3 # $Id: cf.data.pre,v 1.502 2008/02/12 00:05:11 amosjeffries Exp $
5 # SQUID Web Proxy Cache http://www.squid-cache.org/
6 # ----------------------------------------------------------
8 # Squid is the result of efforts by numerous individuals from
9 # the Internet community; see the CONTRIBUTORS file for full
10 # details. Many organizations have provided support for Squid's
11 # development; see the SPONSORS file for full details. Squid is
12 # Copyrighted (C) 2000 by the Regents of the University of
13 # California; see the COPYRIGHT file for full details. Squid
14 # incorporates software developed and/or copyrighted by other
15 # sources; see the CREDITS file for full details.
17 # This program is free software; you can redistribute it and/or modify
18 # it under the terms of the GNU General Public License as published by
19 # the Free Software Foundation; either version 2 of the License, or
20 # (at your option) any later version.
22 # This program is distributed in the hope that it will be useful,
23 # but WITHOUT ANY WARRANTY; without even the implied warranty of
24 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
25 # GNU General Public License for more details.
27 # You should have received a copy of the GNU General Public License
28 # along with this program; if not, write to the Free Software
29 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
33 WELCOME TO SQUID @VERSION@
34 ----------------------------
36 This is the default Squid configuration file. You may wish
37 to look at the Squid home page (http://www.squid-cache.org/)
38 for the FAQ and other documentation.
40 The default Squid config file shows what the defaults for
41 various options happen to be. If you don't need to change the
42 default, you shouldn't uncomment the line. Doing so may cause
43 run-time problems. In some cases "none" refers to no default
44 setting at all, while in other cases it refers to a valid
45 option - the comments for that keyword indicate if this is the
51 Configuration options can be included using the "include" directive.
52 Include takes a list of files to include. Quoting and wildcards is
57 include /path/to/included/file/squid.acl.config
59 Includes can be nested up to a hard-coded depth of 16 levels.
60 This arbitrary restriction is to prevent recursive include references
61 from causing Squid entering an infinite loop whilst trying to load
66 OPTIONS FOR AUTHENTICATION
67 -----------------------------------------------------------------------------
72 LOC: Config.authConfiguration
75 This is used to define parameters for the various authentication
76 schemes supported by Squid.
78 format: auth_param scheme parameter [setting]
80 The order in which authentication schemes are presented to the client is
81 dependent on the order the scheme first appears in config file. IE
82 has a bug (it's not RFC 2617 compliant) in that it will use the basic
83 scheme if basic is the first entry presented, even if more secure
84 schemes are presented. For now use the order in the recommended
85 settings section below. If other browsers have difficulties (don't
86 recognize the schemes offered even if you are using basic) either
87 put basic first, or disable the other schemes (by commenting out their
90 Once an authentication scheme is fully configured, it can only be
91 shutdown by shutting squid down and restarting. Changes can be made on
92 the fly and activated with a reconfigure. I.E. You can change to a
93 different helper, but not unconfigure the helper completely.
95 Please note that while this directive defines how Squid processes
96 authentication it does not automatically activate authentication.
97 To use authentication you must in addition make use of ACLs based
98 on login name in http_access (proxy_auth, proxy_auth_regex or
99 external with %LOGIN used in the format tag). The browser will be
100 challenged for authentication on the first such acl encountered
101 in http_access processing and will also be re-challenged for new
102 login credentials if the request is being denied by a proxy_auth
105 WARNING: authentication can't be used in a transparently intercepting
106 proxy as the client then thinks it is talking to an origin server and
107 not the proxy. This is a limitation of bending the TCP/IP protocol to
108 transparently intercepting port 80, not a limitation in Squid.
109 Ports flagged 'transparent', 'intercept', or 'tproxy' have authentication
112 === Parameters for the basic scheme follow. ===
115 Specify the command for the external authenticator. Such a program
116 reads a line containing "username password" and replies "OK" or
117 "ERR" in an endless loop. "ERR" responses may optionally be followed
118 by a error description available as %m in the returned error page.
119 If you use an authenticator, make sure you have 1 acl of type proxy_auth.
121 By default, the basic authentication scheme is not used unless a
122 program is specified.
124 If you want to use the traditional NCSA proxy authentication, set
125 this line to something like
127 auth_param basic program @DEFAULT_PREFIX@/libexec/ncsa_auth @DEFAULT_PREFIX@/etc/passwd
129 "children" numberofchildren
130 The number of authenticator processes to spawn. If you start too few
131 Squid will have to wait for them to process a backlog of credential
132 verifications, slowing it down. When password verifications are
133 done via a (slow) network you are likely to need lots of
134 authenticator processes.
135 auth_param basic children 5
137 "concurrency" concurrency
138 The number of concurrent requests the helper can process.
139 The default of 0 is used for helpers who only supports
140 one request at a time. Setting this changes the protocol used to
141 include a channel number first on the request/response line, allowing
142 multiple requests to be sent to the same helper in parallell without
143 wating for the response.
144 Must not be set unless it's known the helper supports this.
145 auth_param basic concurrency 0
148 Specifies the realm name which is to be reported to the
149 client for the basic proxy authentication scheme (part of
150 the text the user will see when prompted their username and
151 password). There is no default.
152 auth_param basic realm Squid proxy-caching web server
154 "credentialsttl" timetolive
155 Specifies how long squid assumes an externally validated
156 username:password pair is valid for - in other words how
157 often the helper program is called for that user. Set this
158 low to force revalidation with short lived passwords. Note
159 setting this high does not impact your susceptibility
160 to replay attacks unless you are using an one-time password
161 system (such as SecureID). If you are using such a system,
162 you will be vulnerable to replay attacks unless you also
163 use the max_user_ip ACL in an http_access rule.
165 "casesensitive" on|off
166 Specifies if usernames are case sensitive. Most user databases are
167 case insensitive allowing the same username to be spelled using both
168 lower and upper case letters, but some are case sensitive. This
169 makes a big difference for user_max_ip ACL processing and similar.
170 auth_param basic casesensitive off
172 === Parameters for the digest scheme follow ===
175 Specify the command for the external authenticator. Such
176 a program reads a line containing "username":"realm" and
177 replies with the appropriate H(A1) value hex encoded or
178 ERR if the user (or his H(A1) hash) does not exists.
179 See rfc 2616 for the definition of H(A1).
180 "ERR" responses may optionally be followed by a error description
181 available as %m in the returned error page.
183 By default, the digest authentication scheme is not used unless a
184 program is specified.
186 If you want to use a digest authenticator, set this line to
189 auth_param digest program @DEFAULT_PREFIX@/bin/digest_auth_pw @DEFAULT_PREFIX@/etc/digpass
191 "children" numberofchildren
192 The number of authenticator processes to spawn (no default).
193 If you start too few Squid will have to wait for them to
194 process a backlog of H(A1) calculations, slowing it down.
195 When the H(A1) calculations are done via a (slow) network
196 you are likely to need lots of authenticator processes.
197 auth_param digest children 5
200 Specifies the realm name which is to be reported to the
201 client for the digest proxy authentication scheme (part of
202 the text the user will see when prompted their username and
203 password). There is no default.
204 auth_param digest realm Squid proxy-caching web server
206 "nonce_garbage_interval" timeinterval
207 Specifies the interval that nonces that have been issued
208 to client_agent's are checked for validity.
