the amount of connections Squid may open to this
2791#			peer. see also 
2792#	
2793#	name=xxx	Unique name for the peer.
2794#			Required if you have multiple peers on the same host
2795#			but different ports.
2796#			This name can be used in cache_peer_access and similar
2797#			directives to dentify the peer.
2798#			Can be used by outgoing access controls through the
2799#			peername ACL type.
2800#	
2801#	no-tproxy	Do not use the client-spoof TPROXY support when forwarding
2802#			requests to this peer. Use normal address selection instead.
2803#			This overrides the spoof_client_ip ACL.
2804#	
2805#	proxy-only	objects fetched from the peer will not be stored locally.
2806#	
2807#Default:
2808# none
2809
2810#  TAG: cache_peer_domain
2811#	Use to limit the domains for which a neighbor cache will be
2812#	queried.
2813#
2814#	Usage:
2815#		cache_peer_domain cache-host domain [domain ...]
2816#		cache_peer_domain cache-host !domain
2817#
2818#	For example, specifying
2819#
2820#		cache_peer_domain parent.foo.net	.edu
2821#
2822#	has the effect such that UDP query packets are sent to
2823#	'bigserver' only when the requested object exists on a
2824#	server in the .edu domain.  Prefixing the domainname
2825#	with '!' means the cache will be queried for objects
2826#	NOT in that domain.
2827#
2828#	NOTE:	* Any number of domains may be given for a cache-host,
2829#		  either on the same or separate lines.
2830#		* When multiple domains are given for a particular
2831#		  cache-host, the first matched domain is applied.
2832#		* Cache hosts with no domain restrictions are queried
2833#		  for all requests.
2834#		* There are no defaults.
2835#		* There is also a 'cache_peer_access' tag in the ACL
2836#		  section.
2837#Default:
2838# none
2839
2840#  TAG: cache_peer_access
2841#	Similar to 'cache_peer_domain' but provides more flexibility by
2842#	using ACL elements.
2843#
2844#	Usage:
2845#		cache_peer_access cache-host allow|deny [!]aclname ...
2846#
2847#	The syntax is identical to 'http_access' and the other lists of
2848#	ACL elements.  See the comments for 'http_access' below, or
2849#	the Squid FAQ (http://wiki.squid-cache.org/SquidFaq/SquidAcl).
2850#Default:
2851# none
2852
2853#  TAG: neighbor_type_domain
2854#	Modify the cache_peer neighbor type when passing requests
2855#	about specific domains to the peer.
2856#
2857#	Usage:
2858#		 neighbor_type_domain neighbor parent|sibling domain domain ...
2859#
2860#	For example:
2861#		cache_peer foo.example.com parent 3128 3130
2862#		neighbor_type_domain foo.example.com sibling .au .de
2863#
2864#	The above configuration treats all requests to foo.example.com as a
2865#	parent proxy unless the request is for a .au or .de ccTLD domain name.
2866#Default:
2867# The peer type from cache_peer directive is used for all requests to that peer.
2868
2869#  TAG: dead_peer_timeout	(seconds)
2870#	This controls how long Squid waits to declare a peer cache
2871#	as "dead."  If there are no ICP replies received in this
2872#	amount of time, Squid will declare the peer dead and not
2873#	expect to receive any further ICP replies.  However, it
2874#	continues to send ICP queries, and will mark the peer as
2875#	alive upon receipt of the first subsequent ICP reply.
2876#
2877#	This timeout also affects when Squid expects to receive ICP
2878#	replies from peers.  If more than 'dead_peer' seconds have
2879#	passed since the last ICP reply was received, Squid will not
2880#	expect to receive an ICP reply on the next query.  Thus, if
2881#	your time between requests is greater than this timeout, you
2882#	will see a lot of requests sent DIRECT to origin servers
2883#	instead of to your parents.
2884#Default:
2885# dead_peer_timeout 10 seconds
2886
2887#  TAG: forward_max_tries
2888#	Controls how many different forward paths Squid will try
2889#	before giving up. See also forward_timeout.
2890#	
2891#	NOTE: connect_retries (default: none) can make each of these
2892#	possible forwarding paths be tried multiple times.
2893#Default:
2894# forward_max_tries 10
2895
2896#  TAG: hierarchy_stoplist
2897#	A list of words which, if found in a URL, cause the object to
2898#	be handled directly by this cache.  In other words, use this
2899#	to not query neighbor caches for certain objects.  You may
2900#	list this option multiple times.
2901#
2902#	Example:
2903#		hierarchy_stoplist cgi-bin ?
2904#
2905#	Note: never_direct overrides this option.
2906#Default:
2907# none
2908
2909# MEMORY CACHE OPTIONS
2910# -----------------------------------------------------------------------------
2911
2912#  TAG: cache_mem	(bytes)
2913#	NOTE: THIS PARAMETER DOES NOT SPECIFY THE MAXIMUM PROCESS SIZE.
2914#	IT ONLY PLACES A LIMIT ON HOW MUCH ADDITIONAL MEMORY SQUID WILL
2915#	USE AS A MEMORY CACHE OF OBJECTS. SQUID USES MEMORY FOR OTHER
2916#	THINGS AS WELL. SEE THE SQUID FAQ SECTION 8 FOR DETAILS.
2917#
2918#	'cache_mem' specifies the ideal amount of memory to be used
2919#	for:
2920#		* In-Transit objects
2921#		* Hot Objects
2922#		* Negative-Cached objects
2923#
2924#	Data for these objects are stored in 4 KB blocks.  This
2925#	parameter specifies the ideal upper limit on the total size of
2926#	4 KB blocks allocated.  In-Transit objects take the highest
2927#	priority.
2928#
2929#	In-transit objects have priority over the others.  When
2930#	additional space is needed for incoming data, negative-cached
2931#	and hot objects will be released.  In other words, the
2932#	negative-cached and hot objects will fill up any unused space
2933#	not needed for in-transit objects.
2934#
2935#	If circumstances require, this limit will be exceeded.
2936#	Specifically, if your incoming request rate requires more than
2937#	'cache_mem' of memory to hold in-transit objects, Squid will
2938#	exceed this limit to satisfy the new requests.  When the load
2939#	decreases, blocks will be freed until the high-water mark is
2940#	reached.  Thereafter, blocks will be used to store hot
2941#	objects.
2942#
2943#	If shared memory caching is enabled, Squid does not use the shared
2944#	cache space for in-transit objects, but they still consume as much
2945#	local memory as they need. For more details about the shared memory
2946#	cache, see memory_cache_shared.
2947#Default:
2948# cache_mem 256 MB
2949
2950#  TAG: maximum_object_size_in_memory	(bytes)
2951#	Objects greater than this size will not be attempted to kept in
2952#	the memory cache. This should be set high enough to keep objects
2953#	accessed frequently in memory to improve performance whilst low
2954#	enough to keep larger objects from hoarding cache_mem.
2955#Default:
2956# maximum_object_size_in_memory 512 KB
2957
2958#  TAG: memory_cache_shared	on|off
2959#	Controls whether the memory cache is shared among SMP workers.
2960#
2961#	The shared memory cache is meant to occupy cache_mem bytes and replace
2962#	the non-shared memory cache, although some entities may still be
2963#	cached locally by workers for now (e.g., internal and in-transit
2964#	objects may be served from a local memory cache even if shared memory
2965#	caching is enabled).
2966#
2967#	By default, the memory cache is shared if and only if all of the
2968#	following conditions are satisfied: Squid runs in SMP mode with
2969#	multiple workers, cache_mem is positive, and Squid environment
2970#	supports required IPC primitives (e.g., POSIX shared memory segments
2971#	and GCC-style atomic operations).
2972#
2973#	To avoid blocking locks, shared memory uses opportunistic algorithms
2974#	that do not guarantee that every cachable entity that could have been
2975#	shared among SMP workers will actually be shared.
2976#
2977#	Currently, entities exceeding 32KB in size cannot be shared.
2978#Default:
2979# "on" where supported if doing memory caching with multiple SMP workers.
2980
2981#  TAG: memory_cache_mode
2982#	Controls which objects to keep in the memory cache (cache_mem)
2983#
2984#	always	Keep most recently fetched objects in memory (default)
2985#
2986#	disk	Only disk cache hits are kept in memory, which means
2987#		an object must first be cached on disk and then hit
2988#		a second time before cached in memory.
2989#
2990#	network	Only objects fetched from network is kept in memory
2991#Default:
2992# Keep the most recently fetched objects in memory
2993
2994#  TAG: memory_replacement_policy
2995#	The memory replacement policy parameter determines which
2996#	objects are purged from memory when memory space is needed.
2997#
2998#	See cache_replacement_policy for details on algorithms.
2999#Default:
3000# memory_replacement_policy lru
3001
3002# DISK CACHE OPTIONS
3003# -----------------------------------------------------------------------------
3004
3005#  TAG: cache_replacement_policy
3006#	The cache replacement policy parameter determines which
3007#	objects are evicted (replaced) when disk space is needed.
3008#
3009#	    lru       : Squid's original list based LRU policy
3010#	    heap GDSF : Greedy-Dual Size Frequency
3011#	    heap LFUDA: Least Frequently Used with Dynamic Aging
3012#	    heap LRU  : LRU policy implemented using a heap
3013#
3014#	Applies to any cache_dir lines listed below this directive.
3015#
3016#	The LRU policies keeps recently referenced objects.
3017#
3018#	The heap GDSF policy optimizes object hit rate by keeping smaller
3019#	popular objects in cache so it has a better chance of getting a
3020#	hit.  It achieves a lower byte hit rate than LFUDA though since
3021#	it evicts larger (possibly popular) objects.
3022#
3023#	The heap LFUDA policy keeps popular objects in cache regardless of
3024#	their size and thus optimizes byte hit rate at the expense of
3025#	hit rate since one large, popular object will prevent many
3026#	smaller, slightly less popular objects from being cached.
3027#
3028#	Both policies utilize a dynamic aging mechanism that prevents
3029#	cache pollution that can otherwise occur with frequency-based
3030#	replacement policies.
3031#
3032#	NOTE: if using the LFUDA replacement policy you should increase
3033#	the value of maximum_object_size above its default of 4 MB to
3034#	to maximize the potential byte hit rate improvement of LFUDA.
3035#
3036#	For more information about the GDSF and LFUDA cache replacement
3037#	policies see http://www.hpl.hp.com/techreports/1999/HPL-1999-69.html
3038#	and http://fog.hpl.external.hp.com/techreports/98/HPL-98-173.html.
3039#Default:
3040# cache_replacement_policy lru
3041
3042#  TAG: minimum_object_size	(bytes)
3043#	Objects smaller than this size will NOT be saved on disk.  The
3044#	value is specified in bytes, and the default is 0 KB, which
3045#	means all responses can be stored.
3046#Default:
3047# no limit
3048
3049#  TAG: maximum_object_size	(bytes)
3050#	Set the default value for max-size parameter on any cache_dir.
3051#	The value is specified in bytes, and the default is 4 MB.
3052#	
3053#	If you wish to get a high BYTES hit ratio, you should probably
3054#	increase this (one 32 MB object hit counts for 3200 10KB
3055#	hits).
3056#	
3057#	If you wish to increase hit ratio more than you want to
3058#	save bandwidth you should leave this low.
3059#	
3060#	NOTE: if using the LFUDA replacement policy you should increase
3061#	this value to maximize the byte hit rate improvement of LFUDA!
3062#	See cache_replacement_policy for a discussion of this policy.
3063#Default:
3064# maximum_object_size 4 MB
3065
3066#  TAG: cache_dir
3067#	Format:
3068#		cache_dir Type Directory-Name Fs-specific-data [options]
3069#
3070#	You can specify multiple cache_dir lines to spread the
3071#	cache among different disk partitions.
3072#
3073#	Type specifies the kind of storage system to use. Only "ufs"
3074#	is built by default. To enable any of the other storage systems
3075#	see the --enable-storeio configure option.
3076#
3077#	'Directory' is a top-level directory where cache swap
3078#	files will be stored.  If you want to use an entire disk
3079#	for caching, this can be the mount-point directory.
3080#	The directory must exist and be writable by the Squid
3081#	process.  Squid will NOT create this directory for you.
3082#
3083#	In SMP configurations, cache_dir must not precede the workers option
3084#	and should use configuration macros or conditionals to give each
3085#	worker interested in disk caching a dedicated cache directory.
3086#
3087#
3088#	====  The ufs store type  ====
3089#
3090#	"ufs" is the old well-known Squid storage format that has always
3091#	been there.
3092#
3093#	Usage:
3094#		cache_dir ufs Directory-Name Mbytes L1 L2 [options]
3095#
3096#	'Mbytes' is the amount of disk space (MB) to use under this
3097#	directory.  The default is 100 MB.  Change this to suit your
3098#	configuration.  Do NOT put the size of your disk drive here.
3099#	Instead, if you want Squid to use the entire disk drive,
3100#	subtract 20% and use that value.
3101#
3102#	'L1' is the number of first-level subdirectories which
3103#	will be created under the 'Directory'.  The default is 16.
3104#
3105#	'L2' is the number of second-level subdirectories which
3106#	will be created under each first-level directory.  The default
3107#	is 256.
3108#
3109#
3110#	====  The aufs store type  ====
3111#
3112#	"aufs" uses the same storage format as "ufs", utilizing
3113#	POSIX-threads to avoid blocking the main Squid process on
3114#	disk-I/O. This was formerly known in Squid as async-io.
3115#
3116#	Usage:
3117#		cache_dir aufs Directory-Name Mbytes L1 L2 [options]
3118#
3119#	see argument descriptions under ufs above
3120#
3121#
3122#	====  The diskd store type  ====
3123#
3124#	"diskd" uses the same storage format as "ufs", utilizing a
3125#	separate process to avoid blocking the main Squid process on
3126#	disk-I/O.
3127#
3128#	Usage:
3129#		cache_dir diskd Directory-Name Mbytes L1 L2 [options] [Q1=n] [Q2=n]
3130#
3131#	see argument descriptions under ufs above
3132#
3133#	Q1 specifies the number of unacknowledged I/O requests when Squid
3134#	stops opening new files. If this many messages are in the queues,
3135#	Squid won't open new files. Default is 64
3136#
3137#	Q2 specifies the number of unacknowledged messages when Squid
3138#	starts blocking.  If this many messages are in the queues,
3139#	Squid blocks until it receives some replies. Default is 72
3140#
3141#	When Q1 < Q2 (the default), the cache directory is optimized
3142#	for lower response time at the expense of a decrease in hit
3143#	ratio.  If Q1 > Q2, the cache directory is optimized for
3144#	higher hit ratio at the expense of an increase in response
3145#	time.
3146#
3147#
3148#	====  The rock store type  ====
3149#
3150#	Usage:
3151#	    cache_dir rock Directory-Name Mbytes <max-size=bytes> [options]
3152#
3153#	The Rock Store type is a database-style storage. All cached
3154#	entries are stored in a "database" file, using fixed-size slots,
3155#	one entry per slot. The database size is specified in MB. The
3156#	slot size is specified in bytes using the max-size option. See
3157#	below for more info on the max-size option.
3158#
3159#	If possible, Squid using Rock Store creates a dedicated kid
3160#	process called "disker" to avoid blocking Squid worker(s) on disk
3161#	I/O. One disker kid is created for each rock cache_dir.  Diskers
3162#	are created only when Squid, running in daemon mode, has support
3163#	for the IpcIo disk I/O module.
3164#
3165#	swap-timeout=msec: Squid will not start writing a miss to or
3166#	reading a hit from disk if it estimates that the swap operation
3167#	will take more than the specified number of milliseconds. By
3168#	default and when set to zero, disables the disk I/O time limit
3169#	enforcement. Ignored when using blocking I/O module because
3170#	blocking synchronous I/O does not allow Squid to estimate the
3171#	expected swap wait time.
3172#
3173#	max-swap-rate=swaps/sec: Artificially limits disk access using
3174#	the specified I/O rate limit. Swap out requests that
3175#	would cause the average I/O rate to exceed the limit are
3176#	delayed. Individual swap in requests (i.e., hits or reads) are
3177#	not delayed, but they do contribute to measured swap rate and
3178#	since they are placed in the same FIFO queue as swap out
3179#	requests, they may wait longer if max-swap-rate is smaller.
3180#	This is necessary on file systems that buffer "too
3181#	many" writes and then start blocking Squid and other processes
3182#	while committing those writes to disk.  Usually used together
3183#	with swap-timeout to avoid excessive delays and queue overflows
3184#	when disk demand exceeds available disk "bandwidth". By default
3185#	and when set to zero, disables the disk I/O rate limit
3186#	enforcement. Currently supported by IpcIo module only.
3187#
3188#
3189#	====  The coss store type  ====
3190#
3191#	NP: COSS filesystem in Squid-3 has been deemed too unstable for
3192#	    production use and has thus been removed from this release.
3193#	    We hope that it can be made usable again soon.
3194#
3195#	block-size=n defines the "block size" for COSS cache_dir's.
3196#	Squid uses file numbers as block numbers.  Since file numbers
3197#	are limited to 24 bits, the block size determines the maximum
3198#	size of the COSS partition.  The default is 512 bytes, which
3199#	leads to a maximum cache_dir size of 512<<24, or 8 GB.  Note
3200#	you should not change the coss block size after Squid
3201#	has written some objects to the cache_dir.
3202#
3203#	The coss file store has changed from 2.5. Now it uses a file
3204#	called 'stripe' in the directory names in the config - and
3205#	this will be created by squid -z.
3206#
3207#
3208#	==== COMMON OPTIONS ====
3209#
3210#	no-store	no new objects should be stored to this cache_dir.
3211#
3212#	min-size=n	the minimum object size in bytes this cache_dir
3213#			will accept.  It's used to restrict a cache_dir
3214#			to only store large objects (e.g. AUFS) while
3215#			other stores are optimized for smaller objects
3216#			(e.g. COSS).
3217#			Defaults to 0.
3218#
3219#	max-size=n	the maximum object size in bytes this cache_dir
3220#			supports.
3221#			The value in maximum_object_size directive sets
3222#			the default unless more specific details are
3223#			available (ie a small store capacity).
3224#
3225#	Note: To make optimal use of the max-size limits you should order
3226#	the cache_dir lines with the smallest max-size value first.
3227#
3228#	Note for coss, max-size must be less than COSS_MEMBUF_SZ,
3229#	which can be changed with the --with-coss-membuf-size=N configure
3230#	option.
3231#
3232#Default:
3233# No disk cache. Store cache ojects only in memory.
3234#
3235
3236# Uncomment and adjust the following to add a disk cache directory.
3237#cache_dir ufs /var/spool/squid3 100 16 256
3238
3239#  TAG: store_dir_select_algorithm
3240#	How Squid selects which cache_dir to use when the response
3241#	object will fit into more than one.
3242#
3243#	Regardless of which algorithm is used the cache_dir min-size
3244#	and max-size parameters are obeyed. As such they can affect
3245#	the selection algorithm by limiting the set of considered
3246#	cache_dir.
3247#
3248#	Algorithms:
3249#
3250#		least-load
3251#
3252#	This algorithm is suited to caches with similar cache_dir
3253#	sizes and disk speeds.
3254#
3255#	The disk with the least I/O pending is selected.
3256#	When there are multiple disks with the same I/O load ranking
3257#	the cache_dir with most available capacity is selected.
3258#
3259#	When a mix of cache_dir sizes are configured the faster disks
3260#	have a naturally lower I/O loading and larger disks have more
3261#	capacity. So space used to store objects and data throughput
3262#	may be very unbalanced towards larger disks.
3263#
3264#
3265#		round-robin
3266#
3267#	This algorithm is suited to caches with unequal cache_dir
3268#	disk sizes.
3269#
3270#	Each cache_dir is selected in a rotation. The next suitable
3271#	cache_dir is used.
3272#
3273#	Available cache_dir capacity is only considered in relation
3274#	to whether the object will fit and meets the min-size and
3275#	max-size parameters.
3276#
3277#	Disk I/O loading is only considered to prevent overload on slow
3278#	disks. This algorithm does not spread objects by size, so any
3279#	I/O loading per-disk may appear very unbalanced and volatile.
3280#
3281#Default:
3282# store_dir_select_algorithm least-load
3283
3284#  TAG: max_open_disk_fds
3285#	To avoid having disk as the I/O bottleneck Squid can optionally
3286#	bypass the on-disk cache if more than this amount of disk file
3287#	descriptors are open.
3288#
3289#	A value of 0 indicates no limit.
3290#Default:
3291# no limit
3292
3293#  TAG: cache_swap_low	(percent, 0-100)
3294#	The low-water mark for cache object replacement.
3295#	Replacement begins when the swap (disk) usage is above the
3296#	low-water mark and attempts to maintain utilization near the
3297#	low-water mark.  As swap utilization gets close to high-water
3298#	mark object eviction becomes more aggressive.  If utilization is
3299#	close to the low-water mark less replacement is done each time.
3300#
3301#	Defaults are 90% and 95%. If you have a large cache, 5% could be
3302#	hundreds of MB. If this is the case you may wish to set these
3303#	numbers closer together.
3304#
3305#	See also cache_swap_high
3306#Default:
3307# cache_swap_low 90
3308
3309#  TAG: cache_swap_high	(percent, 0-100)
3310#	The high-water mark for cache object replacement.
3311#	Replacement begins when the swap (disk) usage is above the
3312#	low-water mark and attempts to maintain utilization near the
3313#	low-water mark.  As swap utilization gets close to high-water
3314#	mark object eviction becomes more aggressive.  If utilization is
3315#	close to the low-water mark less replacement is done each time.
3316#
3317#	Defaults are 90% and 95%. If you have a large cache, 5% could be
3318#	hundreds of MB. If this is the case you may wish to set these
3319#	numbers closer together.
3320#
3321#	See also cache_swap_low
3322#Default:
3323# cache_swap_high 95
3324
3325# LOGFILE OPTIONS
3326# -----------------------------------------------------------------------------
3327
3328#  TAG: logformat
3329#	Usage:
3330#
3331#	logformat <name> <format specification>
3332#
3333#	Defines an access log format.
3334#
3335#	The <format specification> is a string with embedded % format codes
3336#
3337#	% format codes all follow the same basic structure where all but
3338#	the formatcode is optional. Output strings are automatically escaped
3339#	as required according to their context and the output format
3340#	modifiers are usually not needed, but can be specified if an explicit
3341#	output format is desired.
3342#
3343#		% ["|[|'|#] [-] [[0]width] [{argument}] formatcode
3344#
3345#		"	output in quoted string format
3346#		[	output in squid text log format as used by log_mime_hdrs
3347#		#	output in URL quoted format
3348#		'	output as-is
3349#
3350#		-	left aligned
3351#
3352#		width	minimum and/or maximum field width:
3353#			    [width_min][.width_max]
3354#			When minimum starts with 0, the field is zero-padded.
3355#			String values exceeding maximum width are truncated.
3356#
3357#		{arg}	argument such as header name etc
3358#
3359#	Format codes:
3360#
3361#		%	a literal % character
3362#		sn	Unique sequence number per log line entry
3363#		err_code    The ID of an error response served by Squid or
3364#				a similar internal error identifier.
3365#		err_detail  Additional err_code-dependent error information.
3366#		note	The annotation specified by the argument. Also
3367#			logs the adaptation meta headers set by the
3368#			adaptation_meta configuration parameter.
3369#			If no argument given all annotations logged.
3370#			The argument may include a separator to use with
3371#			annotation values:
3372#                            name[:separator]
3373#			By default, multiple note values are separated with ","
3374#			and multiple notes are separated with "\r\n".
3375#			When logging named notes with %{name}note, the
3376#			explicitly configured separator is used between note
3377#			values. When logging all notes with %note, the
3378#			explicitly configured separator is used between
3379#			individual notes. There is currently no way to
3380#			specify both value and notes separators when logging
3381#			all notes with %note.