210 "nonce_max_duration" timeinterval
211 Specifies the maximum length of time a given nonce will be
214 "nonce_max_count" number
215 Specifies the maximum number of times a given nonce can be
218 "nonce_strictness" on|off
219 Determines if squid requires strict increment-by-1 behavior
220 for nonce counts, or just incrementing (off - for use when
221 useragents generate nonce counts that occasionally miss 1
222 (ie, 1,2,4,6)). Default off.
224 "check_nonce_count" on|off
225 This directive if set to off can disable the nonce count check
226 completely to work around buggy digest qop implementations in
227 certain mainstream browser versions. Default on to check the
228 nonce count to protect from authentication replay attacks.
230 "post_workaround" on|off
231 This is a workaround to certain buggy browsers who sends
232 an incorrect request digest in POST requests when reusing
233 the same nonce as acquired earlier on a GET request.
235 === NTLM scheme options follow ===
238 Specify the command for the external NTLM authenticator.
239 Such a program reads exchanged NTLMSSP packets with
240 the browser via Squid until authentication is completed.
241 If you use an NTLM authenticator, make sure you have 1 acl
242 of type proxy_auth. By default, the NTLM authenticator_program
245 auth_param ntlm program @DEFAULT_PREFIX@/bin/ntlm_auth
247 "children" numberofchildren
248 The number of authenticator processes to spawn (no default).
249 If you start too few Squid will have to wait for them to
250 process a backlog of credential verifications, slowing it
251 down. When credential verifications are done via a (slow)
252 network you are likely to need lots of authenticator
255 auth_param ntlm children 5
258 If you experience problems with PUT/POST requests when using the
259 Negotiate authentication scheme then you can try setting this to
260 off. This will cause Squid to forcibly close the connection on
261 the initial requests where the browser asks which schemes are
262 supported by the proxy.
264 auth_param ntlm keep_alive on
266 === Options for configuring the NEGOTIATE auth-scheme follow ===
269 Specify the command for the external Negotiate authenticator.
270 This protocol is used in Microsoft Active-Directory enabled setups with
271 the Microsoft Internet Explorer or Mozilla Firefox browsers.
272 Its main purpose is to exchange credentials with the Squid proxy
273 using the Kerberos mechanisms.
274 If you use a Negotiate authenticator, make sure you have at least one acl
275 of type proxy_auth active. By default, the negotiate authenticator_program
277 The only supported program for this role is the ntlm_auth
278 program distributed as part of Samba, version 4 or later.
280 auth_param negotiate program @DEFAULT_PREFIX@/bin/ntlm_auth --helper-protocol=gss-spnego
282 "children" numberofchildren
283 The number of authenticator processes to spawn (no default).
284 If you start too few Squid will have to wait for them to
285 process a backlog of credential verifications, slowing it
286 down. When crendential verifications are done via a (slow)
287 network you are likely to need lots of authenticator
289 auth_param negotiate children 5
292 If you experience problems with PUT/POST requests when using the
293 Negotiate authentication scheme then you can try setting this to
294 off. This will cause Squid to forcibly close the connection on
295 the initial requests where the browser asks which schemes are
296 supported by the proxy.
298 auth_param negotiate keep_alive on
301 #Recommended minimum configuration per scheme:
302 #auth_param negotiate program <uncomment and complete this line to activate>
303 #auth_param negotiate children 5
304 #auth_param negotiate keep_alive on
305 #auth_param ntlm program <uncomment and complete this line to activate>
306 #auth_param ntlm children 5
307 #auth_param ntlm keep_alive on
308 #auth_param digest program <uncomment and complete this line>
309 #auth_param digest children 5
310 #auth_param digest realm Squid proxy-caching web server
311 #auth_param digest nonce_garbage_interval 5 minutes
312 #auth_param digest nonce_max_duration 30 minutes
313 #auth_param digest nonce_max_count 50
314 #auth_param basic program <uncomment and complete this line>
315 #auth_param basic children 5
316 #auth_param basic realm Squid proxy-caching web server
317 #auth_param basic credentialsttl 2 hours
321 NAME: authenticate_cache_garbage_interval
324 LOC: Config.authenticateGCInterval
326 The time period between garbage collection across the username cache.
327 This is a tradeoff between memory utilization (long intervals - say
328 2 days) and CPU (short intervals - say 1 minute). Only change if you
332 NAME: authenticate_ttl
335 LOC: Config.authenticateTTL
337 The time a user & their credentials stay in the logged in
338 user cache since their last request. When the garbage
339 interval passes, all user credentials that have passed their
340 TTL are removed from memory.
343 NAME: authenticate_ip_ttl
345 LOC: Config.authenticateIpTTL
348 If you use proxy authentication and the 'max_user_ip' ACL,
349 this directive controls how long Squid remembers the IP
350 addresses associated with each user. Use a small value
351 (e.g., 60 seconds) if your users might change addresses
352 quickly, as is the case with dialups. You might be safe
353 using a larger value (e.g., 2 hours) in a corporate LAN
354 environment with relatively static address assignments.
359 -----------------------------------------------------------------------------
362 NAME: external_acl_type
363 TYPE: externalAclHelper
364 LOC: Config.externalAclHelperList
367 This option defines external acl classes using a helper program
368 to look up the status
370 external_acl_type name [options] FORMAT.. /path/to/helper [helper arguments..]
374 ttl=n TTL in seconds for cached results (defaults to 3600
377 TTL for cached negative lookups (default same
379 children=n Number of acl helper processes spawn to service
380 external acl lookups of this type. (default 5)
381 concurrency=n concurrency level per process. Only used with helpers
382 capable of processing more than one query at a time.
383 cache=n result cache size, 0 is unbounded (default)
384 grace=n Percentage remaining of TTL where a refresh of a
385 cached entry should be initiated without needing to
386 wait for a new reply. (default 0 for no grace period)
387 protocol=2.5 Compatibility mode for Squid-2.5 external acl helpers
388 ipv4 / ipv6 IP-mode used to communicate to this helper.
389 For compatability with older configurations and helpers
390 'ipv4' is the default unless --with-localhost-ipv6 is used.
391 --with-localhost-ipv6 changes the default to 'ipv6'.
392 SPECIAL NOTE: these options override --with-localhost-ipv6
394 FORMAT specifications
396 %LOGIN Authenticated user login name
397 %EXT_USER Username from external acl
398 %IDENT Ident user name
400 %SRCPORT Client source port
403 %PROTO Requested protocol
405 %PATH Requested URL path
406 %METHOD Request method
407 %MYADDR Squid interface address
408 %MYPORT Squid http_port number
409 %PATH Requested URL-path (including query-string if any)
410 %USER_CERT SSL User certificate in PEM format
411 %USER_CERTCHAIN SSL User certificate chain in PEM format
412 %USER_CERT_xx SSL User certificate subject attribute xx
413 %USER_CA_xx SSL User certificate issuer attribute xx
414 %{Header} HTTP request header
415 %{Hdr:member} HTTP request header list member
417 HTTP request header list member using ; as
418 list separator. ; can be any non-alphanumeric
421 In addition to the above, any string specified in the referencing
422 acl will also be included in the helper request line, after the
423 specified formats (see the "acl external" directive)
425 The helper receives lines per the above format specification,
426 and returns lines starting with OK or ERR indicating the validity
427 of the request and optionally followed by additional keywords with
430 General result syntax:
432 OK/ERR keyword=value ...
436 user= The users name (login)
437 password= The users password (for login= cache_peer option)
438 message= Message describing the reason. Available as %o
440 tag= Apply a tag to a request (for both ERR and OK results)
441 Only sets a tag, does not alter existing tags.
442 log= String to be logged in access.log. Available as
443 %ea in logformat specifications
445 If protocol=3.0 (the default) then URL escaping is used to protect
446 each value in both requests and responses.