3382#
3383#	Connection related format codes:
3384#
3385#		>a	Client source IP address
3386#		>A	Client FQDN
3387#		>p	Client source port
3388#		>eui	Client source EUI (MAC address, EUI-48 or EUI-64 identifier)
3389#		>la	Local IP address the client connected to
3390#		>lp	Local port number the client connected to
3391#		>qos    Client connection TOS/DSCP value set by Squid
3392#		>nfmark Client connection netfilter mark set by Squid
3393#
3394#		la	Local listening IP address the client connection was connected to.
3395#		lp	Local listening port number the client connection was connected to.
3396#
3397#		<a	Server IP address of the last server or peer connection
3398#		<A	Server FQDN or peer name
3399#		<p	Server port number of the last server or peer connection
3400#		<la	Local IP address of the last server or peer connection
3401#		<lp     Local port number of the last server or peer connection
3402#		<qos	Server connection TOS/DSCP value set by Squid
3403#		<nfmark Server connection netfilter mark set by Squid
3404#
3405#	Time related format codes:
3406#
3407#		ts	Seconds since epoch
3408#		tu	subsecond time (milliseconds)
3409#		tl	Local time. Optional strftime format argument
3410#				default %d/%b/%Y:%H:%M:%S %z
3411#		tg	GMT time. Optional strftime format argument
3412#				default %d/%b/%Y:%H:%M:%S %z
3413#		tr	Response time (milliseconds)
3414#		dt	Total time spent making DNS lookups (milliseconds)
3415#
3416#	Access Control related format codes:
3417#
3418#		et	Tag returned by external acl
3419#		ea	Log string returned by external acl
3420#		un	User name (any available)
3421#		ul	User name from authentication
3422#		ue	User name from external acl helper
3423#		ui	User name from ident
3424#		us	User name from SSL
3425#
3426#	HTTP related format codes:
3427#
3428#		[http::]>h	Original received request header. 
3429#				Usually differs from the request header sent by
3430#				Squid, although most fields are often preserved.
3431#				Accepts optional header field name/value filter
3432#				argument using name[:[separator]element] format.
3433#		[http::]>ha	Received request header after adaptation and
3434#				redirection (pre-cache REQMOD vectoring point).
3435#				Usually differs from the request header sent by
3436#				Squid, although most fields are often preserved.
3437#				Optional header name argument as for >h
3438#		[http::]<h	Reply header. Optional header name argument
3439#				as for >h
3440#		[http::]>Hs	HTTP status code sent to the client
3441#		[http::]<Hs	HTTP status code received from the next hop
3442#		[http::]<bs	Number of HTTP-equivalent message body bytes 
3443#				received from the next hop, excluding chunked
3444#				transfer encoding and control messages.
3445#				Generated FTP/Gopher listings are treated as
3446#				received bodies.
3447#		[http::]mt	MIME content type
3448#		[http::]rm	Request method (GET/POST etc)
3449#		[http::]>rm	Request method from client
3450#		[http::]<rm	Request method sent to server or peer
3451#		[http::]ru	Request URL from client (historic, filtered for logging)
3452#		[http::]>ru	Request URL from client
3453#		[http::]<ru	Request URL sent to server or peer
3454#		[http::]rp	Request URL-Path excluding hostname
3455#		[http::]>rp	Request URL-Path excluding hostname from client
3456#		[http::]<rp	Request URL-Path excluding hostname sento to server or peer
3457#		[http::]rv	Request protocol version
3458#		[http::]>rv	Request protocol version from client
3459#		[http::]<rv	Request protocol version sent to server or peer
3460#		[http::]<st	Sent reply size including HTTP headers
3461#		[http::]>st	Received request size including HTTP headers. In the
3462#				case of chunked requests the chunked encoding metadata
3463#				are not included
3464#		[http::]>sh	Received HTTP request headers size
3465#		[http::]<sh	Sent HTTP reply headers size
3466#		[http::]st	Request+Reply size including HTTP headers
3467#		[http::]<sH	Reply high offset sent
3468#		[http::]<sS	Upstream object size
3469#		[http::]<pt	Peer response time in milliseconds. The timer starts
3470#				when the last request byte is sent to the next hop
3471#				and stops when the last response byte is received.
3472#		[http::]<tt	Total server-side time in milliseconds. The timer 
3473#				starts with the first connect request (or write I/O)
3474#				sent to the first selected peer. The timer stops
3475#				with the last I/O with the last peer.
3476#
3477#	Squid handling related format codes:
3478#
3479#		Ss	Squid request status (TCP_MISS etc)
3480#		Sh	Squid hierarchy status (DEFAULT_PARENT etc)
3481#
3482#	SSL-related format codes:
3483#
3484#		ssl::bump_mode	SslBump decision for the transaction:
3485#
3486#				For CONNECT requests that initiated bumping of
3487#				a connection and for any request received on
3488#				an already bumped connection, Squid logs the
3489#				corresponding SslBump mode ("server-first" or
3490#				"client-first"). See the ssl_bump option for
3491#				more information about these modes.
3492#
3493#				A "none" token is logged for requests that
3494#				triggered "ssl_bump" ACL evaluation matching
3495#				either a "none" rule or no rules at all.
3496#
3497#				In all other cases, a single dash ("-") is
3498#				logged.
3499#
3500#	If ICAP is enabled, the following code becomes available (as
3501#	well as ICAP log codes documented with the icap_log option):
3502#
3503#		icap::tt        Total ICAP processing time for the HTTP
3504#				transaction. The timer ticks when ICAP
3505#				ACLs are checked and when ICAP
3506#				transaction is in progress.
3507#
3508#	If adaptation is enabled the following three codes become available:
3509#
3510#		adapt::<last_h	The header of the last ICAP response or
3511#				meta-information from the last eCAP
3512#				transaction related to the HTTP transaction.
3513#				Like <h, accepts an optional header name
3514#				argument.
3515#
3516#		adapt::sum_trs Summed adaptation transaction response
3517#				times recorded as a comma-separated list in
3518#				the order of transaction start time. Each time
3519#				value is recorded as an integer number,
3520#				representing response time of one or more
3521#				adaptation (ICAP or eCAP) transaction in
3522#				milliseconds.  When a failed transaction is
3523#				being retried or repeated, its time is not
3524#				logged individually but added to the
3525#				replacement (next) transaction. See also:
3526#				adapt::all_trs.
3527#
3528#		adapt::all_trs All adaptation transaction response times.
3529#				Same as adaptation_strs but response times of
3530#				individual transactions are never added
3531#				together. Instead, all transaction response
3532#				times are recorded individually.
3533#
3534#	You can prefix adapt::*_trs format codes with adaptation
3535#	service name in curly braces to record response time(s) specific
3536#	to that service. For example: %{my_service}adapt::sum_trs
3537#
3538#	If SSL is enabled, the following formating codes become available:
3539#
3540#		%ssl::>cert_subject The Subject field of the received client
3541#				SSL certificate or a dash ('-') if Squid has
3542#				received an invalid/malformed certificate or
3543#				no certificate at all. Consider encoding the
3544#				logged value because Subject often has spaces.
3545#
3546#		%ssl::>cert_issuer The Issuer field of the received client
3547#				SSL certificate or a dash ('-') if Squid has
3548#				received an invalid/malformed certificate or
3549#				no certificate at all. Consider encoding the
3550#				logged value because Issuer often has spaces.
3551#
3552#	The default formats available (which do not need re-defining) are:
3553#
3554#logformat squid      %ts.%03tu %6tr %>a %Ss/%03>Hs %<st %rm %ru %[un %Sh/%<a %mt
3555#logformat common     %>a %[ui %[un [%tl] "%rm %ru HTTP/%rv" %>Hs %<st %Ss:%Sh
3556#logformat combined   %>a %[ui %[un [%tl] "%rm %ru HTTP/%rv" %>Hs %<st "%{Referer}>h" "%{User-Agent}>h" %Ss:%Sh
3557#logformat referrer   %ts.%03tu %>a %{Referer}>h %ru
3558#logformat useragent  %>a [%tl] "%{User-Agent}>h"
3559#
3560#	NOTE: When the log_mime_hdrs directive is set to ON.
3561#		The squid, common and combined formats have a safely encoded copy
3562#		of the mime headers appended to each line within a pair of brackets.
3563#
3564#	NOTE: The common and combined formats are not quite true to the Apache definition.
3565#		The logs from Squid contain an extra status and hierarchy code appended.
3566#
3567#Default:
3568# The format definitions squid, common, combined, referrer, useragent are built in.
3569
3570#  TAG: access_log
3571#	Configures whether and how Squid logs HTTP and ICP transactions.
3572#	If access logging is enabled, a single line is logged for every 
3573#	matching HTTP or ICP request. The recommended directive formats are:
3574#
3575#	access_log <module>:<place> [option ...] [acl acl ...]
3576#	access_log none [acl acl ...]
3577#
3578#	The following directive format is accepted but may be deprecated:
3579#	access_log <module>:<place> [<logformat name> [acl acl ...]]
3580#
3581#        In most cases, the first ACL name must not contain the '=' character
3582#	and should not be equal to an existing logformat name. You can always
3583#	start with an 'all' ACL to work around those restrictions.
3584#	
3585#	Will log to the specified module:place using the specified format (which
3586#	must be defined in a logformat directive) those entries which match
3587#	ALL the acl's specified (which must be defined in acl clauses).
3588#	If no acl is specified, all requests will be logged to this destination.
3589#	
3590#	===== Available options for the recommended directive format =====
3591#
3592#	logformat=name		Names log line format (either built-in or
3593#				defined by a logformat directive). Defaults
3594#				to 'squid'.
3595#
3596#	buffer-size=64KB	Defines approximate buffering limit for log
3597#				records (see buffered_logs).  Squid should not
3598#				keep more than the specified size and, hence,
3599#				should flush records before the buffer becomes
3600#				full to avoid overflows under normal
3601#				conditions (the exact flushing algorithm is
3602#				module-dependent though).  The on-error option
3603#				controls overflow handling.
3604#
3605#	on-error=die|drop	Defines action on unrecoverable errors. The
3606#				'drop' action ignores (i.e., does not log)
3607#				affected log records. The default 'die' action
3608#				kills the affected worker. The drop action 
3609#				support has not been tested for modules other
3610#				than tcp.
3611#
3612#	===== Modules Currently available =====
3613#	
3614#	none	Do not log any requests matching these ACL.
3615#		Do not specify Place or logformat name.
3616#	
3617#	stdio	Write each log line to disk immediately at the completion of
3618#		each request.
3619#		Place: the filename and path to be written.
3620#	
3621#	daemon	Very similar to stdio. But instead of writing to disk the log
3622#		line is passed to a daemon helper for asychronous handling instead.
3623#		Place: varies depending on the daemon.
3624#		
3625#		log_file_daemon Place: the file name and path to be written.
3626#	
3627#	syslog	To log each request via syslog facility.
3628#		Place: The syslog facility and priority level for these entries.
3629#		Place Format:  facility.priority
3630#
3631#		where facility could be any of:
3632#			authpriv, daemon, local0 ... local7 or user.
3633#
3634#		And priority could be any of:
3635#			err, warning, notice, info, debug.
3636#	
3637#	udp	To send each log line as text data to a UDP receiver.
3638#		Place: The destination host name or IP and port.
3639#		Place Format:   //host:port
3640#
3641#	tcp	To send each log line as text data to a TCP receiver.
3642#		Lines may be accumulated before sending (see buffered_logs).
3643#		Place: The destination host name or IP and port.
3644#		Place Format:   //host:port
3645#
3646#	Default:
3647#		access_log daemon:/var/log/squid3/access.log squid
3648#Default:
3649# access_log daemon:/var/log/squid3/access.log squid
3650
3651#  TAG: icap_log
3652#	ICAP log files record ICAP transaction summaries, one line per
3653#	transaction.
3654#
3655#	The icap_log option format is:
3656#	icap_log <filepath> [<logformat name> [acl acl ...]]
3657#	icap_log none [acl acl ...]]
3658#	
3659#	Please see access_log option documentation for details. The two
3660#	kinds of logs share the overall configuration approach and many
3661#	features.
3662#
3663#	ICAP processing of a single HTTP message or transaction may
3664#	require multiple ICAP transactions.  In such cases, multiple
3665#	ICAP transaction log lines will correspond to a single access
3666#	log line.
3667#
3668#	ICAP log uses logformat codes that make sense for an ICAP
3669#	transaction. Header-related codes are applied to the HTTP header
3670#	embedded in an ICAP server response, with the following caveats:
3671#	For REQMOD, there is no HTTP response header unless the ICAP
3672#	server performed request satisfaction. For RESPMOD, the HTTP
3673#	request header is the header sent to the ICAP server. For
3674#	OPTIONS, there are no HTTP headers.
3675#
3676#	The following format codes are also available for ICAP logs:
3677#
3678#		icap::<A	ICAP server IP address. Similar to <A.
3679#
3680#		icap::<service_name	ICAP service name from the icap_service
3681#				option in Squid configuration file.
3682#
3683#		icap::ru	ICAP Request-URI. Similar to ru.
3684#
3685#		icap::rm	ICAP request method (REQMOD, RESPMOD, or 
3686#				OPTIONS). Similar to existing rm.
3687#
3688#		icap::>st	Bytes sent to the ICAP server (TCP payload
3689#				only; i.e., what Squid writes to the socket).
3690#
3691#		icap::<st	Bytes received from the ICAP server (TCP
3692#				payload only; i.e., what Squid reads from
3693#				the socket).
3694#
3695#		icap::<bs	Number of message body bytes received from the
3696#				ICAP server. ICAP message body, if any, usually
3697#				includes encapsulated HTTP message headers and
3698#				possibly encapsulated HTTP message body. The
3699#				HTTP body part is dechunked before its size is
3700#				computed.
3701#
3702#		icap::tr 	Transaction response time (in
3703#				milliseconds).  The timer starts when
3704#				the ICAP transaction is created and
3705#				stops when the transaction is completed.
3706#				Similar to tr.
3707#
3708#		icap::tio	Transaction I/O time (in milliseconds). The
3709#				timer starts when the first ICAP request
3710#				byte is scheduled for sending. The timers
3711#				stops when the last byte of the ICAP response
3712#				is received.
3713#
3714#		icap::to 	Transaction outcome: ICAP_ERR* for all
3715#				transaction errors, ICAP_OPT for OPTION
3716#				transactions, ICAP_ECHO for 204
3717#				responses, ICAP_MOD for message
3718#				modification, and ICAP_SAT for request
3719#				satisfaction. Similar to Ss.
3720#
3721#		icap::Hs	ICAP response status code. Similar to Hs.
3722#
3723#		icap::>h	ICAP request header(s). Similar to >h.
3724#
3725#		icap::<h	ICAP response header(s). Similar to <h.
3726#
3727#	The default ICAP log format, which can be used without an explicit
3728#	definition, is called icap_squid:
3729#
3730#logformat icap_squid %ts.%03tu %6icap::tr %>a %icap::to/%03icap::Hs %icap::<size %icap::rm %icap::ru% %un -/%icap::<A -
3731#
3732#	See also: logformat, log_icap, and %adapt::<last_h 
3733#Default:
3734# none
3735
3736#  TAG: logfile_daemon
3737#	Specify the path to the logfile-writing daemon. This daemon is
3738#	used to write the access and store logs, if configured.
3739#
3740#	Squid sends a number of commands to the log daemon:
3741#	  L<data>\n - logfile data
3742#	  R\n - rotate file
3743#	  T\n - truncate file
3744#	  O\n - reopen file
3745#	  F\n - flush file
3746#	  r<n>\n - set rotate count to <n>
3747#	  b<n>\n - 1 = buffer output, 0 = don't buffer output
3748#
3749#	No responses is expected.
3750#Default:
3751# logfile_daemon /usr/lib/squid3/log_file_daemon
3752
3753#  TAG: log_access
3754#	Remove this line. Use acls with access_log directives to control access logging
3755#Default:
3756# none
3757
3758#  TAG: log_icap
3759#	Remove this line. Use acls with icap_log directives to control icap logging
3760#Default:
3761# none
3762
3763#  TAG: stats_collection	allow|deny acl acl...
3764#	This options allows you to control which requests gets accounted
3765#	in performance counters.
3766#
3767#	This clause only supports fast acl types.
3768#	See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
3769#Default:
3770# Allow logging for all transactions.
3771
3772#  TAG: cache_store_log
3773#	Logs the activities of the storage manager.  Shows which
3774#	objects are ejected from the cache, and which objects are
3775#	saved and for how long.
3776#	There are not really utilities to analyze this data, so you can safely
3777#	disable it (the default).
3778#	
3779#	Store log uses modular logging outputs. See access_log for the list
3780#	of modules supported.
3781#	
3782#	Example:
3783#		cache_store_log stdio:/var/log/squid3/store.log
3784#		cache_store_log daemon:/var/log/squid3/store.log
3785#Default:
3786# none
3787
3788#  TAG: cache_swap_state
3789#	Location for the cache "swap.state" file. This index file holds
3790#	the metadata of objects saved on disk.  It is used to rebuild
3791#	the cache during startup.  Normally this file resides in each
3792#	'cache_dir' directory, but you may specify an alternate
3793#	pathname here.  Note you must give a full filename, not just
3794#	a directory. Since this is the index for the whole object
3795#	list you CANNOT periodically rotate it!
3796#
3797#	If %s can be used in the file name it will be replaced with a
3798#	a representation of the cache_dir name where each / is replaced
3799#	with '.'. This is needed to allow adding/removing cache_dir
3800#	lines when cache_swap_log is being used.
3801#
3802#	If have more than one 'cache_dir', and %s is not used in the name
3803#	these swap logs will have names such as:
3804#
3805#		cache_swap_log.00
3806#		cache_swap_log.01
3807#		cache_swap_log.02
3808#
3809#	The numbered extension (which is added automatically)
3810#	corresponds to the order of the 'cache_dir' lines in this
3811#	configuration file.  If you change the order of the 'cache_dir'
3812#	lines in this file, these index files will NOT correspond to
3813#	the correct 'cache_dir' entry (unless you manually rename
3814#	them).  We recommend you do NOT use this option.  It is
3815#	better to keep these index files in each 'cache_dir' directory.
3816#Default:
3817# Store the journal inside its cache_dir
3818
3819#  TAG: logfile_rotate
3820#	Specifies the number of logfile rotations to make when you
3821#	type 'squid -k rotate'. The default is 10, which will rotate
3822#	with extensions 0 through 9. Setting logfile_rotate to 0 will
3823#	disable the file name rotation, but the logfiles are still closed
3824#	and re-opened. This will enable you to rename the logfiles
3825#	yourself just before sending the rotate signal.
3826#
3827#	Note, the 'squid -k rotate' command normally sends a USR1
3828#	signal to the running squid process.  In certain situations
3829#	(e.g. on Linux with Async I/O), USR1 is used for other
3830#	purposes, so -k rotate uses another signal.  It is best to get
3831#	in the habit of using 'squid -k rotate' instead of 'kill -USR1
3832#	<pid>'.
3833#
3834#	Note, from Squid-3.1 this option is only a default for cache.log,
3835#	that log can be rotated separately by using debug_options.
3836#
3837#	Note2, for Debian/Linux the default of logfile_rotate is
3838#	zero, since it includes external logfile-rotation methods.
3839#Default:
3840# logfile_rotate 0
3841
3842#  TAG: emulate_httpd_log
3843#	Replace this with an access_log directive using the format 'common' or 'combined'.
3844#Default:
3845# none
3846
3847#  TAG: log_ip_on_direct
3848#	Remove this option from your config. To log server or peer names use %<A in the log format.
3849#Default:
3850# none
3851
3852#  TAG: mime_table
3853#	Path to Squid's icon configuration file.
3854#
3855#	You shouldn't need to change this, but the default file contains
3856#	examples and formatting information if you do.
3857#Default:
3858# mime_table /usr/share/squid3/mime.conf
3859
3860#  TAG: log_mime_hdrs	on|off
3861#	The Cache can record both the request and the response MIME
3862#	headers for each HTTP transaction.  The headers are encoded
3863#	safely and will appear as two bracketed fields at the end of
3864#	the access log (for either the native or httpd-emulated log
3865#	formats).  To enable this logging set log_mime_hdrs to 'on'.
3866#Default:
3867# log_mime_hdrs off
3868
3869#  TAG: useragent_log
3870#	Replace this with an access_log directive using the format 'useragent'.
3871#Default:
3872# none
3873
3874#  TAG: referer_log
3875#	Replace this with an access_log directive using the format 'referrer'.
3876#Default:
3877# none
3878
3879#  TAG: pid_filename
3880#	A filename to write the process-id to.  To disable, enter "none".
3881#Default:
3882# pid_filename /var/run/squid3.pid
3883
3884#  TAG: log_fqdn
3885#	Remove this option from your config. To log FQDN use %>A in the log format.
3886#Default:
3887# none
3888
3889#  TAG: client_netmask
3890#	A netmask for client addresses in logfiles and cachemgr output.
3891#	Change this to protect the privacy of your cache clients.
3892#	A netmask of 255.255.255.0 will log all IP's in that range with
3893#	the last digit set to '0'.
3894#Default:
3895# Log full client IP address
3896
3897#  TAG: forward_log
3898#	Use a regular access.log with ACL limiting it to MISS events.
3899#Default:
3900# none
3901
3902#  TAG: strip_query_terms
3903#	By default, Squid strips query terms from requested URLs before
3904#	logging.  This protects your user's privacy and reduces log size.
3905#
3906#	When investigating HIT/MISS or other caching behaviour you
3907#	will need to disable this to see the full URL used by Squid.
3908#Default:
3909# strip_query_terms on
3910
3911#  TAG: buffered_logs	on|off
3912#	Whether to write/send access_log records ASAP or accumulate them and
3913#	then write/send them in larger chunks. Buffering may improve
3914#	performance because it decreases the number of I/Os. However,
3915#	buffering increases the delay before log records become available to
3916#	the final recipient (e.g., a disk file or logging daemon) and,
3917#	hence, increases the risk of log records loss.
3918#
3919#	Note that even when buffered_logs are off, Squid may have to buffer
3920#	records if it cannot write/send them immediately due to pending I/Os
3921#	(e.g., the I/O writing the previous log record) or connectivity loss.
3922#
3923#	Currently honored by 'daemon' and 'tcp' access_log modules only.
3924#Default:
3925# buffered_logs off
3926
3927#  TAG: netdb_filename
3928#	Where Squid stores it's netdb journal.
3929#	When enabled this journal preserves netdb state between restarts.
3930#
3931#	To disable, enter "none".
3932#Default:
3933# netdb_filename stdio:/var/log/squid3/netdb.state
3934
3935# OPTIONS FOR TROUBLESHOOTING
3936# -----------------------------------------------------------------------------
3937
3938#  TAG: cache_log
3939#	Squid administrative logging file.
3940#
3941#	This is where general information about Squid behavior goes. You can
3942#	increase the amount of data logged to this file and how often it is
3943#	rotated with "debug_options"
3944#Default:
3945# cache_log /var/log/squid3/cache.log
3946
3947#  TAG: debug_options
3948#	Logging options are set as section,level where each source file
3949#	is assigned a unique section.  Lower levels result in less
3950#	output,  Full debugging (level 9) can result in a very large
3951#	log file, so be careful.
3952#
3953#	The magic word "ALL" sets debugging levels for all sections.
3954#	The default is to run with "ALL,1" to record important warnings.
3955#
3956#	The rotate=N option can be used to keep more or less of these logs
3957#	than would otherwise be kept by logfile_rotate.
3958#	For most uses a single log should be enough to monitor current
3959#	events affecting Squid.
3960#Default:
3961# Log all critical and important messages.
3962
3963#  TAG: coredump_dir
3964#	By default Squid leaves core files in the directory from where
3965#	it was started. If you set 'coredump_dir' to a directory
3966#	that exists, Squid will chdir() to that directory at startup
3967#	and coredump files will be left there.
3968#
3969#Default:
3970# Use the directory from where Squid was started.
3971#
3972
3973# Leave coredumps in the first cache dir
3974coredump_dir /var/spool/squid3
3975
3976# OPTIONS FOR FTP GATEWAYING
3977# -----------------------------------------------------------------------------
3978
3979#  TAG: ftp_user
3980#	If you want the anonymous login password to be more informative
3981#	(and enable the use of picky FTP servers), set this to something
3982#	reasonable for your domain, like wwwuser@somewhere.net
3983#
3984#	The reason why this is domainless by default is the
3985#	request can be made on the behalf of a user in any domain,
3986#	depending on how the cache is used.
3987#	Some FTP server also validate the email address is valid
3988#	(for example perl.com).
3989#Default:
3990# ftp_user Squid@
3991
3992#  TAG: ftp_passive
3993#	If your firewall does not allow Squid to use passive
3994#	connections, turn off this option.
3995#
3996#	Use of ftp_epsv_all option requires this to be ON.
3997#Default:
3998# ftp_passive on
3999
4000#  TAG: ftp_epsv_all
4001#	FTP Protocol extensions permit the use of a special "EPSV ALL" command.
4002#
4003#	NATs may be able to put the connection on a "fast path" through the
4004#	translator, as the EPRT command will never be used and therefore,
4005#	translation of the data portion of the segments will never be needed.
4006#
4007#	When a client only expects to do two-way FTP transfers this may be
4008#	useful.
4009#	If squid finds that it must do a three-way FTP transfer after issuing
4010#	an EPSV ALL command, the FTP session will fail.
4011#
4012#	If you have any doubts about this option do not use it.
4013#	Squid will nicely attempt all other connection methods.
4014#
4015#	Requires ftp_passive to be ON (default) for any effect.
4016#Default:
4017# ftp_epsv_all off
4018
4019#  TAG: ftp_epsv
4020#	FTP Protocol extensions permit the use of a special "EPSV" command.
4021#
4022#	NATs may be able to put the connection on a "fast path" through the
4023#	translator using EPSV, as the EPRT command will never be used
4024#	and therefore, translation of the data portion of the segments 
4025#	will never be needed.
4026#
4027#	Turning this OFF will prevent EPSV being attempted.
4028#	WARNING: Doing so will convert Squid back to the old behavior with all
4029#	the related problems with external NAT devices/layers.
4030#
4031#	Requires ftp_passive to be ON (default) for any effect.
4032#Default:
4033# ftp_epsv on
4034
4035#  TAG: ftp_eprt
4036#	FTP Protocol extensions permit the use of a special "EPRT" command.
4037#
4038#	This extension provides a protocol neutral alternative to the
4039#	IPv4-only PORT command. When supported it enables active FTP data
4040#	channels over IPv6 and efficient NAT handling.
4041#
4042#	Turning this OFF will prevent EPRT being attempted and will skip
4043#	straight to using PORT for IPv4 servers.
4044#
4045#	Some devices are known to not handle this extension correctly and
4046#	may result in crashes. Devices which suport EPRT enough to fail
4047#	cleanly will result in Squid attempting PORT anyway. This directive
4048#	should only be disabled when EPRT results in device failures.
4049#
4050#	WARNING: Doing so will convert Squid back to the old behavior with all
4051#	the related problems with external NAT devices/layers and IPv4-only FTP.
4052#Default:
4053# ftp_eprt on
4054
4055#  TAG: ftp_sanitycheck
4056#	For security and data integrity reasons Squid by default performs
4057#	sanity checks of the addresses of FTP data connections ensure the
4058#	data connection is to the requested server. If you need to allow
4059#	FTP connections to servers using another IP address for the data
4060#	connection turn this off.
4061#Default:
4062# ftp_sanitycheck on
4063
4064#  TAG: ftp_telnet_protocol
4065#	The FTP protocol is officially defined to use the telnet protocol
4066#	as transport channel for the control connection. However, many
4067#	implementations are broken and does not respect this aspect of
4068#	the FTP protocol.
4069#
4070#	If you have trouble accessing files with ASCII code 255 in the
4071#	path or similar problems involving this ASCII code you can
4072#	try setting this directive to off. If that helps, report to the
4073#	operator of the FTP server in question that their FTP server
4074#	is broken and does not follow the FTP standard.
4075#Default:
4076# ftp_telnet_protocol on
4077
4078# OPTIONS FOR EXTERNAL SUPPORT PROGRAMS
4079# -----------------------------------------------------------------------------
4080
4081#  TAG: diskd_program
4082#	Specify the location of the diskd executable.
4083#	Note this is only useful if you have compiled in
4084#	diskd as one of the store io modules.
4085#Default:
4086# diskd_program /usr/lib/squid3/diskd
4087
4088#  TAG: unlinkd_program
4089#	Specify the location of the executable for file deletion process.
4090#Default:
4091# unlinkd_program /usr/lib/squid3/unlinkd
4092
4093#  TAG: pinger_program
4094#	Specify the location of the executable for the pinger process.
4095#Default:
4096# pinger_program /usr/lib/squid3/pinger
4097
4098#  TAG: pinger_enable
4099#	Control whether the pinger is active at run-time.
4100#	Enables turning ICMP pinger on and off with a simple
4101#	squid -k reconfigure.
4102#Default:
4103# pinger_enable on
4104
4105# OPTIONS FOR URL REWRITING
4106# -----------------------------------------------------------------------------
4107
4108#  TAG: url_rewrite_program
4109#	Specify the location of the executable URL rewriter to use.
4110#	Since they can perform almost any function there isn't one included.
4111#
4112#	For each requested URL, the rewriter will receive on line with the format
4113#
4114#	  [channel-ID <SP>] URL <SP> client_ip "/" fqdn <SP> user <SP> method [<SP> kv-pairs]<NL>
4115#
4116#
4117#	After processing the request the helper must reply using the following format:
4118#
4119#	  [channel-ID <SP>] result [<SP> kv-pairs]
4120#
4121#	The result code can be:
4122#
4123#	  OK status=30N url="..."
4124#		Redirect the URL to the one supplied in 'url='.
4125#		'status=' is optional and contains the status code to send
4126#		the client in Squids HTTP response. It must be one of the
4127#		HTTP redirect status codes: 301, 302, 303, 307, 308.
4128#		When no status is given Squid will use 302.
4129#
4130#	  OK rewrite-url="..."
4131#		Rewrite the URL to the one supplied in 'rewrite-url='.
4132#		The new URL is fetched directly by Squid and returned to
4133#		the client as the response to its request.
4134#
4135#	  OK
4136#		When neither of url= and rewrite-url= are sent Squid does
4137#		not change the URL.
4138#
4139#	  ERR
4140#		Do not change the URL.
4141#
4142#	  BH
4143#		An internal error occurred in the helper, preventing
4144#		a result being identified. The 'message=' key name is
4145#		reserved for delivering a log message.
4146#
4147#
4148#	In the future, the interface protocol will be extended with
4149#	key=value pairs ("kv-pairs" shown above).  Helper programs
4150#	should be prepared to receive and possibly ignore additional
4151#	whitespace-separated tokens on each input line.
4152#
4153#	When using the concurrency= option the protocol is changed by
4154#	introducing a query channel tag in front of the request/response.
4155#	The query channel tag is a number between 0 and concurrency-1.
4156#	This value must be echoed back unchanged to Squid as the first part
4157#	of the response relating to its request.
4158#
4159#	WARNING: URL re-writing ability should be avoided whenever possible.
4160#		 Use the URL redirect form of response instead.
4161#
4162#	Re-write creates a difference in the state held by the client
4163#	and server. Possibly causing confusion when the server response
4164#	contains snippets of its view state. Embeded URLs, response
4165#	and content Location headers, etc. are not re-written by this
4166#	interface.
4167#
4168#	By default, a URL rewriter is not used.
4169#Default:
4170# none
4171
4172#  TAG: url_rewrite_children
4173#	The maximum number of redirector processes to spawn. If you limit
4174#	it too few Squid will have to wait for them to process a backlog of
4175#	URLs, slowing it down. If you allow too many they will use RAM
4176#	and other system resources noticably.
4177#	
4178#	The startup= and idle= options allow some measure of skew in your
4179#	tuning.
4180#	
4181#		startup=
4182#	
4183#	Sets a minimum of how many processes are to be spawned when Squid
4184#	starts or reconfigures. When set to zero the first request will
4185#	cause spawning of the first child process to handle it.
4186#	
4187#	Starting too few will cause an initial slowdown in traffic as Squid
4188#	attempts to simultaneously spawn enough processes to cope.
4189#	
4190#		idle=
4191#	
4192#	Sets a minimum of how many processes Squid is to try and keep available
4193#	at all times. When traffic begins to rise above what the existing
4194#	processes can handle this many more will be spawned up to the maximum
4195#	configured. A minimum setting of 1 is required.
4196#
4197#		concurrency=
4198#
4199#	The number of requests each redirector helper can handle in
4200#	parallel. Defaults to 0 which indicates the redirector
4201#	is a old-style single threaded redirector.
4202#
4203#	When this directive is set to a value >= 1 then the protocol
4204#	used to communicate with the helper is modified to include
4205#	an ID in front of the request/response. The ID from the request
4206#	must be echoed back with the response to that request.
4207#Default:
4208# url_rewrite_children 20 startup=0 idle=1 concurrency=0
4209
4210#  TAG: url_rewrite_host_header
4211#	To preserve same-origin security policies in browsers and
4212#	prevent Host: header forgery by redirectors Squid rewrites
4213#	any Host: header in redirected requests.
4214#	
4215#	If you are running an accelerator this may not be a wanted
4216#	effect of a redirector. This directive enables you disable
4217#	Host: alteration in reverse-proxy traffic.
4218#	
4219#	WARNING: Entries are cached on the result of the URL rewriting
4220#	process, so be careful if you have domain-virtual hosts.
4221#	
4222#	WARNING: Squid and other software verifies the URL and Host
4223#	are matching, so be careful not to relay through other proxies
4224#	or inspecting firewalls with this disabled.
4225#Default:
4226# url_rewrite_host_header on
4227
4228#  TAG: url_rewrite_access
4229#	If defined, this access list specifies which requests are
4230#	sent to the redirector processes.
4231#
4232#	This clause supports both fast and slow acl types.
4233#	See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
4234#Default:
4235# Allow, unless rules exist in squid.conf.
4236
4237#  TAG: url_rewrite_bypass
4238#	When this is 'on', a request will not go through the
4239#	redirector if all the helpers are busy.  If this is 'off'
4240#	and the redirector queue grows too large, Squid will exit
4241#	with a FATAL error and ask you to increase the number of
4242#	redirectors.  You should only enable this if the redirectors
4243#	are not critical to your caching system.  If you use
4244#	redirectors for access control, and you enable this option,
4245#	users may have access to pages they should not
4246#	be allowed to request.
4247#Default:
4248# url_rewrite_bypass off
4249
4250# OPTIONS FOR STORE ID
4251# -----------------------------------------------------------------------------
4252
4253#  TAG: store_id_program
4254#	Specify the location of the executable StoreID helper to use.
4255#	Since they can perform almost any function there isn't one included.
4256#
4257#	For each requested URL, the helper will receive one line with the format
4258#
4259#	  [channel-ID <SP>] URL <SP> client_ip "/" fqdn <SP> user <SP> method [<SP> kv-pairs]<NL>
4260#
4261#
4262#	After processing the request the helper must reply using the following format:
4263#
4264#	  [channel-ID <SP>] result [<SP> kv-pairs]
4265#
4266#	The result code can be:
4267#
4268#	  OK store-id="..."
4269#		Use the StoreID supplied in 'store-id='.
4270#
4271#	  ERR
4272#		The default is to use HTTP request URL as the store ID.
4273#
4274#	  BH
4275#		An internal error occured in the helper, preventing
4276#		a result being identified.
4277#
4278#
4279#	Helper programs should be prepared to receive and possibly ignore additional
4280#	kv-pairs with keys they do not support.
4281#
4282#	When using the concurrency= option the protocol is changed by
4283#	introducing a query channel tag in front of the request/response.
4284#	The query channel tag is a number between 0 and concurrency-1.
4285#	This value must be echoed back unchanged to Squid as the first part
4286#	of the response relating to its request.
4287#
4288#	NOTE: when using StoreID refresh_pattern will apply to the StoreID
4289#	      returned from the helper and not the URL.
4290#
4291#	WARNING: Wrong StoreID value returned by a careless helper may result
4292#	         in the wrong cached response returned to the user.
4293#
4294#	By default, a StoreID helper is not used.
4295#Default:
4296# none
4297
4298#  TAG: store_id_children
4299#	The maximum number of StoreID helper processes to spawn. If you limit
4300#	it too few Squid will have to wait for them to process a backlog of
4301#	requests, slowing it down. If you allow too many they will use RAM
4302#	and other system resources noticably.
4303#	
4304#	The startup= and idle= options allow some measure of skew in your
4305#	tuning.
4306#	
4307#		startup=
4308#	
4309#	Sets a minimum of how many processes are to be spawned when Squid
4310#	starts or reconfigures. When set to zero the first request will
4311#	cause spawning of the first child process to handle it.
4312#	
4313#	Starting too few will cause an initial slowdown in traffic as Squid
4314#	attempts to simultaneously spawn enough processes to cope.
4315#	
4316#		idle=
4317#	
4318#	Sets a minimum of how many processes Squid is to try and keep available
4319#	at all times. When traffic begins to rise above what the existing
4320#	processes can handle this many more will be spawned up to the maximum
4321#	configured. A minimum setting of 1 is required.
4322#
4323#		concurrency=
4324#
4325#	The number of requests each storeID helper can handle in
4326#	parallel. Defaults to 0 which indicates the helper
4327#	is a old-style single threaded program.
4328#
4329#	When this directive is set to a value >= 1 then the protocol
4330#	used to communicate with the helper is modified to include
4331#	an ID in front of the request/response. The ID from the request
4332#	must be echoed back with the response to that request.
4333#Default:
4334# store_id_children 20 startup=0 idle=1 concurrency=0
4335
4336#  TAG: store_id_access
4337#	If defined, this access list specifies which requests are
4338#	sent to the StoreID processes.  By default all requests
4339#	are sent.
4340#
4341#	This clause supports both fast and slow acl types.
4342#	See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
4343#Default:
4344# Allow, unless rules exist in squid.conf.
4345
4346#  TAG: store_id_bypass
4347#	When this is 'on', a request will not go through the
4348#	helper if all helpers are busy.  If this is 'off'
4349#	and the helper queue grows too large, Squid will exit
4350#	with a FATAL error and ask you to increase the number of
4351#	helpers.  You should only enable this if the helperss
4352#	are not critical to your caching system.  If you use
4353#	helpers for critical caching components, and you enable this 
4354#	option,	users may not get objects from cache.
4355#Default:
4356# store_id_bypass on
4357
4358# OPTIONS FOR TUNING THE CACHE
4359# -----------------------------------------------------------------------------
4360
4361#  TAG: cache
4362#	A list of ACL elements which, if matched and denied, cause the request to
4363#	not be satisfied from the cache and the reply to not be cached.
4364#	In other words, use this to force certain objects to never be cached.
4365#
4366#	You must use the words 'allow' or 'deny' to indicate whether items
4367#	matching the ACL should be allowed or denied into the cache.
4368#
4369#	This clause supports both fast and slow acl types.
4370#	See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
4371#Default:
4372# Allow caching, unless rules exist in squid.conf.
4373
4374#  TAG: max_stale	time-units
4375#	This option puts an upper limit on how stale content Squid
4376#	will serve from the cache if cache validation fails.
4377#	Can be overriden by the refresh_pattern max-stale option.
4378#Default:
4379# max_stale 1 week
4380
4381#  TAG: refresh_pattern
4382#	usage: refresh_pattern [-i] regex min percent max [options]
4383#
4384#	By default, regular expressions are CASE-SENSITIVE.  To make
4385#	them case-insensitive, use the -i option.
4386#
4387#	'Min' is the time (in minutes) an object without an explicit
4388#	expiry time should be considered fresh. The recommended
4389#	value is 0, any higher values may cause dynamic applications
4390#	to be erroneously cached unless the application designer
4391#	has taken the appropriate actions.
4392#
4393#	'Percent' is a percentage of the objects age (time since last
4394#	modification age) an object without explicit expiry time
4395#	will be considered fresh.
4396#
4397#	'Max' is an upper limit on how long objects without an explicit
4398#	expiry time will be considered fresh.
4399#
4400#	options: override-expire
4401#		 override-lastmod
4402#		 reload-into-ims
4403#		 ignore-reload
4404#		 ignore-no-store
4405#		 ignore-must-revalidate
4406#		 ignore-private
4407#		 ignore-auth
4408#		 max-stale=NN
4409#		 refresh-ims
4410#		 store-stale
4411#
4412#		override-expire enforces min age even if the server
4413#		sent an explicit expiry time (e.g., with the
4414#		Expires: header or Cache-Control: max-age). Doing this
4415#		VIOLATES the HTTP standard.  Enabling this feature
4416#		could make you liable for problems which it causes.
4417#
4418#		Note: override-expire does not enforce staleness - it only extends
4419#		freshness / min. If the server returns a Expires time which
4420#		is longer than your max time, Squid will still consider
4421#		the object fresh for that period of time.
4422#
4423#		override-lastmod enforces min age even on objects
4424#		that were modified recently.
4425#
4426#		reload-into-ims changes a client no-cache or ``reload''
4427#		request for a cached entry into a conditional request using
4428#		If-Modified-Since and/or If-None-Match headers, provided the
4429#		cached entry has a Last-Modified and/or a strong ETag header.
4430#		Doing this VIOLATES the HTTP standard. Enabling this feature
4431#		could make you liable for problems which it causes.
4432#
4433#		ignore-reload ignores a client no-cache or ``reload''
4434#		header. Doing this VIOLATES the HTTP standard. Enabling
4435#		this feature could make you liable for problems which
4436#		it causes.
4437#
4438#		ignore-no-store ignores any ``Cache-control: no-store''
4439#		headers received from a server. Doing this VIOLATES
4440#		the HTTP standard. Enabling this feature could make you
4441#		liable for problems which it causes.
4442#
4443#		ignore-must-revalidate ignores any ``Cache-Control: must-revalidate``
4444#		headers received from a server. Doing this VIOLATES
4445#		the HTTP standard. Enabling this feature could make you
4446#		liable for problems which it causes.
4447#
4448#		ignore-private ignores any ``Cache-control: private''
4449#		headers received from a server. Doing this VIOLATES
4450#		the HTTP standard. Enabling this feature could make you
4451#		liable for problems which it causes.
4452#
4453#		ignore-auth caches responses to requests with authorization,
4454#		as if the originserver had sent ``Cache-control: public''
4455#		in the response header. Doing this VIOLATES the HTTP standard.
4456#		Enabling this feature could make you liable for problems which
4457#		it causes.
4458#
4459#		refresh-ims causes squid to contact the origin server
4460#		when a client issues an If-Modified-Since request. This
4461#		ensures that the client will receive an updated version
4462#		if one is available.
4463#
4464#		store-stale stores responses even if they don't have explicit 
4465#		freshness or a validator (i.e., Last-Modified or an ETag) 
4466#		present, or if they're already stale. By default, Squid will 
4467#		not cache such responses because they usually can't be
4468#		reused. Note that such responses will be stale by default.
4469#
4470#		max-stale=NN provide a maximum staleness factor. Squid won't
4471#		serve objects more stale than this even if it failed to
4472#		validate the object. Default: use the max_stale global limit.
4473#
4474#	Basically a cached object is:
4475#
4476#		FRESH if expires < now, else STALE
4477#		STALE if age > max
4478#		FRESH if lm-factor < percent, else STALE
4479#		FRESH if age < min
4480#		else STALE
4481#
4482#	The refresh_pattern lines are checked in the order listed here.
4483#	The first entry which matches is used.  If none of the entries
4484#	match the default will be used.
4485#
4486#	Note, you must uncomment all the default lines if you want
4487#	to change one. The default setting is only active if none is
4488#	used.
4489#
4490#
4491
4492#
4493# Add any of your own refresh_pattern entries above these.
4494#
4495refresh_pattern ^ftp:		1440	20%	10080
4496refresh_pattern ^gopher:	1440	0%	1440
4497refresh_pattern -i (/cgi-bin/|\?) 0	0%	0
4498refresh_pattern .		0	20%	4320
4499
4500#  TAG: quick_abort_min	(KB)
4501#Default:
4502# quick_abort_min 16 KB
4503
4504#  TAG: quick_abort_max	(KB)
4505#Default:
4506# quick_abort_max 16 KB
4507
4508#  TAG: quick_abort_pct	(percent)
4509#	The cache by default continues downloading aborted requests
4510#	which are almost completed (less than 16 KB remaining). This
4511#	may be undesirable on slow (e.g. SLIP) links and/or very busy
4512#	caches.  Impatient users may tie up file descriptors and
4513#	bandwidth by repeatedly requesting and immediately aborting
4514#	downloads.
4515#
4516#	When the user aborts a request, Squid will check the
4517#	quick_abort values to the amount of data transferred until
4518#	then.
4519#
4520#	If the transfer has less than 'quick_abort_min' KB remaining,
4521#	it will finish the retrieval.
4522#
4523#	If the transfer has more than 'quick_abort_max' KB remaining,
4524#	it will abort the retrieval.
4525#
4526#	If more than 'quick_abort_pct' of the transfer has completed,
4527#	it will finish the retrieval.
4528#
4529#	If you do not want any retrieval to continue after the client
4530#	has aborted, set both 'quick_abort_min' and 'quick_abort_max'
4531#	to '0 KB'.
4532#
4533#	If you want retrievals to always continue if they are being
4534#	cached set 'quick_abort_min' to '-1 KB'.
4535#Default:
4536# quick_abort_pct 95
4537
4538#  TAG: read_ahead_gap	buffer-size
4539#	The amount of data the cache will buffer ahead of what has been
4540#	sent to the client when retrieving an object from another server.
4541#Default:
4542# read_ahead_gap 16 KB
4543
4544#  TAG: negative_ttl	time-units
4545#	Set the Default Time-to-Live (TTL) for failed requests.
4546#	Certain types of failures (such as "connection refused" and
4547#	"404 Not Found") are able to be negatively-cached for a short time.
4548#	Modern web servers should provide Expires: header, however if they
4549#	do not this can provide a minimum TTL.
4550#	The default is not to cache errors with unknown expiry details.
4551#
4552#	Note that this is different from negative caching of DNS lookups.
4553#
4554#	WARNING: Doing this VIOLATES the HTTP standard.  Enabling
4555#	this feature could make you liable for problems which it
4556#	causes.
4557#Default:
4558# negative_ttl 0 seconds
4559
4560#  TAG: positive_dns_ttl	time-units
4561#	Upper limit on how long Squid will cache positive DNS responses.
4562#	Default is 6 hours (360 minutes). This directive must be set
4563#	larger than negative_dns_ttl.
4564#Default:
4565# positive_dns_ttl 6 hours
4566
4567#  TAG: negative_dns_ttl	time-units
4568#	Time-to-Live (TTL) for negative caching of failed DNS lookups.
4569#	This also sets the lower cache limit on positive lookups.
4570#	Minimum value is 1 second, and it is not recommendable to go
4571#	much below 10 seconds.
4572#Default:
4573# negative_dns_ttl 1 minutes
4574
4575#  TAG: range_offset_limit	size [acl acl...]