448 If using protocol=2.5 then all values need to be enclosed in quotes
449 if they may contain whitespace, or the whitespace escaped using \.
450 And quotes or \ characters within the keyword value must be \ escaped.
452 When using the concurrency= option the protocol is changed by
453 introducing a query channel tag infront of the request/response.
454 The query channel tag is a number between 0 and concurrency-1.
462 Defining an Access List
464 acl aclname acltype string1 ...
465 acl aclname acltype "file" ...
467 when using "file", the file should contain one item per line
469 acltype is one of the types described below
471 By default, regular expressions are CASE-SENSITIVE. To make
472 them case-insensitive, use the -i option.
475 ***** ACL TYPES AVAILABLE *****
477 acl aclname src ip-address/netmask ... (clients IP address)
478 acl aclname src addr1-addr2/netmask ... (range of addresses)
479 acl aclname dst ip-address/netmask ... (URL host's IP address)
480 acl aclname myip ip-address/netmask ... (local socket IP address)
482 acl aclname arp mac-address ... (xx:xx:xx:xx:xx:xx notation)
483 # The arp ACL requires the special configure option --enable-arp-acl.
484 # Furthermore, the ARP ACL code is not portable to all operating systems.
485 # It works on Linux, Solaris, Windows, FreeBSD, and some other *BSD variants.
487 # NOTE: Squid can only determine the MAC address for clients that are on
488 # the same subnet. If the client is on a different subnet, then Squid cannot
489 # find out its MAC address.
491 acl aclname srcdomain .foo.com ... # reverse lookup, from client IP
492 acl aclname dstdomain .foo.com ... # Destination server from URL
493 acl aclname srcdom_regex [-i] xxx ... # regex matching client name
494 acl aclname dstdom_regex [-i] xxx ... # regex matching server
495 # For dstdomain and dstdom_regex a reverse lookup is tried if a IP
496 # based URL is used and no match is found. The name "none" is used
497 # if the reverse lookup fails.
499 acl aclname src_as number ...
500 acl aclname dst_as number ...
501 # Except for access control, AS numbers can be used for
502 # routing of requests to specific caches. Here's an
503 # example for routing all requests for AS#1241 and only
504 # those to mycache.mydomain.net:
505 # acl asexample dst_as 1241
506 # cache_peer_access mycache.mydomain.net allow asexample
507 # cache_peer_access mycache_mydomain.net deny all
509 acl aclname time [day-abbrevs] [h1:m1-h2:m2]
518 h1:m1 must be less than h2:m2
520 acl aclname url_regex [-i] ^http:// ... # regex matching on whole URL
521 acl aclname urlpath_regex [-i] \.gif$ ... # regex matching on URL path
523 acl aclname port 80 70 21 ...
524 acl aclname port 0-1024 ... # ranges allowed
525 acl aclname myport 3128 ... # (local socket TCP port)
526 acl aclname myportname 3128 ... # http(s)_port name
528 acl aclname proto HTTP FTP ...
530 acl aclname method GET POST ...
532 acl aclname http_status 200 301 500- 400-403 ... # status code in reply
534 acl aclname browser [-i] regexp ...
535 # pattern match on User-Agent header (see also req_header below)
537 acl aclname referer_regex [-i] regexp ...
538 # pattern match on Referer header
539 # Referer is highly unreliable, so use with care
541 acl aclname ident username ...
542 acl aclname ident_regex [-i] pattern ...
543 # string match on ident output.
544 # use REQUIRED to accept any non-null ident.
546 acl aclname proxy_auth [-i] username ...
547 acl aclname proxy_auth_regex [-i] pattern ...
548 # list of valid usernames
549 # use REQUIRED to accept any valid username.
551 # NOTE: when a Proxy-Authentication header is sent but it is not
552 # needed during ACL checking the username is NOT logged
555 # NOTE: proxy_auth requires a EXTERNAL authentication program
556 # to check username/password combinations (see
557 # auth_param directive).
559 # NOTE: proxy_auth can't be used in a transparent/intercepting proxy
560 # as the browser needs to be configured for using a proxy in order
561 # to respond to proxy authentication.
563 acl aclname snmp_community string ...
564 # A community string to limit access to your SNMP Agent
567 # acl snmppublic snmp_community public
569 acl aclname maxconn number
570 # This will be matched when the client's IP address has
571 # more than <number> HTTP connections established.
573 acl aclname max_user_ip [-s] number
574 # This will be matched when the user attempts to log in from more
575 # than <number> different ip addresses. The authenticate_ip_ttl
576 # parameter controls the timeout on the ip entries.
577 # If -s is specified the limit is strict, denying browsing
578 # from any further IP addresses until the ttl has expired. Without
579 # -s Squid will just annoy the user by "randomly" denying requests.
580 # (the counter is reset each time the limit is reached and a
582 # NOTE: in acceleration mode or where there is mesh of child proxies,
583 # clients may appear to come from multiple addresses if they are
584 # going through proxy farms, so a limit of 1 may cause user problems.
586 acl aclname req_mime_type [-i] mime-type1 ...
587 # regex match against the mime type of the request generated
588 # by the client. Can be used to detect file upload or some
589 # types HTTP tunneling requests.
590 # NOTE: This does NOT match the reply. You cannot use this
591 # to match the returned file type.
593 acl aclname req_header header-name [-i] any\.regex\.here
594 # regex match against any of the known request headers. May be
595 # thought of as a superset of "browser", "referer" and "mime-type"
598 acl aclname rep_mime_type [-i] mime-type1 ...
599 # regex match against the mime type of the reply received by
600 # squid. Can be used to detect file download or some
601 # types HTTP tunneling requests.
602 # NOTE: This has no effect in http_access rules. It only has
603 # effect in rules that affect the reply data stream such as
606 acl aclname rep_header header-name [-i] any\.regex\.here
607 # regex match against any of the known reply headers. May be
608 # thought of as a superset of "browser", "referer" and "mime-type"
611 acl acl_name external class_name [arguments...]
612 # external ACL lookup via a helper class defined by the
613 # external_acl_type directive.
615 acl aclname user_cert attribute values...
616 # match against attributes in a user SSL certificate
617 # attribute is one of DN/C/O/CN/L/ST
619 acl aclname ca_cert attribute values...
620 # match against attributes a users issuing CA SSL certificate
621 # attribute is one of DN/C/O/CN/L/ST
623 acl aclname ext_user username ...
624 acl aclname ext_user_regex [-i] pattern ...
625 # string match on username returned by external acl helper
626 # use REQUIRED to accept any non-null user name.
629 acl macaddress arp 09:00:2b:23:45:67
630 acl myexample dst_as 1241
631 acl password proxy_auth REQUIRED
632 acl fileupload req_mime_type -i ^multipart/form-data$
633 acl javascript rep_mime_type -i ^application/x-javascript$
636 #Recommended minimum configuration:
637 acl manager proto cache_object
638 acl localhost src 127.0.0.1/32
639 acl to_localhost dst 127.0.0.0/8
641 # Example rule allowing access from your local networks.