4576#	usage: (size) [units] [[!]aclname]
4577#	
4578#	Sets an upper limit on how far (number of bytes) into the file 
4579#	a Range request	may be to cause Squid to prefetch the whole file. 
4580#	If beyond this limit, Squid forwards the Range request as it is and 
4581#	the result is NOT cached.
4582#	
4583#	This is to stop a far ahead range request (lets say start at 17MB)
4584#	from making Squid fetch the whole object up to that point before
4585#	sending anything to the client.
4586#	
4587#	Multiple range_offset_limit lines may be specified, and they will 
4588#	be searched from top to bottom on each request until a match is found. 
4589#	The first match found will be used.  If no line matches a request, the 
4590#	default limit of 0 bytes will be used.
4591#	
4592#	'size' is the limit specified as a number of units.
4593#	
4594#	'units' specifies whether to use bytes, KB, MB, etc.
4595#	If no units are specified bytes are assumed.
4596#	
4597#	A size of 0 causes Squid to never fetch more than the
4598#	client requested. (default)
4599#	
4600#	A size of 'none' causes Squid to always fetch the object from the
4601#	beginning so it may cache the result. (2.0 style)
4602#	
4603#	'aclname' is the name of a defined ACL.
4604#	
4605#	NP: Using 'none' as the byte value here will override any quick_abort settings 
4606#	    that may otherwise apply to the range request. The range request will
4607#	    be fully fetched from start to finish regardless of the client
4608#	    actions. This affects bandwidth usage.
4609#Default:
4610# none
4611
4612#  TAG: minimum_expiry_time	(seconds)
4613#	The minimum caching time according to (Expires - Date)
4614#	headers Squid honors if the object can't be revalidated.
4615#	The default is 60 seconds.
4616#
4617#	In reverse proxy environments it might be desirable to honor
4618#	shorter object lifetimes. It is most likely better to make
4619#	your server return a meaningful Last-Modified header however.
4620#
4621#	In ESI environments where page fragments often have short
4622#	lifetimes, this will often be best set to 0.
4623#Default:
4624# minimum_expiry_time 60 seconds
4625
4626#  TAG: store_avg_object_size	(bytes)
4627#	Average object size, used to estimate number of objects your
4628#	cache can hold.  The default is 13 KB.
4629#
4630#	This is used to pre-seed the cache index memory allocation to
4631#	reduce expensive reallocate operations while handling clients
4632#	traffic. Too-large values may result in memory allocation during
4633#	peak traffic, too-small values will result in wasted memory.
4634#
4635#	Check the cache manager 'info' report metrics for the real
4636#	object sizes seen by your Squid before tuning this.
4637#Default:
4638# store_avg_object_size 13 KB
4639
4640#  TAG: store_objects_per_bucket
4641#	Target number of objects per bucket in the store hash table.
4642#	Lowering this value increases the total number of buckets and
4643#	also the storage maintenance rate.  The default is 20.
4644#Default:
4645# store_objects_per_bucket 20
4646
4647# HTTP OPTIONS
4648# -----------------------------------------------------------------------------
4649
4650#  TAG: request_header_max_size	(KB)
4651#	This specifies the maximum size for HTTP headers in a request.
4652#	Request headers are usually relatively small (about 512 bytes).
4653#	Placing a limit on the request header size will catch certain
4654#	bugs (for example with persistent connections) and possibly
4655#	buffer-overflow or denial-of-service attacks.
4656#Default:
4657# request_header_max_size 64 KB
4658
4659#  TAG: reply_header_max_size	(KB)
4660#	This specifies the maximum size for HTTP headers in a reply.
4661#	Reply headers are usually relatively small (about 512 bytes).
4662#	Placing a limit on the reply header size will catch certain
4663#	bugs (for example with persistent connections) and possibly
4664#	buffer-overflow or denial-of-service attacks.
4665#Default:
4666# reply_header_max_size 64 KB
4667
4668#  TAG: request_body_max_size	(bytes)
4669#	This specifies the maximum size for an HTTP request body.
4670#	In other words, the maximum size of a PUT/POST request.
4671#	A user who attempts to send a request with a body larger
4672#	than this limit receives an "Invalid Request" error message.
4673#	If you set this parameter to a zero (the default), there will
4674#	be no limit imposed.
4675#
4676#	See also client_request_buffer_max_size for an alternative
4677#	limitation on client uploads which can be configured.
4678#Default:
4679# No limit.
4680
4681#  TAG: client_request_buffer_max_size	(bytes)
4682#	This specifies the maximum buffer size of a client request.
4683#	It prevents squid eating too much memory when somebody uploads
4684#	a large file.
4685#Default:
4686# client_request_buffer_max_size 512 KB
4687
4688#  TAG: chunked_request_body_max_size	(bytes)
4689#	A broken or confused HTTP/1.1 client may send a chunked HTTP
4690#	request to Squid. Squid does not have full support for that
4691#	feature yet. To cope with such requests, Squid buffers the
4692#	entire request and then dechunks request body to create a
4693#	plain HTTP/1.0 request with a known content length. The plain
4694#	request is then used by the rest of Squid code as usual.
4695#
4696#	The option value specifies the maximum size of the buffer used
4697#	to hold the request before the conversion. If the chunked
4698#	request size exceeds the specified limit, the conversion
4699#	fails, and the client receives an "unsupported request" error,
4700#	as if dechunking was disabled.
4701#
4702#	Dechunking is enabled by default. To disable conversion of
4703#	chunked requests, set the maximum to zero.
4704#
4705#	Request dechunking feature and this option in particular are a
4706#	temporary hack. When chunking requests and responses are fully
4707#	supported, there will be no need to buffer a chunked request.
4708#Default:
4709# chunked_request_body_max_size 64 KB
4710
4711#  TAG: broken_posts
4712#	A list of ACL elements which, if matched, causes Squid to send
4713#	an extra CRLF pair after the body of a PUT/POST request.
4714#
4715#	Some HTTP servers has broken implementations of PUT/POST,
4716#	and rely on an extra CRLF pair sent by some WWW clients.
4717#
4718#	Quote from RFC2616 section 4.1 on this matter:
4719#
4720#	  Note: certain buggy HTTP/1.0 client implementations generate an
4721#	  extra CRLF's after a POST request. To restate what is explicitly
4722#	  forbidden by the BNF, an HTTP/1.1 client must not preface or follow
4723#	  a request with an extra CRLF.
4724#
4725#	This clause only supports fast acl types.
4726#	See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
4727#
4728#Example:
4729# acl buggy_server url_regex ^http://....
4730# broken_posts allow buggy_server
4731#Default:
4732# Obey RFC 2616.
4733
4734#  TAG: adaptation_uses_indirect_client	on|off
4735#	Controls whether the indirect client IP address (instead of the direct
4736#	client IP address) is passed to adaptation services.
4737#
4738#	See also: follow_x_forwarded_for adaptation_send_client_ip
4739#Default:
4740# adaptation_uses_indirect_client on
4741
4742#  TAG: via	on|off
4743#	If set (default), Squid will include a Via header in requests and
4744#	replies as required by RFC2616.
4745#Default:
4746# via on
4747
4748#  TAG: ie_refresh	on|off
4749#	Microsoft Internet Explorer up until version 5.5 Service
4750#	Pack 1 has an issue with transparent proxies, wherein it
4751#	is impossible to force a refresh.  Turning this on provides
4752#	a partial fix to the problem, by causing all IMS-REFRESH
4753#	requests from older IE versions to check the origin server
4754#	for fresh content.  This reduces hit ratio by some amount
4755#	(~10% in my experience), but allows users to actually get
4756#	fresh content when they want it.  Note because Squid
4757#	cannot tell if the user is using 5.5 or 5.5SP1, the behavior
4758#	of 5.5 is unchanged from old versions of Squid (i.e. a
4759#	forced refresh is impossible).  Newer versions of IE will,
4760#	hopefully, continue to have the new behavior and will be
4761#	handled based on that assumption.  This option defaults to
4762#	the old Squid behavior, which is better for hit ratios but
4763#	worse for clients using IE, if they need to be able to
4764#	force fresh content.
4765#Default:
4766# ie_refresh off
4767
4768#  TAG: vary_ignore_expire	on|off
4769#	Many HTTP servers supporting Vary gives such objects
4770#	immediate expiry time with no cache-control header
4771#	when requested by a HTTP/1.0 client. This option
4772#	enables Squid to ignore such expiry times until
4773#	HTTP/1.1 is fully implemented.
4774#
4775#	WARNING: If turned on this may eventually cause some
4776#	varying objects not intended for caching to get cached.
4777#Default:
4778# vary_ignore_expire off
4779
4780#  TAG: request_entities
4781#	Squid defaults to deny GET and HEAD requests with request entities,
4782#	as the meaning of such requests are undefined in the HTTP standard
4783#	even if not explicitly forbidden.
4784#
4785#	Set this directive to on if you have clients which insists
4786#	on sending request entities in GET or HEAD requests. But be warned
4787#	that there is server software (both proxies and web servers) which
4788#	can fail to properly process this kind of request which may make you
4789#	vulnerable to cache pollution attacks if enabled.
4790#Default:
4791# request_entities off
4792
4793#  TAG: request_header_access
4794#	Usage: request_header_access header_name allow|deny [!]aclname ...
4795#
4796#	WARNING: Doing this VIOLATES the HTTP standard.  Enabling
4797#	this feature could make you liable for problems which it
4798#	causes.
4799#
4800#	This option replaces the old 'anonymize_headers' and the
4801#	older 'http_anonymizer' option with something that is much
4802#	more configurable. A list of ACLs for each header name allows
4803#	removal of specific header fields under specific conditions.
4804#
4805#	This option only applies to outgoing HTTP request headers (i.e.,
4806#	headers sent by Squid to the next HTTP hop such as a cache peer
4807#	or an origin server). The option has no effect during cache hit
4808#	detection. The equivalent adaptation vectoring point in ICAP
4809#	terminology is post-cache REQMOD.
4810#
4811#	The option is applied to individual outgoing request header
4812#	fields. For each request header field F, Squid uses the first
4813#	qualifying sets of request_header_access rules:
4814#
4815#	    1. Rules with header_name equal to F's name.
4816#	    2. Rules with header_name 'Other', provided F's name is not
4817#	       on the hard-coded list of commonly used HTTP header names.
4818#	    3. Rules with header_name 'All'.
4819#
4820#	Within that qualifying rule set, rule ACLs are checked as usual.
4821#	If ACLs of an "allow" rule match, the header field is allowed to
4822#	go through as is. If ACLs of a "deny" rule match, the header is
4823#	removed and request_header_replace is then checked to identify
4824#	if the removed header has a replacement. If no rules within the
4825#	set have matching ACLs, the header field is left as is.
4826#
4827#	For example, to achieve the same behavior as the old
4828#	'http_anonymizer standard' option, you should use:
4829#
4830#		request_header_access From deny all
4831#		request_header_access Referer deny all
4832#		request_header_access User-Agent deny all
4833#
4834#	Or, to reproduce the old 'http_anonymizer paranoid' feature
4835#	you should use:
4836#
4837#		request_header_access Authorization allow all
4838#		request_header_access Proxy-Authorization allow all
4839#		request_header_access Cache-Control allow all
4840#		request_header_access Content-Length allow all
4841#		request_header_access Content-Type allow all
4842#		request_header_access Date allow all
4843#		request_header_access Host allow all
4844#		request_header_access If-Modified-Since allow all
4845#		request_header_access Pragma allow all
4846#		request_header_access Accept allow all
4847#		request_header_access Accept-Charset allow all
4848#		request_header_access Accept-Encoding allow all
4849#		request_header_access Accept-Language allow all
4850#		request_header_access Connection allow all
4851#		request_header_access All deny all
4852#
4853#	HTTP reply headers are controlled with the reply_header_access directive.
4854#
4855#	By default, all headers are allowed (no anonymizing is performed).
4856#Default:
4857# No limits.
4858
4859#  TAG: reply_header_access
4860#	Usage: reply_header_access header_name allow|deny [!]aclname ...
4861#
4862#	WARNING: Doing this VIOLATES the HTTP standard.  Enabling
4863#	this feature could make you liable for problems which it
4864#	causes.
4865#
4866#	This option only applies to reply headers, i.e., from the
4867#	server to the client.
4868#
4869#	This is the same as request_header_access, but in the other
4870#	direction. Please see request_header_access for detailed
4871#	documentation.
4872#
4873#	For example, to achieve the same behavior as the old
4874#	'http_anonymizer standard' option, you should use:
4875#
4876#		reply_header_access Server deny all
4877#		reply_header_access WWW-Authenticate deny all
4878#		reply_header_access Link deny all
4879#
4880#	Or, to reproduce the old 'http_anonymizer paranoid' feature
4881#	you should use:
4882#
4883#		reply_header_access Allow allow all
4884#		reply_header_access WWW-Authenticate allow all
4885#		reply_header_access Proxy-Authenticate allow all
4886#		reply_header_access Cache-Control allow all
4887#		reply_header_access Content-Encoding allow all
4888#		reply_header_access Content-Length allow all
4889#		reply_header_access Content-Type allow all
4890#		reply_header_access Date allow all
4891#		reply_header_access Expires allow all
4892#		reply_header_access Last-Modified allow all
4893#		reply_header_access Location allow all
4894#		reply_header_access Pragma allow all
4895#		reply_header_access Content-Language allow all
4896#		reply_header_access Retry-After allow all
4897#		reply_header_access Title allow all
4898#		reply_header_access Content-Disposition allow all
4899#		reply_header_access Connection allow all
4900#		reply_header_access All deny all
4901#
4902#	HTTP request headers are controlled with the request_header_access directive.
4903#
4904#	By default, all headers are allowed (no anonymizing is
4905#	performed).
4906#Default:
4907# No limits.
4908
4909#  TAG: request_header_replace
4910#	Usage:   request_header_replace header_name message
4911#	Example: request_header_replace User-Agent Nutscrape/1.0 (CP/M; 8-bit)
4912#
4913#	This option allows you to change the contents of headers
4914#	denied with request_header_access above, by replacing them
4915#	with some fixed string.
4916#
4917#	This only applies to request headers, not reply headers.
4918#
4919#	By default, headers are removed if denied.
4920#Default:
4921# none
4922
4923#  TAG: reply_header_replace
4924#        Usage:   reply_header_replace header_name message
4925#        Example: reply_header_replace Server Foo/1.0
4926#
4927#        This option allows you to change the contents of headers
4928#        denied with reply_header_access above, by replacing them
4929#        with some fixed string.
4930#
4931#        This only applies to reply headers, not request headers.
4932#
4933#        By default, headers are removed if denied.
4934#Default:
4935# none
4936
4937#  TAG: request_header_add
4938#	Usage:   request_header_add field-name field-value acl1 [acl2] ...
4939#	Example: request_header_add X-Client-CA "CA=%ssl::>cert_issuer" all
4940#
4941#	This option adds header fields to outgoing HTTP requests (i.e.,
4942#	request headers sent by Squid to the next HTTP hop such as a
4943#	cache peer or an origin server). The option has no effect during
4944#	cache hit detection. The equivalent adaptation vectoring point
4945#	in ICAP terminology is post-cache REQMOD.
4946#
4947#	Field-name is a token specifying an HTTP header name. If a
4948#	standard HTTP header name is used, Squid does not check whether
4949#	the new header conflicts with any existing headers or violates
4950#	HTTP rules. If the request to be modified already contains a
4951#	field with the same name, the old field is preserved but the
4952#	header field values are not merged.
4953#
4954#	Field-value is either a token or a quoted string. If quoted
4955#	string format is used, then the surrounding quotes are removed
4956#	while escape sequences and %macros are processed.
4957#
4958#	In theory, all of the logformat codes can be used as %macros.
4959#	However, unlike logging (which happens at the very end of
4960#	transaction lifetime), the transaction may not yet have enough
4961#	information to expand a macro when the new header value is needed.
4962#	And some information may already be available to Squid but not yet
4963#	committed where the macro expansion code can access it (report
4964#	such instances!). The macro will be expanded into a single dash
4965#	('-') in such cases. Not all macros have been tested.
4966#
4967#	One or more Squid ACLs may be specified to restrict header
4968#	injection to matching requests. As always in squid.conf, all
4969#	ACLs in an option ACL list must be satisfied for the insertion
4970#	to happen. The request_header_add option supports fast ACLs
4971#	only.
4972#Default:
4973# none
4974
4975#  TAG: note
4976#	This option used to log custom information about the master
4977#	transaction. For example, an admin may configure Squid to log
4978#	which "user group" the transaction belongs to, where "user group"
4979#	will be determined based on a set of ACLs and not [just]
4980#	authentication information.
4981#	Values of key/value pairs can be logged using %{key}note macros:
4982#
4983#	    note key value acl ...
4984#	    logformat myFormat ... %{key}note ...
4985#Default:
4986# none
4987
4988#  TAG: relaxed_header_parser	on|off|warn
4989#	In the default "on" setting Squid accepts certain forms
4990#	of non-compliant HTTP messages where it is unambiguous
4991#	what the sending application intended even if the message
4992#	is not correctly formatted. The messages is then normalized
4993#	to the correct form when forwarded by Squid.
4994#
4995#	If set to "warn" then a warning will be emitted in cache.log
4996#	each time such HTTP error is encountered.
4997#
4998#	If set to "off" then such HTTP errors will cause the request
4999#	or response to be rejected.
5000#Default:
5001# relaxed_header_parser on
5002
5003# TIMEOUTS
5004# -----------------------------------------------------------------------------
5005
5006#  TAG: forward_timeout	time-units
5007#	This parameter specifies how long Squid should at most attempt in
5008#	finding a forwarding path for the request before giving up.
5009#Default:
5010# forward_timeout 4 minutes
5011
5012#  TAG: connect_timeout	time-units
5013#	This parameter specifies how long to wait for the TCP connect to
5014#	the requested server or peer to complete before Squid should
5015#	attempt to find another path where to forward the request.
5016#Default:
5017# connect_timeout 1 minute
5018
5019#  TAG: peer_connect_timeout	time-units
5020#	This parameter specifies how long to wait for a pending TCP
5021#	connection to a peer cache.  The default is 30 seconds.   You
5022#	may also set different timeout values for individual neighbors
5023#	with the 'connect-timeout' option on a 'cache_peer' line.
5024#Default:
5025# peer_connect_timeout 30 seconds
5026
5027#  TAG: read_timeout	time-units
5028#	The read_timeout is applied on server-side connections.  After
5029#	each successful read(), the timeout will be extended by this
5030#	amount.  If no data is read again after this amount of time,
5031#	the request is aborted and logged with ERR_READ_TIMEOUT.  The
5032#	default is 15 minutes.
5033#Default:
5034# read_timeout 15 minutes
5035
5036#  TAG: write_timeout	time-units
5037#	This timeout is tracked for all connections that have data
5038#	available for writing and are waiting for the socket to become
5039#	ready. After each successful write, the timeout is extended by
5040#	the configured amount. If Squid has data to write but the
5041#	connection is not ready for the configured duration, the
5042#	transaction associated with the connection is terminated. The
5043#	default is 15 minutes.
5044#Default:
5045# write_timeout 15 minutes
5046
5047#  TAG: request_timeout
5048#	How long to wait for complete HTTP request headers after initial
5049#	connection establishment.
5050#Default:
5051# request_timeout 5 minutes
5052
5053#  TAG: client_idle_pconn_timeout
5054#	How long to wait for the next HTTP request on a persistent
5055#	client connection after the previous request completes.
5056#Default:
5057# client_idle_pconn_timeout 2 minutes
5058
5059#  TAG: client_lifetime	time-units
5060#	The maximum amount of time a client (browser) is allowed to
5061#	remain connected to the cache process.  This protects the Cache
5062#	from having a lot of sockets (and hence file descriptors) tied up
5063#	in a CLOSE_WAIT state from remote clients that go away without
5064#	properly shutting down (either because of a network failure or
5065#	because of a poor client implementation).  The default is one
5066#	day, 1440 minutes.
5067#
5068#	NOTE:  The default value is intended to be much larger than any
5069#	client would ever need to be connected to your cache.  You
5070#	should probably change client_lifetime only as a last resort.
5071#	If you seem to have many client connections tying up
5072#	filedescriptors, we recommend first tuning the read_timeout,
5073#	request_timeout, persistent_request_timeout and quick_abort values.
5074#Default:
5075# client_lifetime 1 day
5076
5077#  TAG: half_closed_clients
5078#	Some clients may shutdown the sending side of their TCP
5079#	connections, while leaving their receiving sides open.	Sometimes,
5080#	Squid can not tell the difference between a half-closed and a
5081#	fully-closed TCP connection.
5082#
5083#	By default, Squid will immediately close client connections when
5084#	read(2) returns "no more data to read."
5085#
5086#	Change this option to 'on' and Squid will keep open connections
5087#	until a read(2) or write(2) on the socket returns an error.
5088#	This may show some benefits for reverse proxies. But if not
5089#	it is recommended to leave OFF.
5090#Default:
5091# half_closed_clients off
5092
5093#  TAG: server_idle_pconn_timeout
5094#	Timeout for idle persistent connections to servers and other
5095#	proxies.
5096#Default:
5097# server_idle_pconn_timeout 1 minute
5098
5099#  TAG: ident_timeout
5100#	Maximum time to wait for IDENT lookups to complete.
5101#
5102#	If this is too high, and you enabled IDENT lookups from untrusted
5103#	users, you might be susceptible to denial-of-service by having
5104#	many ident requests going at once.
5105#Default:
5106# ident_timeout 10 seconds
5107
5108#  TAG: shutdown_lifetime	time-units
5109#	When SIGTERM or SIGHUP is received, the cache is put into
5110#	"shutdown pending" mode until all active sockets are closed.
5111#	This value is the lifetime to set for all open descriptors
5112#	during shutdown mode.  Any active clients after this many
5113#	seconds will receive a 'timeout' message.
5114#Default:
5115# shutdown_lifetime 30 seconds
5116
5117# ADMINISTRATIVE PARAMETERS
5118# -----------------------------------------------------------------------------
5119
5120#  TAG: cache_mgr
5121#	Email-address of local cache manager who will receive
5122#	mail if the cache dies.  The default is "webmaster".
5123#Default:
5124# cache_mgr webmaster
5125
5126#  TAG: mail_from
5127#	From: email-address for mail sent when the cache dies.
5128#	The default is to use 'squid@unique_hostname'.
5129#
5130#	See also: unique_hostname directive.
5131#Default:
5132# none
5133
5134#  TAG: mail_program
5135#	Email program used to send mail if the cache dies.
5136#	The default is "mail". The specified program must comply
5137#	with the standard Unix mail syntax:
5138#	  mail-program recipient < mailfile
5139#
5140#	Optional command line options can be specified.
5141#Default:
5142# mail_program mail
5143
5144#  TAG: cache_effective_user
5145#	If you start Squid as root, it will change its effective/real
5146#	UID/GID to the user specified below.  The default is to change
5147#	to UID of proxy.
5148#	see also; cache_effective_group
5149#Default:
5150# cache_effective_user proxy
5151
5152#  TAG: cache_effective_group
5153#	Squid sets the GID to the effective user's default group ID
5154#	(taken from the password file) and supplementary group list
5155#	from the groups membership.
5156#
5157#	If you want Squid to run with a specific GID regardless of
5158#	the group memberships of the effective user then set this
5159#	to the group (or GID) you want Squid to run as. When set
5160#	all other group privileges of the effective user are ignored
5161#	and only this GID is effective. If Squid is not started as
5162#	root the user starting Squid MUST be member of the specified
5163#	group.
5164#
5165#	This option is not recommended by the Squid Team.
5166#	Our preference is for administrators to configure a secure
5167#	user account for squid with UID/GID matching system policies.
5168#Default:
5169# Use system group memberships of the cache_effective_user account
5170
5171#  TAG: httpd_suppress_version_string	on|off
5172#	Suppress Squid version string info in HTTP headers and HTML error pages.
5173#Default:
5174# httpd_suppress_version_string off
5175
5176#  TAG: visible_hostname
5177#	If you want to present a special hostname in error messages, etc,
5178#	define this.  Otherwise, the return value of gethostname()
5179#	will be used. If you have multiple caches in a cluster and
5180#	get errors about IP-forwarding you must set them to have individual
5181#	names with this setting.
5182#Default:
5183# Automatically detect the system host name
5184
5185#  TAG: unique_hostname
5186#	If you want to have multiple machines with the same
5187#	'visible_hostname' you must give each machine a different
5188#	'unique_hostname' so forwarding loops can be detected.
5189#Default:
5190# Copy the value from visible_hostname
5191
5192#  TAG: hostname_aliases
5193#	A list of other DNS names your cache has.
5194#Default:
5195# none
5196
5197#  TAG: umask
5198#	Minimum umask which should be enforced while the proxy
5199#	is running, in addition to the umask set at startup.
5200#
5201#	For a traditional octal representation of umasks, start
5202#        your value with 0.
5203#Default:
5204# umask 027
5205
5206# OPTIONS FOR THE CACHE REGISTRATION SERVICE
5207# -----------------------------------------------------------------------------
5208#
5209#	This section contains parameters for the (optional) cache
5210#	announcement service.  This service is provided to help
5211#	cache administrators locate one another in order to join or
5212#	create cache hierarchies.
5213#
5214#	An 'announcement' message is sent (via UDP) to the registration
5215#	service by Squid.  By default, the announcement message is NOT
5216#	SENT unless you enable it with 'announce_period' below.
5217#
5218#	The announcement message includes your hostname, plus the
5219#	following information from this configuration file:
5220#
5221#		http_port
5222#		icp_port
5223#		cache_mgr
5224#
5225#	All current information is processed regularly and made
5226#	available on the Web at http://www.ircache.net/Cache/Tracker/.
5227
5228#  TAG: announce_period
5229#	This is how frequently to send cache announcements.
5230#
5231#	To enable announcing your cache, just set an announce period.
5232#
5233#	Example:
5234#		announce_period 1 day
5235#Default:
5236# Announcement messages disabled.
5237
5238#  TAG: announce_host
5239#	Set the hostname where announce registration messages will be sent.
5240#
5241#	See also announce_port and announce_file
5242#Default:
5243# announce_host tracker.ircache.net
5244
5245#  TAG: announce_file
5246#	The contents of this file will be included in the announce
5247#	registration messages.
5248#Default:
5249# none
5250
5251#  TAG: announce_port
5252#	Set the port where announce registration messages will be sent.
5253#
5254#	See also announce_host and announce_file
5255#Default:
5256# announce_port 3131
5257
5258# HTTPD-ACCELERATOR OPTIONS
5259# -----------------------------------------------------------------------------
5260
5261#  TAG: httpd_accel_surrogate_id
5262#	Surrogates (http://www.esi.org/architecture_spec_1.0.html)
5263#	need an identification token to allow control targeting. Because
5264#	a farm of surrogates may all perform the same tasks, they may share
5265#	an identification token.
5266#Default:
5267# visible_hostname is used if no specific ID is set.
5268
5269#  TAG: http_accel_surrogate_remote	on|off
5270#	Remote surrogates (such as those in a CDN) honour the header
5271#	"Surrogate-Control: no-store-remote".
5272#
5273#	Set this to on to have squid behave as a remote surrogate.
5274#Default:
5275# http_accel_surrogate_remote off
5276
5277#  TAG: esi_parser	libxml2|expat|custom
5278#	ESI markup is not strictly XML compatible. The custom ESI parser
5279#	will give higher performance, but cannot handle non ASCII character
5280#	encodings.
5281#Default:
5282# esi_parser custom
5283
5284# DELAY POOL PARAMETERS
5285# -----------------------------------------------------------------------------
5286
5287#  TAG: delay_pools
5288#	This represents the number of delay pools to be used.  For example,
5289#	if you have one class 2 delay pool and one class 3 delays pool, you
5290#	have a total of 2 delay pools.
5291#
5292#	See also delay_parameters, delay_class, delay_access for pool
5293#	configuration details.
5294#Default:
5295# delay_pools 0
5296
5297#  TAG: delay_class
5298#	This defines the class of each delay pool.  There must be exactly one
5299#	delay_class line for each delay pool.  For example, to define two
5300#	delay pools, one of class 2 and one of class 3, the settings above
5301#	and here would be:
5302#
5303#	Example:
5304#	    delay_pools 4      # 4 delay pools
5305#	    delay_class 1 2    # pool 1 is a class 2 pool
5306#	    delay_class 2 3    # pool 2 is a class 3 pool
5307#	    delay_class 3 4    # pool 3 is a class 4 pool
5308#	    delay_class 4 5    # pool 4 is a class 5 pool
5309#
5310#	The delay pool classes are:
5311#
5312#		class 1		Everything is limited by a single aggregate
5313#				bucket.
5314#
5315#		class 2 	Everything is limited by a single aggregate
5316#				bucket as well as an "individual" bucket chosen
5317#				from bits 25 through 32 of the IPv4 address.
5318#
5319#		class 3		Everything is limited by a single aggregate
5320#				bucket as well as a "network" bucket chosen
5321#				from bits 17 through 24 of the IP address and a
5322#				"individual" bucket chosen from bits 17 through
5323#				32 of the IPv4 address.
5324#
5325#		class 4		Everything in a class 3 delay pool, with an
5326#				additional limit on a per user basis. This
5327#				only takes effect if the username is established
5328#				in advance - by forcing authentication in your
5329#				http_access rules.
5330#
5331#		class 5		Requests are grouped according their tag (see
5332#				external_acl's tag= reply).
5333#
5334#
5335#	Each pool also requires a delay_parameters directive to configure the pool size
5336#	and speed limits used whenever the pool is applied to a request. Along with
5337#	a set of delay_access directives to determine when it is used.
5338#
5339#	NOTE: If an IP address is a.b.c.d
5340#		-> bits 25 through 32 are "d"
5341#		-> bits 17 through 24 are "c"
5342#		-> bits 17 through 32 are "c * 256 + d"
5343#
5344#	NOTE-2: Due to the use of bitmasks in class 2,3,4 pools they only apply to
5345#		IPv4 traffic. Class 1 and 5 pools may be used with IPv6 traffic.
5346#
5347#	This clause only supports fast acl types.
5348#	See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
5349#
5350#	See also delay_parameters and delay_access.
5351#Default:
5352# none
5353
5354#  TAG: delay_access
5355#	This is used to determine which delay pool a request falls into.
5356#
5357#	delay_access is sorted per pool and the matching starts with pool 1,
5358#	then pool 2, ..., and finally pool N. The first delay pool where the
5359#	request is allowed is selected for the request. If it does not allow
5360#	the request to any pool then the request is not delayed (default).
5361#
5362#	For example, if you want some_big_clients in delay
5363#	pool 1 and lotsa_little_clients in delay pool 2:
5364#
5365#		delay_access 1 allow some_big_clients
5366#		delay_access 1 deny all
5367#		delay_access 2 allow lotsa_little_clients
5368#		delay_access 2 deny all
5369#		delay_access 3 allow authenticated_clients
5370#
5371#	See also delay_parameters and delay_class.
5372#
5373#Default:
5374# Deny using the pool, unless allow rules exist in squid.conf for the pool.
5375
5376#  TAG: delay_parameters
5377#	This defines the parameters for a delay pool.  Each delay pool has
5378#	a number of "buckets" associated with it, as explained in the
5379#	description of delay_class.
5380#
5381#	For a class 1 delay pool, the syntax is:
5382#		delay_pools pool 1
5383#		delay_parameters pool aggregate
5384#
5385#	For a class 2 delay pool:
5386#		delay_pools pool 2
5387#		delay_parameters pool aggregate individual
5388#
5389#	For a class 3 delay pool:
5390#		delay_pools pool 3
5391#		delay_parameters pool aggregate network individual
5392#
5393#	For a class 4 delay pool:
5394#		delay_pools pool 4
5395#		delay_parameters pool aggregate network individual user
5396#
5397#	For a class 5 delay pool:
5398#		delay_pools pool 5
5399#		delay_parameters pool tagrate
5400#
5401#	The option variables are:
5402#
5403#		pool		a pool number - ie, a number between 1 and the
5404#				number specified in delay_pools as used in
5405#				delay_class lines.
5406#
5407#		aggregate	the speed limit parameters for the aggregate bucket
5408#				(class 1, 2, 3).
5409#
5410#		individual	the speed limit parameters for the individual
5411#				buckets (class 2, 3).
5412#
5413#		network		the speed limit parameters for the network buckets
5414#				(class 3).
5415#
5416#		user		the speed limit parameters for the user buckets
5417#				(class 4).
5418#
5419#		tagrate		the speed limit parameters for the tag buckets
5420#				(class 5).
5421#
5422#	A pair of delay parameters is written restore/maximum, where restore is
5423#	the number of bytes (not bits - modem and network speeds are usually
5424#	quoted in bits) per second placed into the bucket, and maximum is the
5425#	maximum number of bytes which can be in the bucket at any time.
5426#
5427#	There must be one delay_parameters line for each delay pool.
5428#
5429#
5430#	For example, if delay pool number 1 is a class 2 delay pool as in the
5431#	above example, and is being used to strictly limit each host to 64Kbit/sec
5432#	(plus overheads), with no overall limit, the line is:
5433#
5434#		delay_parameters 1 -1/-1 8000/8000
5435#
5436#	Note that 8 x 8000 KByte/sec -> 64Kbit/sec.
5437#
5438#	Note that the figure -1 is used to represent "unlimited".
5439#
5440#
5441#	And, if delay pool number 2 is a class 3 delay pool as in the above
5442#	example, and you want to limit it to a total of 256Kbit/sec (strict limit)
5443#	with each 8-bit network permitted 64Kbit/sec (strict limit) and each
5444#	individual host permitted 4800bit/sec with a bucket maximum size of 64Kbits
5445#	to permit a decent web page to be downloaded at a decent speed
5446#	(if the network is not being limited due to overuse) but slow down
5447#	large downloads more significantly:
5448#
5449#		delay_parameters 2 32000/32000 8000/8000 600/8000
5450#
5451#	Note that 8 x 32000 KByte/sec -> 256Kbit/sec.
5452#		  8 x  8000 KByte/sec ->  64Kbit/sec.
5453#		  8 x   600 Byte/sec  -> 4800bit/sec.
5454#
5455#
5456#	Finally, for a class 4 delay pool as in the example - each user will
5457#	be limited to 128Kbits/sec no matter how many workstations they are logged into.:
5458#
5459#		delay_parameters 4 32000/32000 8000/8000 600/64000 16000/16000
5460#
5461#
5462#	See also delay_class and delay_access.
5463#
5464#Default:
5465# none
5466
5467#  TAG: delay_initial_bucket_level	(percent, 0-100)
5468#	The initial bucket percentage is used to determine how much is put
5469#	in each bucket when squid starts, is reconfigured, or first notices
5470#	a host accessing it (in class 2 and class 3, individual hosts and
5471#	networks only have buckets associated with them once they have been
5472#	"seen" by squid).
5473#Default:
5474# delay_initial_bucket_level 50
5475
5476# CLIENT DELAY POOL PARAMETERS
5477# -----------------------------------------------------------------------------
5478
5479#  TAG: client_delay_pools
5480#	This option specifies the number of client delay pools used. It must
5481#	preceed other client_delay_* options.
5482#
5483#	Example:
5484#		client_delay_pools 2
5485#
5486#	See also client_delay_parameters and client_delay_access.
5487#Default:
5488# client_delay_pools 0
5489
5490#  TAG: client_delay_initial_bucket_level	(percent, 0-no_limit)
5491#	This option determines the initial bucket size as a percentage of
5492#	max_bucket_size from client_delay_parameters. Buckets are created
5493#	at the time of the "first" connection from the matching IP. Idle
5494#	buckets are periodically deleted up.
5495#
5496#	You can specify more than 100 percent but note that such "oversized"
5497#	buckets are not refilled until their size goes down to max_bucket_size
5498#	from client_delay_parameters.
5499#
5500#	Example:
5501#		client_delay_initial_bucket_level 50
5502#Default:
5503# client_delay_initial_bucket_level 50
5504
5505#  TAG: client_delay_parameters
5506#
5507#	This option configures client-side bandwidth limits using the
5508#	following format:
5509#
5510#	    client_delay_parameters pool speed_limit max_bucket_size
5511#
5512#	pool is an integer ID used for client_delay_access matching.
5513#
5514#	speed_limit is bytes added to the bucket per second.
5515#
5516#	max_bucket_size is the maximum size of a bucket, enforced after any
5517#	speed_limit additions.
5518#
5519#	Please see the delay_parameters option for more information and
5520#	examples.
5521#
5522#	Example:
5523#		client_delay_parameters 1 1024 2048
5524#		client_delay_parameters 2 51200 16384
5525#
5526#	See also client_delay_access.
5527#
5528#Default:
5529# none
5530
5531#  TAG: client_delay_access
5532#	This option determines the client-side delay pool for the
5533#	request:
5534#
5535#	    client_delay_access pool_ID allow|deny acl_name
5536#
5537#	All client_delay_access options are checked in their pool ID
5538#	order, starting with pool 1. The first checked pool with allowed
5539#	request is selected for the request. If no ACL matches or there
5540#	are no client_delay_access options, the request bandwidth is not
5541#	limited.
5542#
5543#	The ACL-selected pool is then used to find the
5544#	client_delay_parameters for the request. Client-side pools are
5545#	not used to aggregate clients. Clients are always aggregated
5546#	based on their source IP addresses (one bucket per source IP).
5547#
5548#	This clause only supports fast acl types.
5549#	See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
5550#	Additionally, only the client TCP connection details are available.
5551#	ACLs testing HTTP properties will not work.
5552#
5553#	Please see delay_access for more examples.
5554#
5555#	Example:
5556#		client_delay_access 1 allow low_rate_network
5557#		client_delay_access 2 allow vips_network
5558#
5559#
5560#	See also client_delay_parameters and client_delay_pools.
5561#Default:
5562# Deny use of the pool, unless allow rules exist in squid.conf for the pool.
5563
5564# WCCPv1 AND WCCPv2 CONFIGURATION OPTIONS
5565# -----------------------------------------------------------------------------
5566
5567#  TAG: wccp_router
5568#	Use this option to define your WCCP ``home'' router for
5569#	Squid.
5570#
5571#	wccp_router supports a single WCCP(v1) router
5572#
5573#	wccp2_router supports multiple WCCPv2 routers
5574#
5575#	only one of the two may be used at the same time and defines
5576#	which version of WCCP to use.
5577#Default:
5578# WCCP disabled.
5579
5580#  TAG: wccp2_router
5581#	Use this option to define your WCCP ``home'' router for
5582#	Squid.
5583#
5584#	wccp_router supports a single WCCP(v1) router
5585#
5586#	wccp2_router supports multiple WCCPv2 routers
5587#
5588#	only one of the two may be used at the same time and defines
5589#	which version of WCCP to use.
5590#Default:
5591# WCCPv2 disabled.
5592
5593#  TAG: wccp_version
5594#	This directive is only relevant if you need to set up WCCP(v1)
5595#	to some very old and end-of-life Cisco routers. In all other
5596#	setups it must be left unset or at the default setting.
5597#	It defines an internal version in the WCCP(v1) protocol,
5598#	with version 4 being the officially documented protocol.
5599#
5600#	According to some users, Cisco IOS 11.2 and earlier only
5601#	support WCCP version 3.  If you're using that or an earlier
5602#	version of IOS, you may need to change this value to 3, otherwise
5603#	do not specify this parameter.
5604#Default:
5605# wccp_version 4
5606
5607#  TAG: wccp2_rebuild_wait
5608#	If this is enabled Squid will wait for the cache dir rebuild to finish
5609#	before sending the first wccp2 HereIAm packet
5610#Default:
5611# wccp2_rebuild_wait on
5612
5613#  TAG: wccp2_forwarding_method
5614#	WCCP2 allows the setting of forwarding methods between the
5615#	router/switch and the cache.  Valid values are as follows:
5616#
5617#	gre - GRE encapsulation (forward the packet in a GRE/WCCP tunnel)
5618#	l2  - L2 redirect (forward the packet using Layer 2/MAC rewriting)
5619#
5620#	Currently (as of IOS 12.4) cisco routers only support GRE.
5621#	Cisco switches only support the L2 redirect assignment method.
5622#Default:
5623# wccp2_forwarding_method gre
5624
5625#  TAG: wccp2_return_method
5626#	WCCP2 allows the setting of return methods between the
5627#	router/switch and the cache for packets that the cache
5628#	decides not to handle.  Valid values are as follows:
5629#
5630#	gre - GRE encapsulation (forward the packet in a GRE/WCCP tunnel)
5631#	l2  - L2 redirect (forward the packet using Layer 2/MAC rewriting)
5632#
5633#	Currently (as of IOS 12.4) cisco routers only support GRE.
5634#	Cisco switches only support the L2 redirect assignment.
5635#
5636#	If the "ip wccp redirect exclude in" command has been
5637#	enabled on the cache interface, then it is still safe for
5638#	the proxy server to use a l2 redirect method even if this
5639#	option is set to GRE.
5640#Default:
5641# wccp2_return_method gre
5642
5643#  TAG: wccp2_assignment_method
5644#	WCCP2 allows the setting of methods to assign the WCCP hash
5645#	Valid values are as follows:
5646#
5647#	hash - Hash assignment
5648#	mask - Mask assignment
5649#
5650#	As a general rule, cisco routers support the hash assignment method
5651#	and cisco switches support the mask assignment method.
5652#Default:
5653# wccp2_assignment_method hash
5654
5655#  TAG: wccp2_service
5656#	WCCP2 allows for multiple traffic services. There are two
5657#	types: "standard" and "dynamic". The standard type defines
5658#	one service id - http (id 0). The dynamic service ids can be from
5659#	51 to 255 inclusive.  In order to use a dynamic service id
5660#	one must define the type of traffic to be redirected; this is done
5661#	using the wccp2_service_info option.
5662#
5663#	The "standard" type does not require a wccp2_service_info option,
5664#	just specifying the service id will suffice.
5665#
5666#	MD5 service authentication can be enabled by adding
5667#	"password=<password>" to the end of this service declaration.
5668#
5669#	Examples:
5670#
5671#	wccp2_service standard 0	# for the 'web-cache' standard service
5672#	wccp2_service dynamic 80	# a dynamic service type which will be
5673#					# fleshed out with subsequent options.
5674#	wccp2_service standard 0 password=foo
5675#Default:
5676# Use the 'web-cache' standard service.
5677
5678#  TAG: wccp2_service_info
5679#	Dynamic WCCPv2 services require further information to define the
5680#	traffic you wish to have diverted.
5681#
5682#	The format is:
5683#
5684#	wccp2_service_info <id> protocol=<protocol> flags=<flag>,<flag>..
5685#	    priority=<priority> ports=<port>,<port>..
5686#
5687#	The relevant WCCPv2 flags:
5688#	+ src_ip_hash, dst_ip_hash
5689#	+ source_port_hash, dst_port_hash
5690#	+ src_ip_alt_hash, dst_ip_alt_hash
5691#	+ src_port_alt_hash, dst_port_alt_hash
5692#	+ ports_source
5693#
5694#	The port list can be one to eight entries.
5695#
5696#	Example:
5697#
5698#	wccp2_service_info 80 protocol=tcp flags=src_ip_hash,ports_source
5699#	    priority=240 ports=80
5700#
5701#	Note: the service id must have been defined by a previous
5702#	'wccp2_service dynamic <id>' entry.
5703#Default:
5704# none
5705
5706#  TAG: wccp2_weight
5707#	Each cache server gets assigned a set of the destination
5708#	hash proportional to their weight.
5709#Default:
5710# wccp2_weight 10000
5711
5712#  TAG: wccp_address
5713#	Use this option if you require WCCPv2 to use a specific
5714#	interface address.
5715#
5716#	The default behavior is to not bind to any specific address.
5717#Default:
5718# Address selected by the operating system.
5719
5720#  TAG: wccp2_address
5721#	Use this option if you require WCCP to use a specific
5722#	interface address.
5723#
5724#	The default behavior is to not bind to any specific address.
5725#Default:
5726# Address selected by the operating system.
5727
5728# PERSISTENT CONNECTION HANDLING
5729# -----------------------------------------------------------------------------
5730#
5731# Also see "pconn_timeout" in the TIMEOUTS section
5732
5733#  TAG: client_persistent_connections
5734#	Persistent connection support for clients.
5735#	Squid uses persistent connections (when allowed). You can use
5736#	this option to disable persistent connections with clients.
5737#Default:
5738# client_persistent_connections on
5739
5740#  TAG: server_persistent_connections
5741#	Persistent connection support for servers.
5742#	Squid uses persistent connections (when allowed). You can use
5743#	this option to disable persistent connections with servers.
5744#Default:
5745# server_persistent_connections on
5746
5747#  TAG: persistent_connection_after_error
5748#	With this directive the use of persistent connections after
5749#	HTTP errors can be disabled. Useful if you have clients
5750#	who fail to handle errors on persistent connections proper.
5751#Default:
5752# persistent_connection_after_error on
5753
5754#  TAG: detect_broken_pconn
5755#	Some servers have been found to incorrectly signal the use
5756#	of HTTP/1.0 persistent connections even on replies not
5757#	compatible, causing significant delays. This server problem
5758#	has mostly been seen on redirects.
5759#
5760#	By enabling this directive Squid attempts to detect such
5761#	broken replies and automatically assume the reply is finished
5762#	after 10 seconds timeout.
5763#Default:
5764# detect_broken_pconn off
5765
5766# CACHE DIGEST OPTIONS
5767# -----------------------------------------------------------------------------
5768
5769#  TAG: digest_generation
5770#	This controls whether the server will generate a Cache Digest
5771#	of its contents.  By default, Cache Digest generation is
5772#	enabled if Squid is compiled with --enable-cache-digests defined.
5773#Default:
5774# digest_generation on
5775
5776#  TAG: digest_bits_per_entry
5777#	This is the number of bits of the server's Cache Digest which
5778#	will be associated with the Digest entry for a given HTTP
5779#	Method and URL (public key) combination.  The default is 5.
5780#Default:
5781# digest_bits_per_entry 5
5782
5783#  TAG: digest_rebuild_period	(seconds)
5784#	This is the wait time between Cache Digest rebuilds.
5785#Default:
5786# digest_rebuild_period 1 hour
5787
5788#  TAG: digest_rewrite_period	(seconds)
5789#	This is the wait time between Cache Digest writes to
5790#	disk.
5791#Default:
5792# digest_rewrite_period 1 hour
5793
5794#  TAG: digest_swapout_chunk_size	(bytes)
5795#	This is the number of bytes of the Cache Digest to write to
5796#	disk at a time.  It defaults to 4096 bytes (4KB), the Squid
5797#	default swap page.
5798#Default:
5799# digest_swapout_chunk_size 4096 bytes
5800
5801#  TAG: digest_rebuild_chunk_percentage	(percent, 0-100)
5802#	This is the percentage of the Cache Digest to be scanned at a
5803#	time.  By default it is set to 10% of the Cache Digest.
5804#Default:
5805# digest_rebuild_chunk_percentage 10
5806
5807# SNMP OPTIONS
5808# -----------------------------------------------------------------------------
5809
5810#  TAG: snmp_port
5811#	The port number where Squid listens for SNMP requests. To enable
5812#	SNMP support set this to a suitable port number. Port number
5813#	3401 is often used for the Squid SNMP agent. By default it's
5814#	set to "0" (disabled)
5815#
5816#	Example:
5817#		snmp_port 3401
5818#Default:
5819# SNMP disabled.