642 # Adapt to list your (internal) IP networks from where browsing
644 acl localnet src 10.0.0.0/8 # RFC1918 possible internal network
645 acl localnet src 172.16.0.0/12 # RFC1918 possible internal network
646 acl localnet src 192.168.0.0/16 # RFC1918 possible internal network
648 acl SSL_ports port 443
649 acl Safe_ports port 80 # http
650 acl Safe_ports port 21 # ftp
651 acl Safe_ports port 443 # https
652 acl Safe_ports port 70 # gopher
653 acl Safe_ports port 210 # wais
654 acl Safe_ports port 1025-65535 # unregistered ports
655 acl Safe_ports port 280 # http-mgmt
656 acl Safe_ports port 488 # gss-http
657 acl Safe_ports port 591 # filemaker
658 acl Safe_ports port 777 # multiling http
659 acl CONNECT method CONNECT
663 NAME: follow_x_forwarded_for
665 IFDEF: FOLLOW_X_FORWARDED_FOR
666 LOC: Config.accessList.followXFF
668 DEFAULT_IF_NONE: deny all
670 Allowing or Denying the X-Forwarded-For header to be followed to
671 find the original source of a request.
673 Requests may pass through a chain of several other proxies
674 before reaching us. The X-Forwarded-For header will contain a
675 comma-separated list of the IP addresses in the chain, with the
676 rightmost address being the most recent.
678 If a request reaches us from a source that is allowed by this
679 configuration item, then we consult the X-Forwarded-For header
680 to see where that host received the request from. If the
681 X-Forwarded-For header contains multiple addresses, and if
682 acl_uses_indirect_client is on, then we continue backtracking
683 until we reach an address for which we are not allowed to
684 follow the X-Forwarded-For header, or until we reach the first
685 address in the list. (If acl_uses_indirect_client is off, then
686 it's impossible to backtrack through more than one level of
687 X-Forwarded-For addresses.)
689 The end result of this process is an IP address that we will
690 refer to as the indirect client address. This address may
691 be treated as the client address for access control, delay
692 pools and logging, depending on the acl_uses_indirect_client,
693 delay_pool_uses_indirect_client and log_uses_indirect_client
696 SECURITY CONSIDERATIONS:
698 Any host for which we follow the X-Forwarded-For header
699 can place incorrect information in the header, and Squid
700 will use the incorrect information as if it were the
701 source address of the request. This may enable remote
702 hosts to bypass any access control restrictions that are
703 based on the client's source addresses.
707 acl localhost src 127.0.0.1
708 acl my_other_proxy srcdomain .proxy.example.com
709 follow_x_forwarded_for allow localhost
710 follow_x_forwarded_for allow my_other_proxy
713 NAME: acl_uses_indirect_client
716 IFDEF: FOLLOW_X_FORWARDED_FOR
718 LOC: Config.onoff.acl_uses_indirect_client
720 Controls whether the indirect client address
721 (see follow_x_forwarded_for) is used instead of the
722 direct client address in acl matching.
725 NAME: delay_pool_uses_indirect_client
728 IFDEF: FOLLOW_X_FORWARDED_FOR && DELAY_POOLS
730 LOC: Config.onoff.delay_pool_uses_indirect_client
732 Controls whether the indirect client address
733 (see follow_x_forwarded_for) is used instead of the
734 direct client address in delay pools.
737 NAME: log_uses_indirect_client
740 IFDEF: FOLLOW_X_FORWARDED_FOR
742 LOC: Config.onoff.log_uses_indirect_client
744 Controls whether the indirect client address
745 (see follow_x_forwarded_for) is used instead of the
746 direct client address in the access log.
751 LOC: Config.accessList.http
753 DEFAULT_IF_NONE: deny all
755 Allowing or Denying access based on defined access lists
757 Access to the HTTP port:
758 http_access allow|deny [!]aclname ...
760 NOTE on default values:
762 If there are no "access" lines present, the default is to deny
765 If none of the "access" lines cause a match, the default is the
766 opposite of the last line in the list. If the last line was
767 deny, the default is allow. Conversely, if the last line
768 is allow, the default will be deny. For these reasons, it is a
769 good idea to have an "deny all" or "allow all" entry at the end
770 of your access lists to avoid potential confusion.
773 #Recommended minimum configuration:
775 # Only allow cachemgr access from localhost
776 http_access allow manager localhost
777 http_access deny manager
778 # Deny requests to unknown ports
779 http_access deny !Safe_ports
780 # Deny CONNECT to other than SSL ports
781 http_access deny CONNECT !SSL_ports
783 # We strongly recommend the following be uncommented to protect innocent
784 # web applications running on the proxy server who think the only
785 # one who can access services on "localhost" is a local user
786 #http_access deny to_localhost
788 # INSERT YOUR OWN RULE(S) HERE TO ALLOW ACCESS FROM YOUR CLIENTS
790 # Example rule allowing access from your local networks.
791 # Adapt localnet in the ACL section to list your (internal) IP networks
792 # from where browsing should be allowed
793 http_access allow localnet
795 # And finally deny all other access to this proxy
800 NAME: http_reply_access
802 LOC: Config.accessList.reply
805 Allow replies to client requests. This is complementary to http_access.
807 http_reply_access allow|deny [!] aclname ...
809 NOTE: if there are no access lines present, the default is to allow
812 If none of the access lines cause a match the opposite of the
813 last line will apply. Thus it is good practice to end the rules
814 with an "allow all" or "deny all" entry.
819 LOC: Config.accessList.icp
821 DEFAULT_IF_NONE: deny all
823 Allowing or Denying access to the ICP port based on defined
826 icp_access allow|deny [!]aclname ...
828 See http_access for details
831 #Allow ICP queries from local networks only
832 icp_access allow localnet
840 LOC: Config.accessList.htcp
842 DEFAULT_IF_NONE: deny all
844 Allowing or Denying access to the HTCP port based on defined
847 htcp_access allow|deny [!]aclname ...
849 See http_access for details
851 NOTE: The default if no htcp_access lines are present is to
852 deny all traffic. This default may cause problems with peers
853 using the htcp or htcp-oldsquid options.
856 #Allow HTCP queries from local networks only
857 htcp_access allow localnet
862 NAME: htcp_clr_access
865 LOC: Config.accessList.htcp_clr
867 DEFAULT_IF_NONE: deny all
869 Allowing or Denying access to purge content using HTCP based
870 on defined access lists
872 htcp_clr_access allow|deny [!]aclname ...
874 See http_access for details
876 #Allow HTCP CLR requests from trusted peers
877 acl htcp_clr_peer src 172.16.1.2
878 htcp_clr_access allow htcp_clr_peer
883 LOC: Config.accessList.miss
886 Use to force your neighbors to use you as a sibling instead of
887 a parent. For example:
889 acl localclients src 172.16.0.0/16
890 miss_access allow localclients
891 miss_access deny !localclients
893 This means only your local clients are allowed to fetch
894 MISSES and all other clients can only fetch HITS.
896 By default, allow all clients who passed the http_access rules
897 to fetch MISSES from us.