5820
5821#  TAG: snmp_access
5822#	Allowing or denying access to the SNMP port.
5823#
5824#	All access to the agent is denied by default.
5825#	usage:
5826#
5827#	snmp_access allow|deny [!]aclname ...
5828#
5829#	This clause only supports fast acl types.
5830#	See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
5831#
5832#Example:
5833# snmp_access allow snmppublic localhost
5834# snmp_access deny all
5835#Default:
5836# Deny, unless rules exist in squid.conf.
5837
5838#  TAG: snmp_incoming_address
5839#	Just like 'udp_incoming_address', but for the SNMP port.
5840#
5841#	snmp_incoming_address	is used for the SNMP socket receiving
5842#				messages from SNMP agents.
5843#
5844#	The default snmp_incoming_address is to listen on all
5845#	available network interfaces.
5846#Default:
5847# Accept SNMP packets from all machine interfaces.
5848
5849#  TAG: snmp_outgoing_address
5850#	Just like 'udp_outgoing_address', but for the SNMP port.
5851#
5852#	snmp_outgoing_address	is used for SNMP packets returned to SNMP
5853#				agents.
5854#
5855#	If snmp_outgoing_address is not set it will use the same socket
5856#	as snmp_incoming_address. Only change this if you want to have
5857#	SNMP replies sent using another address than where this Squid
5858#	listens for SNMP queries.
5859#
5860#	NOTE, snmp_incoming_address and snmp_outgoing_address can not have
5861#	the same value since they both use the same port.
5862#Default:
5863# Use snmp_incoming_address or an address selected by the operating system.
5864
5865# ICP OPTIONS
5866# -----------------------------------------------------------------------------
5867
5868#  TAG: icp_port
5869#	The port number where Squid sends and receives ICP queries to
5870#	and from neighbor caches.  The standard UDP port for ICP is 3130.
5871#
5872#	Example:
5873#		icp_port 3130
5874#Default:
5875# ICP disabled.
5876
5877#  TAG: htcp_port
5878#	The port number where Squid sends and receives HTCP queries to
5879#	and from neighbor caches.  To turn it on you want to set it to
5880#	4827.
5881#
5882#	Example:
5883#		htcp_port 4827
5884#Default:
5885# HTCP disabled.
5886
5887#  TAG: log_icp_queries	on|off
5888#	If set, ICP queries are logged to access.log. You may wish
5889#	do disable this if your ICP load is VERY high to speed things
5890#	up or to simplify log analysis.
5891#Default:
5892# log_icp_queries on
5893
5894#  TAG: udp_incoming_address
5895#	udp_incoming_address	is used for UDP packets received from other
5896#				caches.
5897#
5898#	The default behavior is to not bind to any specific address.
5899#
5900#	Only change this if you want to have all UDP queries received on
5901#	a specific interface/address.
5902#
5903#	NOTE: udp_incoming_address is used by the ICP, HTCP, and DNS
5904#	modules. Altering it will affect all of them in the same manner.
5905#
5906#	see also; udp_outgoing_address
5907#
5908#	NOTE, udp_incoming_address and udp_outgoing_address can not
5909#	have the same value since they both use the same port.
5910#Default:
5911# Accept packets from all machine interfaces.
5912
5913#  TAG: udp_outgoing_address
5914#	udp_outgoing_address	is used for UDP packets sent out to other
5915#				caches.
5916#
5917#	The default behavior is to not bind to any specific address.
5918#
5919#	Instead it will use the same socket as udp_incoming_address.
5920#	Only change this if you want to have UDP queries sent using another
5921#	address than where this Squid listens for UDP queries from other
5922#	caches.
5923#
5924#	NOTE: udp_outgoing_address is used by the ICP, HTCP, and DNS
5925#	modules. Altering it will affect all of them in the same manner.
5926#
5927#	see also; udp_incoming_address
5928#
5929#	NOTE, udp_incoming_address and udp_outgoing_address can not
5930#	have the same value since they both use the same port.
5931#Default:
5932# Use udp_incoming_address or an address selected by the operating system.
5933
5934#  TAG: icp_hit_stale	on|off
5935#	If you want to return ICP_HIT for stale cache objects, set this
5936#	option to 'on'.  If you have sibling relationships with caches
5937#	in other administrative domains, this should be 'off'.  If you only
5938#	have sibling relationships with caches under your control,
5939#	it is probably okay to set this to 'on'.
5940#	If set to 'on', your siblings should use the option "allow-miss"
5941#	on their cache_peer lines for connecting to you.
5942#Default:
5943# icp_hit_stale off
5944
5945#  TAG: minimum_direct_hops
5946#	If using the ICMP pinging stuff, do direct fetches for sites
5947#	which are no more than this many hops away.
5948#Default:
5949# minimum_direct_hops 4
5950
5951#  TAG: minimum_direct_rtt	(msec)
5952#	If using the ICMP pinging stuff, do direct fetches for sites
5953#	which are no more than this many rtt milliseconds away.
5954#Default:
5955# minimum_direct_rtt 400
5956
5957#  TAG: netdb_low
5958#	The low water mark for the ICMP measurement database.
5959#
5960#	Note: high watermark controlled by netdb_high directive.
5961#
5962#	These watermarks are counts, not percents.  The defaults are
5963#	(low) 900 and (high) 1000.  When the high water mark is
5964#	reached, database entries will be deleted until the low
5965#	mark is reached.
5966#Default:
5967# netdb_low 900
5968
5969#  TAG: netdb_high
5970#	The high water mark for the ICMP measurement database.
5971#
5972#	Note: low watermark controlled by netdb_low directive.
5973#
5974#	These watermarks are counts, not percents.  The defaults are
5975#	(low) 900 and (high) 1000.  When the high water mark is
5976#	reached, database entries will be deleted until the low
5977#	mark is reached.
5978#Default:
5979# netdb_high 1000
5980
5981#  TAG: netdb_ping_period
5982#	The minimum period for measuring a site.  There will be at
5983#	least this much delay between successive pings to the same
5984#	network.  The default is five minutes.
5985#Default:
5986# netdb_ping_period 5 minutes
5987
5988#  TAG: query_icmp	on|off
5989#	If you want to ask your peers to include ICMP data in their ICP
5990#	replies, enable this option.
5991#
5992#	If your peer has configured Squid (during compilation) with
5993#	'--enable-icmp' that peer will send ICMP pings to origin server
5994#	sites of the URLs it receives.  If you enable this option the
5995#	ICP replies from that peer will include the ICMP data (if available).
5996#	Then, when choosing a parent cache, Squid will choose the parent with
5997#	the minimal RTT to the origin server.  When this happens, the
5998#	hierarchy field of the access.log will be
5999#	"CLOSEST_PARENT_MISS".  This option is off by default.
6000#Default:
6001# query_icmp off
6002
6003#  TAG: test_reachability	on|off
6004#	When this is 'on', ICP MISS replies will be ICP_MISS_NOFETCH
6005#	instead of ICP_MISS if the target host is NOT in the ICMP
6006#	database, or has a zero RTT.
6007#Default:
6008# test_reachability off
6009
6010#  TAG: icp_query_timeout	(msec)
6011#	Normally Squid will automatically determine an optimal ICP
6012#	query timeout value based on the round-trip-time of recent ICP
6013#	queries.  If you want to override the value determined by
6014#	Squid, set this 'icp_query_timeout' to a non-zero value.  This
6015#	value is specified in MILLISECONDS, so, to use a 2-second
6016#	timeout (the old default), you would write:
6017#
6018#		icp_query_timeout 2000
6019#Default:
6020# Dynamic detection.
6021
6022#  TAG: maximum_icp_query_timeout	(msec)
6023#	Normally the ICP query timeout is determined dynamically.  But
6024#	sometimes it can lead to very large values (say 5 seconds).
6025#	Use this option to put an upper limit on the dynamic timeout
6026#	value.  Do NOT use this option to always use a fixed (instead
6027#	of a dynamic) timeout value. To set a fixed timeout see the
6028#	'icp_query_timeout' directive.
6029#Default:
6030# maximum_icp_query_timeout 2000
6031
6032#  TAG: minimum_icp_query_timeout	(msec)
6033#	Normally the ICP query timeout is determined dynamically.  But
6034#	sometimes it can lead to very small timeouts, even lower than
6035#	the normal latency variance on your link due to traffic.
6036#	Use this option to put an lower limit on the dynamic timeout
6037#	value.  Do NOT use this option to always use a fixed (instead
6038#	of a dynamic) timeout value. To set a fixed timeout see the
6039#	'icp_query_timeout' directive.
6040#Default:
6041# minimum_icp_query_timeout 5
6042
6043#  TAG: background_ping_rate	time-units
6044#	Controls how often the ICP pings are sent to siblings that
6045#	have background-ping set.
6046#Default:
6047# background_ping_rate 10 seconds
6048
6049# MULTICAST ICP OPTIONS
6050# -----------------------------------------------------------------------------
6051
6052#  TAG: mcast_groups
6053#	This tag specifies a list of multicast groups which your server
6054#	should join to receive multicasted ICP queries.
6055#
6056#	NOTE!  Be very careful what you put here!  Be sure you
6057#	understand the difference between an ICP _query_ and an ICP
6058#	_reply_.  This option is to be set only if you want to RECEIVE
6059#	multicast queries.  Do NOT set this option to SEND multicast
6060#	ICP (use cache_peer for that).  ICP replies are always sent via
6061#	unicast, so this option does not affect whether or not you will
6062#	receive replies from multicast group members.
6063#
6064#	You must be very careful to NOT use a multicast address which
6065#	is already in use by another group of caches.
6066#
6067#	If you are unsure about multicast, please read the Multicast
6068#	chapter in the Squid FAQ (http://www.squid-cache.org/FAQ/).
6069#
6070#	Usage: mcast_groups 239.128.16.128 224.0.1.20
6071#
6072#	By default, Squid doesn't listen on any multicast groups.
6073#Default:
6074# none
6075
6076#  TAG: mcast_miss_addr
6077# Note: This option is only available if Squid is rebuilt with the
6078#       -DMULTICAST_MISS_STREAM define
6079#
6080#	If you enable this option, every "cache miss" URL will
6081#	be sent out on the specified multicast address.
6082#
6083#	Do not enable this option unless you are are absolutely
6084#	certain you understand what you are doing.
6085#Default:
6086# disabled.
6087
6088#  TAG: mcast_miss_ttl
6089# Note: This option is only available if Squid is rebuilt with the
6090#       -DMULTICAST_MISS_STREAM define
6091#
6092#	This is the time-to-live value for packets multicasted
6093#	when multicasting off cache miss URLs is enabled.  By
6094#	default this is set to 'site scope', i.e. 16.
6095#Default:
6096# mcast_miss_ttl 16
6097
6098#  TAG: mcast_miss_port
6099# Note: This option is only available if Squid is rebuilt with the
6100#       -DMULTICAST_MISS_STREAM define
6101#
6102#	This is the port number to be used in conjunction with
6103#	'mcast_miss_addr'.
6104#Default:
6105# mcast_miss_port 3135
6106
6107#  TAG: mcast_miss_encode_key
6108# Note: This option is only available if Squid is rebuilt with the
6109#       -DMULTICAST_MISS_STREAM define
6110#
6111#	The URLs that are sent in the multicast miss stream are
6112#	encrypted.  This is the encryption key.
6113#Default:
6114# mcast_miss_encode_key XXXXXXXXXXXXXXXX
6115
6116#  TAG: mcast_icp_query_timeout	(msec)
6117#	For multicast peers, Squid regularly sends out ICP "probes" to
6118#	count how many other peers are listening on the given multicast
6119#	address.  This value specifies how long Squid should wait to
6120#	count all the replies.  The default is 2000 msec, or 2
6121#	seconds.
6122#Default:
6123# mcast_icp_query_timeout 2000
6124
6125# INTERNAL ICON OPTIONS
6126# -----------------------------------------------------------------------------
6127
6128#  TAG: icon_directory
6129#	Where the icons are stored. These are normally kept in
6130#	/usr/share/squid3/icons
6131#Default:
6132# icon_directory /usr/share/squid3/icons
6133
6134#  TAG: global_internal_static
6135#	This directive controls is Squid should intercept all requests for
6136#	/squid-internal-static/ no matter which host the URL is requesting
6137#	(default on setting), or if nothing special should be done for
6138#	such URLs (off setting). The purpose of this directive is to make
6139#	icons etc work better in complex cache hierarchies where it may
6140#	not always be possible for all corners in the cache mesh to reach
6141#	the server generating a directory listing.
6142#Default:
6143# global_internal_static on
6144
6145#  TAG: short_icon_urls
6146#	If this is enabled Squid will use short URLs for icons.
6147#	If disabled it will revert to the old behavior of including
6148#	it's own name and port in the URL.
6149#
6150#	If you run a complex cache hierarchy with a mix of Squid and
6151#	other proxies you may need to disable this directive.
6152#Default:
6153# short_icon_urls on
6154
6155# ERROR PAGE OPTIONS
6156# -----------------------------------------------------------------------------
6157
6158#  TAG: error_directory
6159#	If you wish to create your own versions of the default
6160#	error files to customize them to suit your company copy
6161#	the error/template files to another directory and point
6162#	this tag at them.
6163#
6164#	WARNING: This option will disable multi-language support
6165#	         on error pages if used.
6166#
6167#	The squid developers are interested in making squid available in
6168#	a wide variety of languages. If you are making translations for a
6169#	language that Squid does not currently provide please consider
6170#	contributing your translation back to the project.
6171#	http://wiki.squid-cache.org/Translations
6172#
6173#	The squid developers working on translations are happy to supply drop-in
6174#	translated error files in exchange for any new language contributions.
6175#Default:
6176# Send error pages in the clients preferred language
6177
6178#  TAG: error_default_language
6179#	Set the default language which squid will send error pages in
6180#	if no existing translation matches the clients language
6181#	preferences.
6182#
6183#	If unset (default) generic English will be used.
6184#
6185#	The squid developers are interested in making squid available in
6186#	a wide variety of languages. If you are interested in making
6187#	translations for any language see the squid wiki for details.
6188#	http://wiki.squid-cache.org/Translations
6189#Default:
6190# Generate English language pages.
6191
6192#  TAG: error_log_languages
6193#	Log to cache.log what languages users are attempting to
6194#	auto-negotiate for translations.
6195#
6196#	Successful negotiations are not logged. Only failures
6197#	have meaning to indicate that Squid may need an upgrade
6198#	of its error page translations.
6199#Default:
6200# error_log_languages on
6201
6202#  TAG: err_page_stylesheet
6203#	CSS Stylesheet to pattern the display of Squid default error pages.
6204#
6205#	For information on CSS see http://www.w3.org/Style/CSS/
6206#Default:
6207# err_page_stylesheet /etc/squid3/errorpage.css
6208
6209#  TAG: err_html_text
6210#	HTML text to include in error messages.  Make this a "mailto"
6211#	URL to your admin address, or maybe just a link to your
6212#	organizations Web page.
6213#
6214#	To include this in your error messages, you must rewrite
6215#	the error template files (found in the "errors" directory).
6216#	Wherever you want the 'err_html_text' line to appear,
6217#	insert a %L tag in the error template file.
6218#Default:
6219# none
6220
6221#  TAG: email_err_data	on|off
6222#	If enabled, information about the occurred error will be
6223#	included in the mailto links of the ERR pages (if %W is set)
6224#	so that the email body contains the data.
6225#	Syntax is <A HREF="mailto:%w%W">%w</A>
6226#Default:
6227# email_err_data on
6228
6229#  TAG: deny_info
6230#	Usage:   deny_info err_page_name acl
6231#	or       deny_info http://... acl
6232#	or       deny_info TCP_RESET acl
6233#
6234#	This can be used to return a ERR_ page for requests which
6235#	do not pass the 'http_access' rules.  Squid remembers the last
6236#	acl it evaluated in http_access, and if a 'deny_info' line exists
6237#	for that ACL Squid returns a corresponding error page.
6238#
6239#	The acl is typically the last acl on the http_access deny line which
6240#	denied access. The exceptions to this rule are:
6241#	- When Squid needs to request authentication credentials. It's then
6242#	  the first authentication related acl encountered
6243#	- When none of the http_access lines matches. It's then the last
6244#	  acl processed on the last http_access line.
6245#	- When the decision to deny access was made by an adaptation service,
6246#	  the acl name is the corresponding eCAP or ICAP service_name.
6247#
6248#	NP: If providing your own custom error pages with error_directory
6249#	    you may also specify them by your custom file name:
6250#	    Example: deny_info ERR_CUSTOM_ACCESS_DENIED bad_guys
6251#
6252#	By defaut Squid will send "403 Forbidden". A different 4xx or 5xx
6253#	may be specified by prefixing the file name with the code and a colon.
6254#	e.g. 404:ERR_CUSTOM_ACCESS_DENIED
6255#
6256#	Alternatively you can tell Squid to reset the TCP connection
6257#	by specifying TCP_RESET.
6258#
6259#	Or you can specify an error URL or URL pattern. The browsers will
6260#	get redirected to the specified URL after formatting tags have
6261#	been replaced. Redirect will be done with 302 or 307 according to
6262#	HTTP/1.1 specs. A different 3xx code may be specified by prefixing
6263#	the URL. e.g. 303:http://example.com/
6264#
6265#	URL FORMAT TAGS:
6266#		%a	- username (if available. Password NOT included)
6267#		%B	- FTP path URL
6268#		%e	- Error number
6269#		%E	- Error description
6270#		%h	- Squid hostname
6271#		%H	- Request domain name
6272#		%i	- Client IP Address
6273#		%M	- Request Method
6274#		%o	- Message result from external ACL helper
6275#		%p	- Request Port number
6276#		%P	- Request Protocol name
6277#		%R	- Request URL path
6278#		%T	- Timestamp in RFC 1123 format
6279#		%U	- Full canonical URL from client
6280#			  (HTTPS URLs terminate with *)
6281#		%u	- Full canonical URL from client
6282#		%w	- Admin email from squid.conf
6283#		%x	- Error name
6284#		%%	- Literal percent (%) code
6285#
6286#Default:
6287# none
6288
6289# OPTIONS INFLUENCING REQUEST FORWARDING 
6290# -----------------------------------------------------------------------------
6291
6292#  TAG: nonhierarchical_direct
6293#	By default, Squid will send any non-hierarchical requests
6294#	(matching hierarchy_stoplist or not cacheable request type) direct
6295#	to origin servers.
6296#
6297#	When this is set to "off", Squid will prefer to send these
6298#	requests to parents.
6299#
6300#	Note that in most configurations, by turning this off you will only
6301#	add latency to these request without any improvement in global hit
6302#	ratio.
6303#
6304#	This option only sets a preference. If the parent is unavailable a
6305#	direct connection to the origin server may still be attempted. To
6306#	completely prevent direct connections use never_direct.
6307#Default:
6308# nonhierarchical_direct on
6309
6310#  TAG: prefer_direct
6311#	Normally Squid tries to use parents for most requests. If you for some
6312#	reason like it to first try going direct and only use a parent if
6313#	going direct fails set this to on.
6314#
6315#	By combining nonhierarchical_direct off and prefer_direct on you
6316#	can set up Squid to use a parent as a backup path if going direct
6317#	fails.
6318#
6319#	Note: If you want Squid to use parents for all requests see
6320#	the never_direct directive. prefer_direct only modifies how Squid
6321#	acts on cacheable requests.
6322#Default:
6323# prefer_direct off
6324
6325#  TAG: cache_miss_revalidate	on|off
6326#	RFC 7232 defines a conditional request mechanism to prevent
6327#	response objects being unnecessarily transferred over the network.
6328#	If that mechanism is used by the client and a cache MISS occurs
6329#	it can prevent new cache entries being created.
6330#
6331#	This option determines whether Squid on cache MISS will pass the
6332#	client revalidation request to the server or tries to fetch new
6333#	content for caching. It can be useful while the cache is mostly
6334#	empty to more quickly have the cache populated by generating
6335#	non-conditional GETs.
6336#
6337#	When set to 'on' (default), Squid will pass all client If-* headers
6338#	to the server. This permits server responses without a cacheable
6339#	payload to be delivered and on MISS no new cache entry is created.
6340#
6341#	When set to 'off' and if the request is cacheable, Squid will
6342#	remove the clients If-Modified-Since and If-None-Match headers from
6343#	the request sent to the server. This requests a 200 status response
6344#	from the server to create a new cache entry with.
6345#Default:
6346# cache_miss_revalidate on
6347
6348#  TAG: always_direct
6349#	Usage: always_direct allow|deny [!]aclname ...
6350#
6351#	Here you can use ACL elements to specify requests which should
6352#	ALWAYS be forwarded by Squid to the origin servers without using
6353#	any peers.  For example, to always directly forward requests for
6354#	local servers ignoring any parents or siblings you may have use
6355#	something like:
6356#
6357#		acl local-servers dstdomain my.domain.net
6358#		always_direct allow local-servers
6359#
6360#	To always forward FTP requests directly, use
6361#
6362#		acl FTP proto FTP
6363#		always_direct allow FTP
6364#
6365#	NOTE: There is a similar, but opposite option named
6366#	'never_direct'.  You need to be aware that "always_direct deny
6367#	foo" is NOT the same thing as "never_direct allow foo".  You
6368#	may need to use a deny rule to exclude a more-specific case of
6369#	some other rule.  Example:
6370#
6371#		acl local-external dstdomain external.foo.net
6372#		acl local-servers dstdomain  .foo.net
6373#		always_direct deny local-external
6374#		always_direct allow local-servers
6375#
6376#	NOTE: If your goal is to make the client forward the request
6377#	directly to the origin server bypassing Squid then this needs
6378#	to be done in the client configuration. Squid configuration
6379#	can only tell Squid how Squid should fetch the object.
6380#
6381#	NOTE: This directive is not related to caching. The replies
6382#	is cached as usual even if you use always_direct. To not cache
6383#	the replies see the 'cache' directive.
6384#
6385#	This clause supports both fast and slow acl types.
6386#	See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
6387#Default:
6388# Prevent any cache_peer being used for this request.
6389
6390#  TAG: never_direct
6391#	Usage: never_direct allow|deny [!]aclname ...
6392#
6393#	never_direct is the opposite of always_direct.  Please read
6394#	the description for always_direct if you have not already.
6395#
6396#	With 'never_direct' you can use ACL elements to specify
6397#	requests which should NEVER be forwarded directly to origin
6398#	servers.  For example, to force the use of a proxy for all
6399#	requests, except those in your local domain use something like:
6400#
6401#		acl local-servers dstdomain .foo.net
6402#		never_direct deny local-servers
6403#		never_direct allow all
6404#
6405#	or if Squid is inside a firewall and there are local intranet
6406#	servers inside the firewall use something like:
6407#
6408#		acl local-intranet dstdomain .foo.net
6409#		acl local-external dstdomain external.foo.net
6410#		always_direct deny local-external
6411#		always_direct allow local-intranet
6412#		never_direct allow all
6413#
6414#	This clause supports both fast and slow acl types.
6415#	See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
6416#Default:
6417# Allow DNS results to be used for this request.
6418
6419# ADVANCED NETWORKING OPTIONS
6420# -----------------------------------------------------------------------------
6421
6422#  TAG: incoming_udp_average
6423#	Heavy voodoo here.  I can't even believe you are reading this.
6424#	Are you crazy?  Don't even think about adjusting these unless
6425#	you understand the algorithms in comm_select.c first!
6426#Default:
6427# incoming_udp_average 6
6428
6429#  TAG: incoming_tcp_average
6430#	Heavy voodoo here.  I can't even believe you are reading this.
6431#	Are you crazy?  Don't even think about adjusting these unless
6432#	you understand the algorithms in comm_select.c first!
6433#Default:
6434# incoming_tcp_average 4
6435
6436#  TAG: incoming_dns_average
6437#	Heavy voodoo here.  I can't even believe you are reading this.
6438#	Are you crazy?  Don't even think about adjusting these unless
6439#	you understand the algorithms in comm_select.c first!
6440#Default:
6441# incoming_dns_average 4
6442
6443#  TAG: min_udp_poll_cnt
6444#	Heavy voodoo here.  I can't even believe you are reading this.
6445#	Are you crazy?  Don't even think about adjusting these unless
6446#	you understand the algorithms in comm_select.c first!
6447#Default:
6448# min_udp_poll_cnt 8
6449
6450#  TAG: min_dns_poll_cnt
6451#	Heavy voodoo here.  I can't even believe you are reading this.
6452#	Are you crazy?  Don't even think about adjusting these unless
6453#	you understand the algorithms in comm_select.c first!
6454#Default:
6455# min_dns_poll_cnt 8
6456
6457#  TAG: min_tcp_poll_cnt
6458#	Heavy voodoo here.  I can't even believe you are reading this.
6459#	Are you crazy?  Don't even think about adjusting these unless
6460#	you understand the algorithms in comm_select.c first!
6461#Default:
6462# min_tcp_poll_cnt 8
6463
6464#  TAG: accept_filter
6465#	FreeBSD:
6466#
6467#	The name of an accept(2) filter to install on Squid's
6468#	listen socket(s).  This feature is perhaps specific to
6469#	FreeBSD and requires support in the kernel.
6470#
6471#	The 'httpready' filter delays delivering new connections
6472#	to Squid until a full HTTP request has been received.
6473#	See the accf_http(9) man page for details.
6474#
6475#	The 'dataready' filter delays delivering new connections
6476#	to Squid until there is some data to process.
6477#	See the accf_dataready(9) man page for details.
6478#
6479#	Linux:
6480#	
6481#	The 'data' filter delays delivering of new connections
6482#	to Squid until there is some data to process by TCP_ACCEPT_DEFER.
6483#	You may optionally specify a number of seconds to wait by
6484#	'data=N' where N is the number of seconds. Defaults to 30
6485#	if not specified.  See the tcp(7) man page for details.
6486#EXAMPLE:
6487## FreeBSD
6488#accept_filter httpready
6489## Linux
6490#accept_filter data
6491#Default:
6492# none
6493
6494#  TAG: client_ip_max_connections
6495#	Set an absolute limit on the number of connections a single
6496#	client IP can use. Any more than this and Squid will begin to drop
6497#	new connections from the client until it closes some links.
6498#
6499#	Note that this is a global limit. It affects all HTTP, HTCP, Gopher and FTP
6500#	connections from the client. For finer control use the ACL access controls.
6501#
6502#	Requires client_db to be enabled (the default).
6503#
6504#	WARNING: This may noticably slow down traffic received via external proxies
6505#	or NAT devices and cause them to rebound error messages back to their clients.
6506#Default:
6507# No limit.
6508
6509#  TAG: tcp_recv_bufsize	(bytes)
6510#	Size of receive buffer to set for TCP sockets.  Probably just
6511#	as easy to change your kernel's default.
6512#	Omit from squid.conf to use the default buffer size.
6513#Default:
6514# Use operating system TCP defaults.
6515
6516# ICAP OPTIONS
6517# -----------------------------------------------------------------------------
6518
6519#  TAG: icap_enable	on|off
6520#	If you want to enable the ICAP module support, set this to on.
6521#Default:
6522# icap_enable off
6523
6524#  TAG: icap_connect_timeout
6525#	This parameter specifies how long to wait for the TCP connect to
6526#	the requested ICAP server to complete before giving up and either
6527#	terminating the HTTP transaction or bypassing the failure.
6528#
6529#	The default for optional services is peer_connect_timeout.
6530#	The default for essential services is connect_timeout.
6531#	If this option is explicitly set, its value applies to all services.
6532#Default:
6533# none
6534
6535#  TAG: icap_io_timeout	time-units
6536#	This parameter specifies how long to wait for an I/O activity on
6537#	an established, active ICAP connection before giving up and
6538#	either terminating the HTTP transaction or bypassing the
6539#	failure.
6540#Default:
6541# Use read_timeout.
6542
6543#  TAG: icap_service_failure_limit	limit [in memory-depth time-units]
6544#	The limit specifies the number of failures that Squid tolerates
6545#	when establishing a new TCP connection with an ICAP service. If
6546#	the number of failures exceeds the limit, the ICAP service is
6547#	not used for new ICAP requests until it is time to refresh its
6548#	OPTIONS.
6549#
6550#	A negative value disables the limit. Without the limit, an ICAP
6551#	service will not be considered down due to connectivity failures
6552#	between ICAP OPTIONS requests.
6553#
6554#	Squid forgets ICAP service failures older than the specified
6555#	value of memory-depth. The memory fading algorithm 
6556#	is approximate because Squid does not remember individual 
6557#	errors but groups them instead, splitting the option
6558#	value into ten time slots of equal length.
6559#
6560#	When memory-depth is 0 and by default this option has no 
6561#	effect on service failure expiration.
6562#
6563#	Squid always forgets failures when updating service settings
6564#	using an ICAP OPTIONS transaction, regardless of this option
6565#	setting.
6566#
6567#	For example,
6568#		# suspend service usage after 10 failures in 5 seconds:
6569#		icap_service_failure_limit 10 in 5 seconds
6570#Default:
6571# icap_service_failure_limit 10
6572
6573#  TAG: icap_service_revival_delay
6574#	The delay specifies the number of seconds to wait after an ICAP
6575#	OPTIONS request failure before requesting the options again. The
6576#	failed ICAP service is considered "down" until fresh OPTIONS are
6577#	fetched.
6578#
6579#	The actual delay cannot be smaller than the hardcoded minimum
6580#	delay of 30 seconds.
6581#Default:
6582# icap_service_revival_delay 180
6583
6584#  TAG: icap_preview_enable	on|off
6585#	The ICAP Preview feature allows the ICAP server to handle the
6586#	HTTP message by looking only at the beginning of the message body
6587#	or even without receiving the body at all. In some environments, 
6588#	previews greatly speedup ICAP processing.
6589#
6590#	During an ICAP OPTIONS transaction, the server may tell	Squid what
6591#	HTTP messages should be previewed and how big the preview should be.
6592#	Squid will not use Preview if the server did not request one.
6593#
6594#	To disable ICAP Preview for all ICAP services, regardless of
6595#	individual ICAP server OPTIONS responses, set this option to "off".
6596#Example:
6597#icap_preview_enable off
6598#Default:
6599# icap_preview_enable on
6600
6601#  TAG: icap_preview_size
6602#	The default size of preview data to be sent to the ICAP server.
6603#	This value might be overwritten on a per server basis by OPTIONS requests.
6604#Default:
6605# No preview sent.
6606
6607#  TAG: icap_206_enable	on|off
6608#	206 (Partial Content) responses is an ICAP extension that allows the
6609#	ICAP agents to optionally combine adapted and original HTTP message
6610#	content. The decision to combine is postponed until the end of the
6611#	ICAP response. Squid supports Partial Content extension by default.
6612#
6613#	Activation of the Partial Content extension is negotiated with each
6614#	ICAP service during OPTIONS exchange. Most ICAP servers should handle
6615#	negotation correctly even if they do not support the extension, but
6616#	some might fail. To disable Partial Content support for all ICAP
6617#	services and to avoid any negotiation, set this option to "off".
6618#
6619#	Example:
6620#	    icap_206_enable off
6621#Default:
6622# icap_206_enable on
6623
6624#  TAG: icap_default_options_ttl
6625#	The default TTL value for ICAP OPTIONS responses that don't have
6626#	an Options-TTL header.
6627#Default:
6628# icap_default_options_ttl 60
6629
6630#  TAG: icap_persistent_connections	on|off
6631#	Whether or not Squid should use persistent connections to
6632#	an ICAP server.
6633#Default:
6634# icap_persistent_connections on
6635
6636#  TAG: adaptation_send_client_ip	on|off
6637#	If enabled, Squid shares HTTP client IP information with adaptation
6638#	services. For ICAP, Squid adds the X-Client-IP header to ICAP requests.
6639#	For eCAP, Squid sets the libecap::metaClientIp transaction option.
6640#
6641#	See also: adaptation_uses_indirect_client
6642#Default:
6643# adaptation_send_client_ip off
6644
6645#  TAG: adaptation_send_username	on|off
6646#	This sends authenticated HTTP client username (if available) to
6647#	the adaptation service.
6648#
6649#	For ICAP, the username value is encoded based on the
6650#	icap_client_username_encode option and is sent using the header
6651#	specified by the icap_client_username_header option.
6652#Default:
6653# adaptation_send_username off
6654
6655#  TAG: icap_client_username_header
6656#	ICAP request header name to use for adaptation_send_username.
6657#Default:
6658# icap_client_username_header X-Client-Username
6659
6660#  TAG: icap_client_username_encode	on|off
6661#	Whether to base64 encode the authenticated client username.
6662#Default:
6663# icap_client_username_encode off
6664
6665#  TAG: icap_service
6666#	Defines a single ICAP service using the following format:
6667#
6668#	icap_service id vectoring_point uri [option ...]
6669#
6670#	id: ID
6671#		an opaque identifier or name which is used to direct traffic to
6672#		this specific service. Must be unique among all adaptation
6673#		services in squid.conf.
6674#
6675#	vectoring_point: reqmod_precache|reqmod_postcache|respmod_precache|respmod_postcache
6676#		This specifies at which point of transaction processing the
6677#		ICAP service should be activated. *_postcache vectoring points
6678#		are not yet supported.
6679#
6680#	uri: icap://servername:port/servicepath
6681#		ICAP server and service location.
6682#
6683#	ICAP does not allow a single service to handle both REQMOD and RESPMOD
6684#	transactions. Squid does not enforce that requirement. You can specify
6685#	services with the same service_url and different vectoring_points. You
6686#	can even specify multiple identical services as long as their
6687#	service_names differ.
6688#
6689#	To activate a service, use the adaptation_access directive. To group
6690#	services, use adaptation_service_chain and adaptation_service_set.
6691#
6692#	Service options are separated by white space. ICAP services support
6693#	the following name=value options:
6694#
6695#	bypass=on|off|1|0
6696#		If set to 'on' or '1', the ICAP service is treated as
6697#		optional. If the service cannot be reached or malfunctions,
6698#		Squid will try to ignore any errors and process the message as
6699#		if the service was not enabled. No all ICAP errors can be
6700#		bypassed.  If set to 0, the ICAP service is treated as
6701#		essential and all ICAP errors will result in an error page
6702#		returned to the HTTP client.
6703#
6704#		Bypass is off by default: services are treated as essential.
6705#
6706#	routing=on|off|1|0
6707#		If set to 'on' or '1', the ICAP service is allowed to
6708#		dynamically change the current message adaptation plan by
6709#		returning a chain of services to be used next. The services
6710#		are specified using the X-Next-Services ICAP response header
6711#		value, formatted as a comma-separated list of service names.
6712#		Each named service should be configured in squid.conf. Other
6713#		services are ignored. An empty X-Next-Services value results
6714#		in an empty plan which ends the current adaptation.
6715#
6716#		Dynamic adaptation plan may cross or cover multiple supported
6717#		vectoring points in their natural processing order.
6718#
6719#		Routing is not allowed by default: the ICAP X-Next-Services
6720#		response header is ignored.
6721#
6722#	ipv6=on|off
6723#		Only has effect on split-stack systems. The default on those systems
6724#		is to use IPv4-only connections. When set to 'on' this option will
6725#		make Squid use IPv6-only connections to contact this ICAP service.
6726#
6727#	on-overload=block|bypass|wait|force
6728#		If the service Max-Connections limit has been reached, do
6729#		one of the following for each new ICAP transaction:
6730#		  * block:  send an HTTP error response to the client
6731#		  * bypass: ignore the "over-connected" ICAP service
6732#		  * wait:   wait (in a FIFO queue) for an ICAP connection slot
6733#		  * force:  proceed, ignoring the Max-Connections limit 
6734#
6735#		In SMP mode with N workers, each worker assumes the service
6736#		connection limit is Max-Connections/N, even though not all
6737#		workers may use a given service.
6738#
6739#		The default value is "bypass" if service is bypassable,
6740#		otherwise it is set to "wait".
6741#		
6742#
6743#	max-conn=number
6744#		Use the given number as the Max-Connections limit, regardless
6745#		of the Max-Connections value given by the service, if any.
6746#
6747#	Older icap_service format without optional named parameters is
6748#	deprecated but supported for backward compatibility.
6749#
6750#Example:
6751#icap_service svcBlocker reqmod_precache icap://icap1.mydomain.net:1344/reqmod bypass=0
6752#icap_service svcLogger reqmod_precache icap://icap2.mydomain.net:1344/respmod routing=on
6753#Default:
6754# none
6755
6756#  TAG: icap_class
6757#	This deprecated option was documented to define an ICAP service
6758#	chain, even though it actually defined a set of similar, redundant
6759#	services, and the chains were not supported. 
6760#
6761#	To define a set of redundant services, please use the
6762#	adaptation_service_set directive. For service chains, use
6763#	adaptation_service_chain.
6764#Default:
6765# none
6766
6767#  TAG: icap_access
6768#	This option is deprecated. Please use adaptation_access, which
6769#	has the same ICAP functionality, but comes with better
6770#	documentation, and eCAP support.
6771#Default:
6772# none
6773
6774# eCAP OPTIONS
6775# -----------------------------------------------------------------------------
6776
6777#  TAG: ecap_enable	on|off
6778#	Controls whether eCAP support is enabled.
6779#Default:
6780# ecap_enable off
6781
6782#  TAG: ecap_service
6783#	Defines a single eCAP service
6784#
6785#	ecap_service id vectoring_point uri [option ...]
6786#
6787#        id: ID
6788#		an opaque identifier or name which is used to direct traffic to
6789#		this specific service. Must be unique among all adaptation
6790#		services in squid.conf.
6791#
6792#	vectoring_point: reqmod_precache|reqmod_postcache|respmod_precache|respmod_postcache
6793#		This specifies at which point of transaction processing the
6794#		eCAP service should be activated. *_postcache vectoring points
6795#		are not yet supported.
6796#
6797#	uri: ecap://vendor/service_name?custom&cgi=style&parameters=optional
6798#		Squid uses the eCAP service URI to match this configuration
6799#		line with one of the dynamically loaded services. Each loaded
6800#		eCAP service must have a unique URI. Obtain the right URI from
6801#		the service provider.
6802#
6803#	To activate a service, use the adaptation_access directive. To group
6804#	services, use adaptation_service_chain and adaptation_service_set.
6805#
6806#	Service options are separated by white space. eCAP services support
6807#	the following name=value options:
6808#
6809#	bypass=on|off|1|0
6810#		If set to 'on' or '1', the eCAP service is treated as optional.
6811#		If the service cannot be reached or malfunctions, Squid will try
6812#		to ignore any errors and process the message as if the service
6813#		was not enabled. No all eCAP errors can be bypassed.
6814#		If set to 'off' or '0', the eCAP service is treated as essential
6815#		and all eCAP errors will result in an error page returned to the
6816#		HTTP client.
6817#
6818#                Bypass is off by default: services are treated as essential.
6819#
6820#	routing=on|off|1|0
6821#		If set to 'on' or '1', the eCAP service is allowed to
6822#		dynamically change the current message adaptation plan by
6823#		returning a chain of services to be used next.
6824#
6825#		Dynamic adaptation plan may cross or cover multiple supported
6826#		vectoring points in their natural processing order.
6827#
6828#		Routing is not allowed by default.
6829#
6830#	Older ecap_service format without optional named parameters is
6831#	deprecated but supported for backward compatibility.
6832#
6833#
6834#Example:
6835#ecap_service s1 reqmod_precache ecap://filters.R.us/leakDetector?on_error=block bypass=off
6836#ecap_service s2 respmod_precache ecap://filters.R.us/virusFilter config=/etc/vf.cfg bypass=on
6837#Default:
6838# none
6839
6840#  TAG: loadable_modules
6841#	Instructs Squid to load the specified dynamic module(s) or activate
6842#	preloaded module(s).
6843#Example:
6844#loadable_modules /usr/lib/MinimalAdapter.so
6845#Default:
6846# none
6847
6848# MESSAGE ADAPTATION OPTIONS
6849# -----------------------------------------------------------------------------
6850
6851#  TAG: adaptation_service_set
6852#
6853#	Configures an ordered set of similar, redundant services. This is
6854#	useful when hot standby or backup adaptation servers are available.
6855#
6856#	    adaptation_service_set set_name service_name1 service_name2 ...
6857#
6858# 	The named services are used in the set declaration order. The first
6859#	applicable adaptation service from the set is used first. The next
6860#	applicable service is tried if and only if the transaction with the
6861#	previous service fails and the message waiting to be adapted is still
6862#	intact.
6863#
6864#	When adaptation starts, broken services are ignored as if they were
6865#	not a part of the set. A broken service is a down optional service.
6866#
6867#	The services in a set must be attached to the same vectoring point
6868#	(e.g., pre-cache) and use the same adaptation method (e.g., REQMOD).
6869#
6870#	If all services in a set are optional then adaptation failures are
6871#	bypassable. If all services in the set are essential, then a
6872#	transaction failure with one service may still be retried using
6873#	another service from the set, but when all services fail, the master
6874#	transaction fails as well.
6875#
6876#	A set may contain a mix of optional and essential services, but that
6877#	is likely to lead to surprising results because broken services become
6878#	ignored (see above), making previously bypassable failures fatal.
6879#	Technically, it is the bypassability of the last failed service that
6880#	matters.
6881#
6882#	See also: adaptation_access adaptation_service_chain
6883#
6884#Example:
6885#adaptation_service_set svcBlocker urlFilterPrimary urlFilterBackup
6886#adaptation service_set svcLogger loggerLocal loggerRemote
6887#Default:
6888# none
6889
6890#  TAG: adaptation_service_chain
6891#
6892#	Configures a list of complementary services that will be applied
6893#	one-by-one, forming an adaptation chain or pipeline. This is useful
6894#	when Squid must perform different adaptations on the same message.
6895#
6896#	    adaptation_service_chain chain_name service_name1 svc_name2 ...
6897#
6898# 	The named services are used in the chain declaration order. The first
6899#	applicable adaptation service from the chain is used first. The next
6900#	applicable service is applied to the successful adaptation results of
6901#	the previous service in the chain.
6902#
6903#	When adaptation starts, broken services are ignored as if they were
6904#	not a part of the chain. A broken service is a down optional service.
6905#
6906#	Request satisfaction terminates the adaptation chain because Squid
6907#	does not currently allow declaration of RESPMOD services at the
6908#	"reqmod_precache" vectoring point (see icap_service or ecap_service).
6909#
6910#	The services in a chain must be attached to the same vectoring point
6911#	(e.g., pre-cache) and use the same adaptation method (e.g., REQMOD).
6912#
6913#	A chain may contain a mix of optional and essential services. If an
6914#	essential adaptation fails (or the failure cannot be bypassed for
6915#	other reasons), the master transaction fails. Otherwise, the failure
6916#	is bypassed as if the failed adaptation service was not in the chain.
6917#
6918#	See also: adaptation_access adaptation_service_set
6919#
6920#Example:
6921#adaptation_service_chain svcRequest requestLogger urlFilter leakDetector
6922#Default:
6923# none
6924
6925#  TAG: adaptation_access
6926#	Sends an HTTP transaction to an ICAP or eCAP adaptation	service.
6927#
6928#	adaptation_access service_name allow|deny [!]aclname...
6929#	adaptation_access set_name     allow|deny [!]aclname...
6930#
6931#	At each supported vectoring point, the adaptation_access
6932#	statements are processed in the order they appear in this
6933#	configuration file. Statements pointing to the following services
6934#	are ignored (i.e., skipped without checking their ACL):
6935#
6936#	    - services serving different vectoring points
6937#	    - "broken-but-bypassable" services
6938#	    - "up" services configured to ignore such transactions
6939#              (e.g., based on the ICAP Transfer-Ignore header).
6940#
6941#        When a set_name is used, all services in the set are checked
6942#	using the same rules, to find the first applicable one. See
6943#	adaptation_service_set for details.
6944#
6945#	If an access list is checked and there is a match, the
6946#	processing stops: For an "allow" rule, the corresponding
6947#	adaptation service is used for the transaction. For a "deny"
6948#	rule, no adaptation service is activated.
6949#
6950#	It is currently not possible to apply more than one adaptation
6951#	service at the same vectoring point to the same HTTP transaction.
6952#
6953#        See also: icap_service and ecap_service
6954#
6955#Example:
6956#adaptation_access service_1 allow all
6957#Default:
6958# Allow, unless rules exist in squid.conf.
6959
6960#  TAG: adaptation_service_iteration_limit
6961#	Limits the number of iterations allowed when applying adaptation
6962#	services to a message. If your longest adaptation set or chain
6963#	may have more than 16 services, increase the limit beyond its
6964#	default value of 16. If detecting infinite iteration loops sooner
6965#	is critical, make the iteration limit match the actual number
6966#	of services in your longest adaptation set or chain.
6967#
6968#	Infinite adaptation loops are most likely with routing services.
6969#
6970#	See also: icap_service routing=1
6971#Default:
6972# adaptation_service_iteration_limit 16
6973
6974#  TAG: adaptation_masterx_shared_names
6975#	For each master transaction (i.e., the HTTP request and response
6976#	sequence, including all related ICAP and eCAP exchanges), Squid
6977#	maintains a table of metadata. The table entries are (name, value)
6978#	pairs shared among eCAP and ICAP exchanges. The table is destroyed
6979#	with the master transaction.
6980#
6981#	This option specifies the table entry names that Squid must accept
6982#	from and forward to the adaptation transactions.
6983#
6984#	An ICAP REQMOD or RESPMOD transaction may set an entry in the 
6985#	shared table by returning an ICAP header field with a name 
6986#	specified in adaptation_masterx_shared_names.
6987#
6988#	An eCAP REQMOD or RESPMOD transaction may set an entry in the
6989#	shared table by implementing the libecap::visitEachOption() API
6990#	to provide an option with a name specified in
6991#	adaptation_masterx_shared_names.
6992#
6993#	Squid will store and forward the set entry to subsequent adaptation
6994#	transactions within the same master transaction scope.
6995#
6996#	Only one shared entry name is supported at this time.
6997#
6998#Example:
6999## share authentication information among ICAP services
7000#adaptation_masterx_shared_names X-Subscriber-ID
7001#Default:
7002# none
7003
7004#  TAG: adaptation_meta
7005#	This option allows Squid administrator to add custom ICAP request
7006#	headers or eCAP options to Squid ICAP requests or eCAP transactions.
7007#	Use it to pass custom authentication tokens and other
7008#	transaction-state related meta information to an ICAP/eCAP service.
7009#	
7010#	The addition of a meta header is ACL-driven:
7011#		adaptation_meta name value [!]aclname ...
7012#	
7013#	Processing for a given header name stops after the first ACL list match.