901 # miss_access allow all
905 NAME: ident_lookup_access
909 DEFAULT_IF_NONE: deny all
910 LOC: Config.accessList.identLookup
912 A list of ACL elements which, if matched, cause an ident
913 (RFC 931) lookup to be performed for this request. For
914 example, you might choose to always perform ident lookups
915 for your main multi-user Unix boxes, but not for your Macs
916 and PCs. By default, ident lookups are not performed for
919 To enable ident lookups for specific client addresses, you
920 can follow this example:
922 acl ident_aware_hosts src 198.168.1.0/255.255.255.0
923 ident_lookup_access allow ident_aware_hosts
924 ident_lookup_access deny all
926 Only src type ACL checks are fully supported. A src_domain
927 ACL might work at times, but it will not always provide
931 NAME: reply_body_max_size
932 COMMENT: size [acl acl...]
935 LOC: Config.ReplyBodySize
937 This option specifies the maximum size of a reply body. It can be
938 used to prevent users from downloading very large files, such as
939 MP3's and movies. When the reply headers are received, the
940 reply_body_max_size lines are processed, and the first line where
941 all (if any) listed ACLs are true is used as the maximum body size
944 This size is checked twice. First when we get the reply headers,
945 we check the content-length value. If the content length value exists
946 and is larger than the allowed size, the request is denied and the
947 user receives an error message that says "the request or reply
948 is too large." If there is no content-length, and the reply
949 size exceeds this limit, the client's connection is just closed
950 and they will receive a partial reply.
952 WARNING: downstream caches probably can not detect a partial reply
953 if there is no content-length header, so they will cache
954 partial responses and give them out as hits. You should NOT
955 use this option if you have downstream caches.
957 WARNING: A maximum size smaller than the size of squid's error messages
958 will cause an infinite loop and crash squid. Ensure that the smallest
959 non-zero value you use is greater that the maximum header size plus
960 the size of your largest error page.
962 If you set this parameter none (the default), there will be
968 -----------------------------------------------------------------------------
971 NAME: http_port ascii_port
974 LOC: Config.Sockaddr.http
976 Usage: port [options]
977 hostname:port [options]
978 1.2.3.4:port [options]
980 The socket addresses where Squid will listen for HTTP client
981 requests. You may specify multiple socket addresses.
982 There are three forms: port alone, hostname with port, and
983 IP address with port. If you specify a hostname or IP
984 address, Squid binds the socket to that specific
985 address. This replaces the old 'tcp_incoming_address'
986 option. Most likely, you do not need to bind to a specific
987 address, so you can use the port number alone.
989 If you are running Squid in accelerator mode, you
990 probably want to listen on port 80 also, or instead.
992 The -a command line option may be used to specify additional
993 port(s) where Squid listens for proxy request. Such ports will
994 be plain proxy ports with no options.
996 You may specify multiple socket addresses on multiple lines.
1000 intercept Support for IP-Layer interception of
1001 outgoing requests without browser settings.
1002 NP: disables authentication and IPv6 on the port.
1004 tproxy Support Linux TPROXY for spoofing outgoing
1005 connections using the client IP address.
1006 NP: disables authentication and IPv6 on the port.
1008 accel Accelerator mode. Also needs at least one of
1009 vhost / vport / defaultsite.
1011 defaultsite=domainname
1012 What to use for the Host: header if it is not present
1013 in a request. Determines what site (not origin server)
1014 accelerators should consider the default.
1017 vhost Accelerator mode using Host header for virtual
1018 domain support. Implies accel.
1020 vport Accelerator with IP based virtual host support.
1023 vport=NN As above, but uses specified port number rather
1024 than the http_port number. Implies accel.
1026 protocol= Protocol to reconstruct accelerated requests with.
1029 disable-pmtu-discovery=
1030 Control Path-MTU discovery usage:
1031 off lets OS decide on what to do (default).
1032 transparent disable PMTU discovery when transparent
1034 always disable always PMTU discovery.
1036 In many setups of transparently intercepting proxies
1037 Path-MTU discovery can not work on traffic towards the
1038 clients. This is the case when the intercepting device
1039 does not fully track connections and fails to forward
1040 ICMP must fragment messages to the cache server. If you
1041 have such setup and experience that certain clients
1042 sporadically hang or never complete requests set
1043 disable-pmtu-discovery option to 'transparent'.
1045 sslBump Intercept each CONNECT request matching ssl_bump ACL,
1046 establish secure connection with the client and with
1047 the server, decrypt HTTP messages as they pass through
1048 Squid, and treat them as unencrypted HTTP messages,
1049 becoming the man-in-the-middle.
1051 When this option is enabled, additional options become
1052 available to specify SSL-related properties of the
1053 client-side connection: cert, key, version, cipher,
1054 options, clientca, cafile, capath, crlfile, dhparams,
1055 sslflags, and sslcontext. See the https_port directive
1056 for more information on these options.
1058 The ssl_bump option is required to fully enable
1059 the SslBump feature.
1061 name= Specifies a internal name for the port. Defaults to
1062 the port specification (port or addr:port)
1064 keepalive[=idle,interval,timeout]
1065 Enable TCP keepalive probes of idle connections
1066 idle is the initial time before TCP starts probing
1067 the connection, interval how often to probe, and
1068 timeout the time before giving up.
1070 If you run Squid on a dual-homed machine with an internal
1071 and an external interface we recommend you to specify the
1072 internal address:port in http_port. This way Squid will only be
1073 visible on the internal address.
1076 # Squid normally listens to port 3128
1077 http_port @DEFAULT_HTTP_PORT@
1083 TYPE: https_port_list
1085 LOC: Config.Sockaddr.https
1087 Usage: [ip:]port cert=certificate.pem [key=key.pem] [options...]
1089 The socket address where Squid will listen for HTTPS client
1092 This is really only useful for situations where you are running
1093 squid in accelerator mode and you want to do the SSL work at the
1096 You may specify multiple socket addresses on multiple lines,
1097 each with their own SSL certificate and/or options.
1101 accel Accelerator mode. Also needs at least one of
1102 defaultsite or vhost.
1104 defaultsite= The name of the https site presented on
1105 this port. Implies accel.
1107 vhost Accelerator mode using Host header for virtual
1108 domain support. Requires a wildcard certificate
1109 or other certificate valid for more than one domain.
1112 protocol= Protocol to reconstruct accelerated requests with.
1115 cert= Path to SSL certificate (PEM format).
1117 key= Path to SSL private key file (PEM format)
1118 if not specified, the certificate file is
1119 assumed to be a combined certificate and
1122 version= The version of SSL/TLS supported
1123 1 automatic (default)
1128 cipher= Colon separated list of supported ciphers.
1130 options= Various SSL engine options. The most important
1132 NO_SSLv2 Disallow the use of SSLv2
1133 NO_SSLv3 Disallow the use of SSLv3
1134 NO_TLSv1 Disallow the use of TLSv1
1135 SINGLE_DH_USE Always create a new key when using
1136 temporary/ephemeral DH key exchanges
1137 See src/ssl_support.c or OpenSSL SSL_CTX_set_options
1138 documentation for a complete list of options.
1140 clientca= File containing the list of CAs to use when
1141 requesting a client certificate.
1143 cafile= File containing additional CA certificates to
1144 use when verifying client certificates. If unset
1145 clientca will be used.
1147 capath= Directory containing additional CA certificates
1148 and CRL lists to use when verifying client certificates.
1150 crlfile= File of additional CRL lists to use when verifying
1151 the client certificate, in addition to CRLs stored in
1152 the capath. Implies VERIFY_CRL flag below.
1154 dhparams= File containing DH parameters for temporary/ephemeral
1157 sslflags= Various flags modifying the use of SSL:
1159 Don't request client certificates
1160 immediately, but wait until acl processing
1161 requires a certificate (not yet implemented).
1163 Don't use the default CA lists built in
1166 Don't allow for session reuse. Each connection
1167 will result in a new SSL session.
1169 Verify CRL lists when accepting client
1172 Verify CRL lists for all certificates in the
1173 client certificate chain.