7014#	Thus, it is impossible to add two headers with the same name. If no ACL
7015#	lists match for a given header name, no such header is added. For 
7016#	example:
7017#	
7018#		# do not debug transactions except for those that need debugging
7019#		adaptation_meta X-Debug 1 needs_debugging
7020#	
7021#		# log all transactions except for those that must remain secret
7022#		adaptation_meta X-Log 1 !keep_secret
7023#	
7024#		# mark transactions from users in the "G 1" group
7025#		adaptation_meta X-Authenticated-Groups "G 1" authed_as_G1
7026#	
7027#	The "value" parameter may be a regular squid.conf token or a "double
7028#	quoted string". Within the quoted string, use backslash (\) to escape
7029#	any character, which is currently only useful for escaping backslashes
7030#	and double quotes. For example,
7031#	    "this string has one backslash (\\) and two \"quotes\""
7032#
7033#	Used adaptation_meta header values may be logged via %note
7034#	logformat code. If multiple adaptation_meta headers with the same name
7035#	are used during master transaction lifetime, the header values are
7036#	logged in the order they were used and duplicate values are ignored
7037#	(only the first repeated value will be logged).
7038#Default:
7039# none
7040
7041#  TAG: icap_retry
7042#	This ACL determines which retriable ICAP transactions are
7043#	retried. Transactions that received a complete ICAP response
7044#	and did not have to consume or produce HTTP bodies to receive
7045#	that response are usually retriable.
7046#
7047#	icap_retry allow|deny [!]aclname ...
7048#
7049#	Squid automatically retries some ICAP I/O timeouts and errors
7050#	due to persistent connection race conditions.
7051#
7052#	See also: icap_retry_limit
7053#Default:
7054# icap_retry deny all
7055
7056#  TAG: icap_retry_limit
7057#	Limits the number of retries allowed.
7058#
7059#	Communication errors due to persistent connection race
7060#	conditions are unavoidable, automatically retried, and do not
7061#	count against this limit.
7062#
7063#	See also: icap_retry
7064#Default:
7065# No retries are allowed.
7066
7067# DNS OPTIONS
7068# -----------------------------------------------------------------------------
7069
7070#  TAG: check_hostnames
7071#	For security and stability reasons Squid can check
7072#	hostnames for Internet standard RFC compliance. If you want
7073#	Squid to perform these checks turn this directive on.
7074#Default:
7075# check_hostnames off
7076
7077#  TAG: allow_underscore
7078#	Underscore characters is not strictly allowed in Internet hostnames
7079#	but nevertheless used by many sites. Set this to off if you want
7080#	Squid to be strict about the standard.
7081#	This check is performed only when check_hostnames is set to on.
7082#Default:
7083# allow_underscore on
7084
7085#  TAG: cache_dns_program
7086# Note: This option is only available if Squid is rebuilt with the
7087#       --disable-internal-dns
7088#
7089#	Specify the location of the executable for dnslookup process.
7090#Default:
7091# cache_dns_program /usr/lib/squid3/dnsserver
7092
7093#  TAG: dns_children
7094# Note: This option is only available if Squid is rebuilt with the
7095#       --disable-internal-dns
7096#
7097#	The maximum number of processes spawn to service DNS name lookups.
7098#	If you limit it too few Squid will have to wait for them to process
7099#	a backlog of requests, slowing it down. If you allow too many they
7100#	will use RAM and other system resources noticably.
7101#	The maximum this may be safely set to is 32.
7102#	
7103#	The startup= and idle= options allow some measure of skew in your
7104#	tuning.
7105#	
7106#		startup=
7107#	
7108#	Sets a minimum of how many processes are to be spawned when Squid
7109#	starts or reconfigures. When set to zero the first request will
7110#	cause spawning of the first child process to handle it.
7111#	
7112#	Starting too few will cause an initial slowdown in traffic as Squid
7113#	attempts to simultaneously spawn enough processes to cope.
7114#	
7115#		idle=
7116#	
7117#	Sets a minimum of how many processes Squid is to try and keep available
7118#	at all times. When traffic begins to rise above what the existing
7119#	processes can handle this many more will be spawned up to the maximum
7120#	configured. A minimum setting of 1 is required.
7121#Default:
7122# dns_children 32 startup=1 idle=1
7123
7124#  TAG: dns_retransmit_interval
7125#	Initial retransmit interval for DNS queries. The interval is
7126#	doubled each time all configured DNS servers have been tried.
7127#Default:
7128# dns_retransmit_interval 5 seconds
7129
7130#  TAG: dns_timeout
7131#	DNS Query timeout. If no response is received to a DNS query
7132#	within this time all DNS servers for the queried domain
7133#	are assumed to be unavailable.
7134#Default:
7135# dns_timeout 30 seconds
7136
7137#  TAG: dns_packet_max
7138#	Maximum number of bytes packet size to advertise via EDNS.
7139#	Set to "none" to disable EDNS large packet support.
7140#	
7141#	For legacy reasons DNS UDP replies will default to 512 bytes which
7142#	is too small for many responses. EDNS provides a means for Squid to
7143#	negotiate receiving larger responses back immediately without having
7144#	to failover with repeat requests. Responses larger than this limit
7145#	will retain the old behaviour of failover to TCP DNS.
7146#	
7147#	Squid has no real fixed limit internally, but allowing packet sizes
7148#	over 1500 bytes requires network jumbogram support and is usually not
7149#	necessary.
7150#	
7151#	WARNING: The RFC also indicates that some older resolvers will reply
7152#	with failure of the whole request if the extension is added. Some
7153#	resolvers have already been identified which will reply with mangled
7154#	EDNS response on occasion. Usually in response to many-KB jumbogram
7155#	sizes being advertised by Squid.
7156#	Squid will currently treat these both as an unable-to-resolve domain
7157#	even if it would be resolvable without EDNS.
7158#Default:
7159# EDNS disabled
7160
7161#  TAG: dns_defnames	on|off
7162#	Normally the RES_DEFNAMES resolver option is disabled
7163#	(see res_init(3)).  This prevents caches in a hierarchy
7164#	from interpreting single-component hostnames locally.  To allow
7165#	Squid to handle single-component names, enable this option.
7166#Default:
7167# Search for single-label domain names is disabled.
7168
7169#  TAG: dns_multicast_local	on|off
7170#	When set to on, Squid sends multicast DNS lookups on the local
7171#	network for domains ending in .local and .arpa.
7172#	This enables local servers and devices to be contacted in an
7173#	ad-hoc or zero-configuration network environment.
7174#Default:
7175# Search for .local and .arpa names is disabled.
7176
7177#  TAG: dns_nameservers
7178#	Use this if you want to specify a list of DNS name servers
7179#	(IP addresses) to use instead of those given in your
7180#	/etc/resolv.conf file.
7181#
7182#	On Windows platforms, if no value is specified here or in
7183#	the /etc/resolv.conf file, the list of DNS name servers are
7184#	taken from the Windows registry, both static and dynamic DHCP
7185#	configurations are supported.
7186#
7187#	Example: dns_nameservers 10.0.0.1 192.172.0.4
7188#Default:
7189# Use operating system definitions
7190
7191#  TAG: hosts_file
7192#	Location of the host-local IP name-address associations
7193#	database. Most Operating Systems have such a file on different
7194#	default locations:
7195#	- Un*X & Linux:    /etc/hosts
7196#	- Windows NT/2000: %SystemRoot%\system32\drivers\etc\hosts
7197#			   (%SystemRoot% value install default is c:\winnt)
7198#	- Windows XP/2003: %SystemRoot%\system32\drivers\etc\hosts
7199#			   (%SystemRoot% value install default is c:\windows)
7200#	- Windows 9x/Me:   %windir%\hosts
7201#			   (%windir% value is usually c:\windows)
7202#	- Cygwin:	   /etc/hosts
7203#
7204#	The file contains newline-separated definitions, in the
7205#	form ip_address_in_dotted_form name [name ...] names are
7206#	whitespace-separated. Lines beginning with an hash (#)
7207#	character are comments.
7208#
7209#	The file is checked at startup and upon configuration.
7210#	If set to 'none', it won't be checked.
7211#	If append_domain is used, that domain will be added to
7212#	domain-local (i.e. not containing any dot character) host
7213#	definitions.
7214#Default:
7215# hosts_file /etc/hosts
7216
7217#  TAG: append_domain
7218#	Appends local domain name to hostnames without any dots in
7219#	them.  append_domain must begin with a period.
7220#
7221#	Be warned there are now Internet names with no dots in
7222#	them using only top-domain names, so setting this may
7223#	cause some Internet sites to become unavailable.
7224#
7225#Example:
7226# append_domain .yourdomain.com
7227#Default:
7228# Use operating system definitions
7229
7230#  TAG: ignore_unknown_nameservers
7231#	By default Squid checks that DNS responses are received
7232#	from the same IP addresses they are sent to.  If they
7233#	don't match, Squid ignores the response and writes a warning
7234#	message to cache.log.  You can allow responses from unknown
7235#	nameservers by setting this option to 'off'.
7236#Default:
7237# ignore_unknown_nameservers on
7238
7239#  TAG: dns_v4_first
7240#	With the IPv6 Internet being as fast or faster than IPv4 Internet
7241#	for most networks Squid prefers to contact websites over IPv6.
7242#
7243#	This option reverses the order of preference to make Squid contact
7244#	dual-stack websites over IPv4 first. Squid will still perform both
7245#	IPv6 and IPv4 DNS lookups before connecting.
7246#
7247#	WARNING:
7248#	  This option will restrict the situations under which IPv6
7249#	  connectivity is used (and tested), potentially hiding network
7250#	  problems which would otherwise be detected and warned about.
7251#Default:
7252# dns_v4_first off
7253
7254#  TAG: ipcache_size	(number of entries)
7255#	Maximum number of DNS IP cache entries.
7256#Default:
7257# ipcache_size 1024
7258
7259#  TAG: ipcache_low	(percent)
7260#Default:
7261# ipcache_low 90
7262
7263#  TAG: ipcache_high	(percent)
7264#	The size, low-, and high-water marks for the IP cache.
7265#Default:
7266# ipcache_high 95
7267
7268#  TAG: fqdncache_size	(number of entries)
7269#	Maximum number of FQDN cache entries.
7270#Default:
7271# fqdncache_size 1024
7272
7273# MISCELLANEOUS
7274# -----------------------------------------------------------------------------
7275
7276#  TAG: configuration_includes_quoted_values	on|off
7277#	Previous Squid versions have defined "quoted/string" as syntax for
7278#	ACL to signifiy the value is an included file containing values and
7279#	has treated the " characters in other places of the configuration file
7280#	as part of the parameter value it was used for.
7281#
7282#	For compatibility with existing installations that behaviour
7283#	remains the default.
7284#
7285#	If this directive is set to 'on', Squid will start parsing each
7286#	"quoted string" as a single configuration directive parameter. The
7287#	quotes are stripped before the parameter value is interpreted or use.
7288#
7289#	That will continue for all lines until this directive is set to 'off',
7290#	where Squid will return to the default configuration parsing.
7291#
7292#	For example;
7293#
7294#		configuration_includes_quoted_values on
7295#		acl group external groupCheck Administrators "Internet Users" Guest
7296#		configuration_includes_quoted_values off
7297#
7298#Default:
7299# configuration_includes_quoted_values off
7300
7301#  TAG: memory_pools	on|off
7302#	If set, Squid will keep pools of allocated (but unused) memory
7303#	available for future use.  If memory is a premium on your
7304#	system and you believe your malloc library outperforms Squid
7305#	routines, disable this.
7306#Default:
7307# memory_pools on
7308
7309#  TAG: memory_pools_limit	(bytes)
7310#	Used only with memory_pools on:
7311#	memory_pools_limit 50 MB
7312#
7313#	If set to a non-zero value, Squid will keep at most the specified
7314#	limit of allocated (but unused) memory in memory pools. All free()
7315#	requests that exceed this limit will be handled by your malloc
7316#	library. Squid does not pre-allocate any memory, just safe-keeps
7317#	objects that otherwise would be free()d. Thus, it is safe to set
7318#	memory_pools_limit to a reasonably high value even if your
7319#	configuration will use less memory.
7320#
7321#	If set to none, Squid will keep all memory it can. That is, there
7322#	will be no limit on the total amount of memory used for safe-keeping.
7323#
7324#	To disable memory allocation optimization, do not set
7325#	memory_pools_limit to 0 or none. Set memory_pools to "off" instead.
7326#
7327#	An overhead for maintaining memory pools is not taken into account
7328#	when the limit is checked. This overhead is close to four bytes per
7329#	object kept. However, pools may actually _save_ memory because of
7330#	reduced memory thrashing in your malloc library.
7331#Default:
7332# memory_pools_limit 5 MB
7333
7334#  TAG: forwarded_for	on|off|transparent|truncate|delete
7335#	If set to "on", Squid will append your client's IP address
7336#	in the HTTP requests it forwards. By default it looks like:
7337#
7338#		X-Forwarded-For: 192.1.2.3
7339#
7340#	If set to "off", it will appear as
7341#
7342#		X-Forwarded-For: unknown
7343#
7344#	If set to "transparent", Squid will not alter the
7345#	X-Forwarded-For header in any way.
7346#
7347#	If set to "delete", Squid will delete the entire
7348#	X-Forwarded-For header.
7349#
7350#	If set to "truncate", Squid will remove all existing
7351#	X-Forwarded-For entries, and place the client IP as the sole entry.
7352#Default:
7353# forwarded_for on
7354
7355#  TAG: cachemgr_passwd
7356#	Specify passwords for cachemgr operations.
7357#
7358#	Usage: cachemgr_passwd password action action ...
7359#
7360#	Some valid actions are (see cache manager menu for a full list):
7361#		5min
7362#		60min
7363#		asndb
7364#		authenticator
7365#		cbdata
7366#		client_list
7367#		comm_incoming
7368#		config *
7369#		counters
7370#		delay
7371#		digest_stats
7372#		dns
7373#		events
7374#		filedescriptors
7375#		fqdncache
7376#		histograms
7377#		http_headers
7378#		info
7379#		io
7380#		ipcache
7381#		mem
7382#		menu
7383#		netdb
7384#		non_peers
7385#		objects
7386#		offline_toggle *
7387#		pconn
7388#		peer_select
7389#		reconfigure *
7390#		redirector
7391#		refresh
7392#		server_list
7393#		shutdown *
7394#		store_digest
7395#		storedir
7396#		utilization
7397#		via_headers
7398#		vm_objects
7399#
7400#	* Indicates actions which will not be performed without a
7401#	  valid password, others can be performed if not listed here.
7402#
7403#	To disable an action, set the password to "disable".
7404#	To allow performing an action without a password, set the
7405#	password to "none".
7406#
7407#	Use the keyword "all" to set the same password for all actions.
7408#
7409#Example:
7410# cachemgr_passwd secret shutdown
7411# cachemgr_passwd lesssssssecret info stats/objects
7412# cachemgr_passwd disable all
7413#Default:
7414# No password. Actions which require password are denied.
7415
7416#  TAG: client_db	on|off
7417#	If you want to disable collecting per-client statistics,
7418#	turn off client_db here.
7419#Default:
7420# client_db on
7421
7422#  TAG: refresh_all_ims	on|off
7423#	When you enable this option, squid will always check
7424#	the origin server for an update when a client sends an
7425#	If-Modified-Since request.  Many browsers use IMS
7426#	requests when the user requests a reload, and this
7427#	ensures those clients receive the latest version.
7428#
7429#	By default (off), squid may return a Not Modified response
7430#	based on the age of the cached version.
7431#Default:
7432# refresh_all_ims off
7433
7434#  TAG: reload_into_ims	on|off
7435#	When you enable this option, client no-cache or ``reload''
7436#	requests will be changed to If-Modified-Since requests.
7437#	Doing this VIOLATES the HTTP standard.  Enabling this
7438#	feature could make you liable for problems which it
7439#	causes.
7440#
7441#	see also refresh_pattern for a more selective approach.
7442#Default:
7443# reload_into_ims off
7444
7445#  TAG: connect_retries
7446#	This sets the maximum number of connection attempts made for each
7447#	TCP connection. The connect_retries attempts must all still
7448#	complete within the connection timeout period.
7449#
7450#	The default is not to re-try if the first connection attempt fails.
7451#	The (not recommended) maximum is 10 tries.
7452#
7453#	A warning message will be generated if it is set to a too-high
7454#	value and the configured value will be over-ridden.
7455#
7456#	Note: These re-tries are in addition to forward_max_tries
7457#	which limit how many different addresses may be tried to find
7458#	a useful server.
7459#Default:
7460# Do not retry failed connections.
7461
7462#  TAG: retry_on_error
7463#	If set to ON Squid will automatically retry requests when
7464#	receiving an error response with status 403 (Forbidden),
7465#	500 (Internal Error), 501 or 503 (Service not available).
7466#	Status 502 and 504 (Gateway errors) are always retried.
7467#	
7468#	This is mainly useful if you are in a complex cache hierarchy to
7469#	work around access control errors.
7470#	
7471#	NOTE: This retry will attempt to find another working destination.
7472#	Which is different from the server which just failed.
7473#Default:
7474# retry_on_error off
7475
7476#  TAG: as_whois_server
7477#	WHOIS server to query for AS numbers.  NOTE: AS numbers are
7478#	queried only when Squid starts up, not for every request.
7479#Default:
7480# as_whois_server whois.ra.net
7481
7482#  TAG: offline_mode
7483#	Enable this option and Squid will never try to validate cached
7484#	objects.
7485#Default:
7486# offline_mode off
7487
7488#  TAG: uri_whitespace
7489#	What to do with requests that have whitespace characters in the
7490#	URI.  Options:
7491#
7492#	strip:  The whitespace characters are stripped out of the URL.
7493#		This is the behavior recommended by RFC2396 and RFC3986
7494#		for tolerant handling of generic URI.
7495#		NOTE: This is one difference between generic URI and HTTP URLs.
7496#
7497#	deny:   The request is denied.  The user receives an "Invalid
7498#		Request" message.
7499#		This is the behaviour recommended by RFC2616 for safe
7500#		handling of HTTP request URL.
7501#
7502#	allow:  The request is allowed and the URI is not changed.  The
7503#		whitespace characters remain in the URI.  Note the
7504#		whitespace is passed to redirector processes if they
7505#		are in use.
7506#		Note this may be considered a violation of RFC2616
7507#		request parsing where whitespace is prohibited in the
7508#		URL field.
7509#
7510#	encode:	The request is allowed and the whitespace characters are
7511#		encoded according to RFC1738.
7512#
7513#	chop:	The request is allowed and the URI is chopped at the
7514#		first whitespace.
7515#
7516#
7517#	NOTE the current Squid implementation of encode and chop violates
7518#	RFC2616 by not using a 301 redirect after altering the URL.
7519#Default:
7520# uri_whitespace strip
7521
7522#  TAG: chroot
7523#	Specifies a directory where Squid should do a chroot() while
7524#	initializing.  This also causes Squid to fully drop root
7525#	privileges after initializing.  This means, for example, if you
7526#	use a HTTP port less than 1024 and try to reconfigure, you may
7527#	get an error saying that Squid can not open the port.
7528#Default:
7529# none
7530
7531#  TAG: balance_on_multiple_ip
7532#	Modern IP resolvers in squid sort lookup results by preferred access.
7533#	By default squid will use these IP in order and only rotates to
7534#	the next listed when the most preffered fails.
7535#
7536#	Some load balancing servers based on round robin DNS have been
7537#	found not to preserve user session state across requests
7538#	to different IP addresses.
7539#
7540#	Enabling this directive Squid rotates IP's per request.
7541#Default:
7542# balance_on_multiple_ip off
7543
7544#  TAG: pipeline_prefetch
7545#	HTTP clients may send a pipeline of 1+N requests to Squid using a
7546#	single connection, without waiting for Squid to respond to the first
7547#	of those requests. This option limits the number of concurrent
7548#	requests Squid will try to handle in parallel. If set to N, Squid
7549#	will try to receive and process up to 1+N requests on the same
7550#	connection concurrently.
7551#
7552#	Defaults to 0 (off) for bandwidth management and access logging
7553#	reasons.
7554#
7555#	NOTE: pipelining requires persistent connections to clients.
7556#
7557#	WARNING: pipelining breaks NTLM and Negotiate/Kerberos authentication.
7558#Default:
7559# Do not pre-parse pipelined requests.
7560
7561#  TAG: high_response_time_warning	(msec)
7562#	If the one-minute median response time exceeds this value,
7563#	Squid prints a WARNING with debug level 0 to get the
7564#	administrators attention.  The value is in milliseconds.
7565#Default:
7566# disabled.
7567
7568#  TAG: high_page_fault_warning
7569#	If the one-minute average page fault rate exceeds this
7570#	value, Squid prints a WARNING with debug level 0 to get
7571#	the administrators attention.  The value is in page faults
7572#	per second.
7573#Default:
7574# disabled.
7575
7576#  TAG: high_memory_warning
7577# Note: This option is only available if Squid is rebuilt with the
7578#       GNU Malloc with mstats()
7579#
7580#	If the memory usage (as determined by mallinfo) exceeds
7581#	this amount, Squid prints a WARNING with debug level 0 to get
7582#	the administrators attention.
7583#Default:
7584# disabled.
7585
7586#  TAG: sleep_after_fork	(microseconds)
7587#	When this is set to a non-zero value, the main Squid process
7588#	sleeps the specified number of microseconds after a fork()
7589#	system call. This sleep may help the situation where your
7590#	system reports fork() failures due to lack of (virtual)
7591#	memory. Note, however, if you have a lot of child
7592#	processes, these sleep delays will add up and your
7593#	Squid will not service requests for some amount of time
7594#	until all the child processes have been started.
7595#	On Windows value less then 1000 (1 milliseconds) are
7596#	rounded to 1000.
7597#Default:
7598# sleep_after_fork 0
7599
7600#  TAG: windows_ipaddrchangemonitor	on|off
7601# Note: This option is only available if Squid is rebuilt with the
7602#       MS Windows
7603#
7604#	On Windows Squid by default will monitor IP address changes and will 
7605#	reconfigure itself after any detected event. This is very useful for
7606#	proxies connected to internet with dial-up interfaces.
7607#	In some cases (a Proxy server acting as VPN gateway is one) it could be
7608#	desiderable to disable this behaviour setting this to 'off'.
7609#	Note: after changing this, Squid service must be restarted.
7610#Default:
7611# windows_ipaddrchangemonitor on
7612
7613#  TAG: eui_lookup
7614#	Whether to lookup the EUI or MAC address of a connected client.
7615#Default:
7616# eui_lookup on
7617
7618#  TAG: max_filedescriptors
7619#	Reduce the maximum number of filedescriptors supported below
7620#	the usual operating system defaults.
7621#
7622#	Remove from squid.conf to inherit the current ulimit setting.
7623#
7624#	Note: Changing this requires a restart of Squid. Also
7625#	not all I/O types supports large values (eg on Windows).
7626#Default:
7627# Use operating system limits set by ulimit.
7628
7629#  TAG: workers
7630#	Number of main Squid processes or "workers" to fork and maintain.
7631#	0: "no daemon" mode, like running "squid -N ..."
7632#	1: "no SMP" mode, start one main Squid process daemon (default)
7633#	N: start N main Squid process daemons (i.e., SMP mode)
7634#
7635#	In SMP mode, each worker does nearly all what a single Squid daemon
7636#	does (e.g., listen on http_port and forward HTTP requests).
7637#Default:
7638# SMP support disabled.
7639
7640#  TAG: cpu_affinity_map
7641#	Usage: cpu_affinity_map process_numbers=P1,P2,... cores=C1,C2,...
7642#
7643#	Sets 1:1 mapping between Squid processes and CPU cores. For example,
7644#
7645#	    cpu_affinity_map process_numbers=1,2,3,4 cores=1,3,5,7
7646#
7647#	affects processes 1 through 4 only and places them on the first
7648#	four even cores, starting with core #1.
7649#
7650#	CPU cores are numbered starting from 1. Requires support for
7651#	sched_getaffinity(2) and sched_setaffinity(2) system calls.
7652#
7653#	Multiple cpu_affinity_map options are merged.
7654#
7655#	See also: workers
7656#Default:
7657# Let operating system decide.