1175 sslcontext= SSL session ID context identifier.
1177 vport Accelerator with IP based virtual host support.
1179 vport=NN As above, but uses specified port number rather
1180 than the https_port number. Implies accel.
1182 name= Specifies a internal name for the port. Defaults to
1183 the port specification (port or addr:port)
1187 NAME: tcp_outgoing_tos tcp_outgoing_ds tcp_outgoing_dscp
1190 LOC: Config.accessList.outgoing_tos
1192 Allows you to select a TOS/Diffserv value to mark outgoing
1193 connections with, based on the username or source address
1196 tcp_outgoing_tos ds-field [!]aclname ...
1198 Example where normal_service_net uses the TOS value 0x00
1199 and normal_service_net uses 0x20
1201 acl normal_service_net src 10.0.0.0/255.255.255.0
1202 acl good_service_net src 10.0.1.0/255.255.255.0
1203 tcp_outgoing_tos 0x00 normal_service_net
1204 tcp_outgoing_tos 0x20 good_service_net
1206 TOS/DSCP values really only have local significance - so you should
1207 know what you're specifying. For more information, see RFC2474 and
1210 The TOS/DSCP byte must be exactly that - a octet value 0 - 255, or
1211 "default" to use whatever default your host has. Note that in
1212 practice often only values 0 - 63 is usable as the two highest bits
1213 have been redefined for use by ECN (RFC3168).
1215 Processing proceeds in the order specified, and stops at first fully
1218 Note: The use of this directive using client dependent ACLs is
1219 incompatible with the use of server side persistent connections. To
1220 ensure correct results it is best to set server_persisten_connections
1221 to off when using this directive in such configurations.
1224 NAME: clientside_tos
1227 LOC: Config.accessList.clientside_tos
1229 Allows you to select a TOS/Diffserv value to mark client-side
1230 connections with, based on the username or source address
1238 LOC: Config.zph_tos_local
1240 Allows you to select a TOS/Diffserv value to mark local hits. Read above
1241 (tcp_outgoing_tos) for details/requirements about TOS.
1242 Default: 0 (disabled).
1249 LOC: Config.zph_tos_peer
1251 Allows you to select a TOS/Diffserv value to mark peer hits. Read above
1252 (tcp_outgoing_tos) for details/requirements about TOS.
1253 Default: 0 (disabled).
1256 NAME: zph_tos_parent
1261 LOC: Config.onoff.zph_tos_parent
1263 Set this to off if you want only sibling hits to be marked.
1264 If set to on (default), parent hits are being marked too.
1267 NAME: zph_preserve_miss_tos
1272 LOC: Config.onoff.zph_preserve_miss_tos
1274 If set to on (default), any HTTP response towards clients will
1275 have the TOS value of the response comming from the remote
1276 server masked with the value of zph_preserve_miss_tos_mask.
1277 For this to work correctly, you will need to patch your linux
1278 kernel with the TOS preserving ZPH patch.
1279 The kernel patch can be downloaded from http://zph.bratcheda.org
1282 NAME: zph_preserve_miss_tos_mask
1286 LOC: Config.zph_preserve_miss_tos_mask
1288 Allows you to mask certain bits in the TOS received from the
1289 remote server, before copying the value to the TOS send towards
1291 Default: 255 (TOS from server is not changed).
1294 NAME: tcp_outgoing_address
1297 LOC: Config.accessList.outgoing_address
1299 Allows you to map requests to different outgoing IP addresses
1300 based on the username or source address of the user making
1303 tcp_outgoing_address ipaddr [[!]aclname] ...
1305 Example where requests from 10.0.0.0/24 will be forwarded
1306 with source address 10.1.0.1, 10.0.2.0/24 forwarded with
1307 source address 10.1.0.2 and the rest will be forwarded with
1308 source address 10.1.0.3.
1310 acl normal_service_net src 10.0.0.0/24
1311 acl good_service_net src 10.0.2.0/24
1312 tcp_outgoing_address 10.1.0.1 normal_service_net
1313 tcp_outgoing_address 10.1.0.2 good_service_net
1314 tcp_outgoing_address 10.1.0.3
1316 Processing proceeds in the order specified, and stops at first fully
1319 Note: The use of this directive using client dependent ACLs is
1320 incompatible with the use of server side persistent connections. To
1321 ensure correct results it is best to set server_persistent_connections
1322 to off when using this directive in such configurations.
1327 Squid is built with a capability of bridging the IPv4 and IPv6 internets.
1328 tcp_outgoing_address as exampled above breaks this bridging by forcing
1329 all outbound traffic through a certain IPv4 which may be on the wrong
1330 side of the IPv4/IPv6 boundary.
1332 To operate with tcp_outgoing_address and keep the bridging benefits
1333 an additional ACL needs to be used which ensures the IPv6-bound traffic
1334 is never forced or permitted out the IPv4 interface.
1336 acl to_ipv6 dst ipv6
1337 tcp_outgoing_address 2002::c001 good_service_net to_ipv6
1338 tcp_outgoing_address 10.1.0.2 good_service_net !to_ipv6
1340 tcp_outgoing_address 2002::beef normal_service_net to_ipv6
1341 tcp_outgoing_address 10.1.0.1 normal_service_net !to_ipv6
1343 tcp_outgoing_address 2002::1 to_ipv6
1344 tcp_outgoing_address 10.1.0.3 !to_ipv6
1349 -----------------------------------------------------------------------------
1352 NAME: ssl_unclean_shutdown
1356 LOC: Config.SSL.unclean_shutdown
1358 Some browsers (especially MSIE) bugs out on SSL shutdown
1365 LOC: Config.SSL.ssl_engine
1368 The OpenSSL engine to use. You will need to set this if you
1369 would like to use hardware SSL acceleration for example.
1372 NAME: sslproxy_client_certificate
1375 LOC: Config.ssl_client.cert
1378 Client SSL Certificate to use when proxying https:// URLs
1381 NAME: sslproxy_client_key
1384 LOC: Config.ssl_client.key
1387 Client SSL Key to use when proxying https:// URLs
1390 NAME: sslproxy_version
1393 LOC: Config.ssl_client.version
1396 SSL version level to use when proxying https:// URLs
1399 NAME: sslproxy_options
1402 LOC: Config.ssl_client.options
1405 SSL engine options to use when proxying https:// URLs
1408 NAME: sslproxy_cipher
1411 LOC: Config.ssl_client.cipher
1414 SSL cipher list to use when proxying https:// URLs
1417 NAME: sslproxy_cafile
1420 LOC: Config.ssl_client.cafile
1423 file containing CA certificates to use when verifying server
1424 certificates while proxying https:// URLs
1427 NAME: sslproxy_capath
1430 LOC: Config.ssl_client.capath
1433 directory containing CA certificates to use when verifying
1434 server certificates while proxying https:// URLs
1440 LOC: Config.accessList.ssl_bump
1443 This ACL controls which CONNECT requests to an http_port
1444 marked with an sslBump flag are actually "bumped". Please
1445 see the sslBump flag of an http_port option for more details
1446 about decoding proxied SSL connections.
1448 By default, no requests are bumped.
1450 See also: http_port sslBump
1453 # Example: Bump all requests except those originating from localhost and
1454 # those going to webax.com or example.com sites.
1456 # acl localhost src 127.0.0.1/32
1457 # acl broken_sites dstdomain .webax.com
1458 # acl broken_sites dstdomain .example.com
1459 # ssl_bump deny localhost
1460 # ssl_bump deny broken_sites
1461 # ssl_bump allow all
1465 NAME: sslproxy_flags
1468 LOC: Config.ssl_client.flags
1471 Various flags modifying the use of SSL while proxying https:// URLs:
1472 DONT_VERIFY_PEER Accept certificates that fail verification.
1473 For refined control, see sslproxy_cert_error.
1474 NO_DEFAULT_CA Don't use the default CA list built in
1479 NAME: sslproxy_cert_error
1482 LOC: Config.ssl_client.cert_error
1485 Use this ACL to bypass server certificate validation errors.
1487 For example, the following lines will bypass all validation errors
1488 when talking to servers located at 172.16.0.0/16. All other
1489 validation errors will result in ERR_SECURE_CONNECT_FAIL error.
1491 acl BrokenServersAtTrustedIP dst 172.16.0.0/16
1492 sslproxy_cert_error allow BrokenServersAtTrustedIP
1493 sslproxy_cert_error deny all
1495 This option must use fast ACL expressions only. Expressions that use
1496 external lookups or communication result in unpredictable behavior or
1499 Without this option, all server certificate validation errors
1500 terminate the transaction. Bypassing validation errors is dangerous
1501 because an error usually implies that the server cannot be trusted and
1502 the connection may be insecure.
1504 See also: sslproxy_flags and DONT_VERIFY_PEER.
1508 # sslproxy_cert_error deny all
1514 NAME: sslpassword_program
1517 LOC: Config.Program.ssl_password
1520 Specify a program used for entering SSL key passphrases
1521 when using encrypted SSL certificate keys. If not specified
1522 keys must either be unencrypted, or Squid started with the -N
1523 option to allow it to query interactively for the passphrase.
1527 OPTIONS WHICH AFFECT THE NEIGHBOR SELECTION ALGORITHM
1528 -----------------------------------------------------------------------------
1536 To specify other caches in a hierarchy, use the format:
1538 cache_peer hostname type http-port icp-port [options]
1543 # hostname type port port options
1544 # -------------------- -------- ----- ----- -----------
1545 cache_peer parent.foo.net parent 3128 3130 proxy-only default
1546 cache_peer sib1.foo.net sibling 3128 3130 proxy-only
1547 cache_peer sib2.foo.net sibling 3128 3130 proxy-only
1549 type: either 'parent', 'sibling', or 'multicast'.
1551 proxy-port: The port number where the cache listens for proxy
1554 icp-port: Used for querying neighbor caches about
1555 objects. To have a non-ICP neighbor
1556 specify '7' for the ICP port and make sure the
1557 neighbor machine has the UDP echo port
1558 enabled in its /etc/inetd.conf file.
1559 NOTE: Also requires icp_port option enabled to send/receive
1560 requests via this method.
1570 weighted-round-robin
1577 login=user:password | PASS | *:password
1588 sslcert=/path/to/ssl/certificate
1589 sslkey=/path/to/ssl/key
1593 front-end-https[=on|auto]
1595 use 'proxy-only' to specify objects fetched
1596 from this cache should not be saved locally.
1598 use 'weight=n' to affect the selection of a peer
1599 during any weighted peer-selection mechanisms.
1600 The weight must be an integer; default is 1,
1601 larger weights are favored more.
1602 This option does not affect parent selection if a peering
1603 protocol is not in use.
1605 use 'basetime=n' to specify a base amount to
1606 be subtracted from round trip times of parents.
1607 It is subtracted before division by weight in calculating
1608 which parent to fectch from. If the rtt is less than the
1609 base time the rtt is set to a minimal value.
1611 use 'ttl=n' to specify a IP multicast TTL to use
1612 when sending an ICP queries to this address.
1613 Only useful when sending to a multicast group.
1614 Because we don't accept ICP replies from random
1615 hosts, you must configure other group members as
1616 peers with the 'multicast-responder' option below.
1618 use 'no-query' to NOT send ICP queries to this
1621 use 'background-ping' to only send ICP queries to this
1622 neighbor infrequently. This is used to keep the neighbor
1623 round trip time updated and is usually used in
1624 conjunction with weighted-round-robin.
1626 use 'default' if this is a parent cache which can
1627 be used as a "last-resort" if a peer cannot be located
1628 by any of the peer-selection mechanisms.
1629 If specified more than once, only the first is used.
1631 use 'round-robin' to define a set of parents which
1632 should be used in a round-robin fashion in the
1633 absence of any ICP queries.
1635 use 'weighted-round-robin' to define a set of parents
1636 which should be used in a round-robin fashion with the
1637 frequency of each parent being based on the round trip
1638 time. Closer parents are used more often.
1639 Usually used for background-ping parents.
1641 use 'carp' to define a set of parents which should
1642 be used as a CARP array. The requests will be
1643 distributed among the parents based on the CARP load
1644 balancing hash function based on their weight.
1646 'multicast-responder' indicates the named peer
1647 is a member of a multicast group. ICP queries will
1648 not be sent directly to the peer, but ICP replies
1649 will be accepted from it.
1651 'closest-only' indicates that, for ICP_OP_MISS
1652 replies, we'll only forward CLOSEST_PARENT_MISSes
1653 and never FIRST_PARENT_MISSes.
1655 use 'no-digest' to NOT request cache digests from
1658 'no-netdb-exchange' disables requesting ICMP
1659 RTT database (NetDB) from the neighbor.
1661 use 'no-delay' to prevent access to this neighbor
1662 from influencing the delay pools.
1664 use 'login=user:password' if this is a personal/workgroup
1665 proxy and your parent requires proxy authentication.
1666 Note: The string can include URL escapes (i.e. %20 for
1667 spaces). This also means % must be written as %%.
1669 use 'login=PASS' if users must authenticate against
1670 the upstream proxy or in the case of a reverse proxy
1671 configuration, the origin web server. This will pass
1672 the users credentials as they are to the peer.
1673 This only works for the Basic HTTP authentication scheme.
1674 Note: To combine this with proxy_auth both proxies must
1675 share the same user database as HTTP only allows for
1676 a single login (one for proxy, one for origin server).
1677 Also be warned this will expose your users proxy
1678 password to the peer. USE WITH CAUTION
1680 use 'login=*:password' to pass the username to the
1681 upstream cache, but with a fixed password. This is meant
1682 to be used when the peer is in another administrative
1683 domain, but it is still needed to identify each user.
1684 The star can optionally be followed by some extra
1685 information which is added to the username. This can
1686 be used to identify this proxy to the peer, similar to
1687 the login=username:password option above.
1689 use 'connect-timeout=nn' to specify a peer
1690 specific connect timeout (also see the
1691 peer_connect_timeout directive)
1693 use 'digest-url=url' to tell Squid to fetch the cache
1694 digest (if digests are enabled) for this host from
1695 the specified URL rather than the Squid default
1698 use 'allow-miss' to disable Squid's use of only-if-cached
1699 when forwarding requests to siblings. This is primarily
1700 useful when icp_hit_stale is used by the sibling. To
1701 extensive use of this option may result in forwarding
1702 loops, and you should avoid having two-way peerings
1703 with this option. (for example to deny peer usage on
1704 requests from peer by denying cache_peer_access if the
1707 use 'max-conn=n' to limit the amount of connections Squid
1708 may open to this peer.
1710 use 'htcp' to send HTCP, instead of ICP, queries
1711 to the neighbor. You probably also want to
1712 set the "icp port" to 4827 instead of 3130.
1713 You MUST also set htcp_access expicitly. The default of
1714 deny all will prevent peer traffic.
1716 use 'htcp-oldsquid' to send HTCP to old Squid versions
1717 You MUST also set htcp_access expicitly. The default of
1718 deny all will prevent peer traffic.
1720 'originserver' causes this parent peer to be contacted as
1721 a origin server. Meant to be used in accelerator setups.
1723 use 'name=xxx' if you have multiple peers on the same
1724 host but different ports. This name can be used to
1725 differentiate the peers in cache_peer_access and similar
1728 use 'forceddomain=name' to forcibly set the Host header
1729 of requests forwarded to this peer. Useful in accelerator
1730 setups where the server (peer) expects a certain domain
1731 name and using redirectors to feed this domain name
1734 use 'ssl' to indicate connections to this peer should
1735 be SSL/TLS encrypted.
1737 use 'sslcert=/path/to/ssl/certificate' to specify a client
1738 SSL certificate to use when connecting to this peer.
1740 use 'sslkey=/path/to/ssl/key' to specify the private SSL
1741 key corresponding to sslcert above. If 'sslkey' is not
1742 specified 'sslcert' is assumed to reference a
1743 combined file containing both the certificate and the key.
1745 use sslversion=1|2|3|4 to specify the SSL version to use
1746 when connecting to this peer
1747 1 = automatic (default)
1752 use sslcipher=... to specify the list of valid SSL ciphers
1753 to use when connecting to this peer.
1755 use ssloptions=... to specify various SSL engine options:
1756 NO_SSLv2 Disallow the use of SSLv2
1757 NO_SSLv3 Disallow the use of SSLv3
1758 NO_TLSv1 Disallow the use of TLSv1
1759 See src/ssl_support.c or the OpenSSL documentation for
1760 a more complete list.
1762 use sslcafile=... to specify a file containing
1763 additional CA certificates to use when verifying the
1766 use sslcapath=... to specify a directory containing
1767 additional CA certificates to use when verifying the
1770 use sslcrlfile=... to specify a certificate revocation
1771 list file to use when verifying the peer certificate.
1773 use sslflags=... to specify various flags modifying the
1776 Accept certificates even if they fail to
1779 Don't use the default CA list built in
1782 Don't verify the peer certificate
1783 matches the server name
1785 use ssldomain= to specify the peer name as advertised
1786 in it's certificate. Used for verifying the correctness
1787 of the received peer certificate. If not specified the
1788 peer hostname will be used.
1790 use front-end-https to enable the "Front-End-Https: On"
1791 header needed when using Squid as a SSL frontend in front
1792 of Microsoft OWA. See MS KB document Q307347 for details
1793 on this header. If set to auto the header will
1794 only be added if the request is forwarded as a https://
1798 NAME: cache_peer_domain cache_host_domain
1803 Use to limit the domains for which a neighbor cache will be
1806 cache_peer_domain cache-host domain [domain ...]
1807 cache_peer_domain cache-host !domain
1809 For example, specifying
1811 cache_peer_domain parent.foo.net .edu
1813 has the effect such that UDP query packets are sent to
1814 'bigserver' only when the requested object exists on a
1815 server in the .edu domain. Prefixing the domainname
1816 with '!' means the cache will be queried for objects
1819 NOTE: * Any number of domains may be given for a cache-host,
1820 either on the same or separate lines.
1821 * When multiple domains are given for a particular
1822 cache-host, the first matched domain is applied.
1823 * Cache hosts with no domain restrictions are queried
1825 * There are no defaults.
1826 * There is also a 'cache_peer_access' tag in the ACL
1830 NAME: cache_peer_access
1835 Similar to 'cache_peer_domain' but provides more flexibility by
1838 cache_peer_access cache-host allow|deny [!]aclname ...
1840 The syntax is identical to 'http_access' and the other lists of
1841 ACL elements. See the comments for 'http_access' below, or
1842 the Squid FAQ (http://www.squid-cache.org/FAQ/FAQ-10.html).
1845 NAME: neighbor_type_domain
1846 TYPE: hostdomaintype
1850 usage: neighbor_type_domain neighbor parent|sibling domain domain ...
1852 Modifying the neighbor type for specific domains is now
1853 possible. You can treat some domains differently than the the
1854 default neighbor type specified on the 'cache_peer' line.
1855 Normally it should only be necessary to list domains which
1856 should be treated differently because the default neighbor type
1857 applies for hostnames which do not match domains listed here.
1860 cache_peer cache.foo.org parent 3128 3130
1861 neighbor_type_domain cache.foo.org sibling .com .net
1862 neighbor_type_domain cache.foo.org sibling .au .de
1865 NAME: dead_peer_timeout
1869 LOC: Config.Timeout.deadPeer
1871 This controls how long Squid waits to declare a peer cache
1872 as "dead." If there are no ICP replies received in this
1873 amount of time, Squid will declare the peer dead and not
1874 expect to receive any further ICP replies. However, it
1875 continues to send ICP queries, and will mark the peer as
1876 alive upon receipt of the first subsequent ICP reply.
1878 This timeout also affects when Squid expects to receive ICP
1879 replies from peers. If more than 'dead_peer' seconds have
1880 passed since the last ICP reply was received, Squid will not
1881 expect to receive an ICP reply on the next query. Thus, if
1882 your time between requests is greater than this timeout, you
1883 will see a lot of requests sent DIRECT to origin servers
1884 instead of to your parents.
1887 NAME: hierarchy_stoplist
1890 LOC: Config.hierarchy_stoplist
1892 A list of words which, if found in a URL, cause the object to
1893 be handled directly by this cache. In other words, use this
1894 to not query neighbor caches for certain objects. You may
1895 list this option multiple times.
1896 Note: never_direct overrides this option.
1898 #We recommend you to use at least the following line.
1899 hierarchy_stoplist cgi-bin ?
1904 MEMORY CACHE OPTIONS
1905 -----------------------------------------------------------------------------
1912 LOC: Config.memMaxSize
1914 NOTE: THIS PARAMETER DOES NOT SPECIFY THE MAXIMUM PROCESS SIZE.
1915 IT ONLY PLACES A LIMIT ON HOW MUCH ADDITIONAL MEMORY SQUID WILL
1916 USE AS A MEMORY CACHE OF OBJECTS. SQUID USES MEMORY FOR OTHER
1917 THINGS AS WELL. SEE THE SQUID FAQ SECTION 8 FOR DETAILS.
1919 'cache_mem' specifies the ideal amount of memory to be used
1921 * In-Transit objects
1923 * Negative-Cached objects
1925 Data for these objects are stored in 4 KB blocks. This
1926 parameter specifies the ideal upper limit on the total size of
1927 4 KB blocks allocated. In-Transit objects take the highest
1930 In-transit objects have priority over the others. When
1931 additional space is needed for incoming data, negative-cached
1932 and hot objects will be released. In other words, the
1933 negative-cached and hot objects will fill up any unused space
1934 not needed for in-transit objects.
1936 If circumstances require, this limit will be exceeded.
1937 Specifically, if your incoming request rate requires more than
1938 'cache_mem' of memory to hold in-transit objects, Squid will
1939 exceed this limit to satisfy the new requests. When the load
1940 decreases, blocks will be freed until the high-water mark is
1941 reached. Thereafter, blocks will be used to store hot
1945 NAME: maximum_object_size_in_memory
1949 LOC: Config.Store.maxInMemObjSize
1951 Objects greater than this size will not be attempted to kept in
1952 the memory cache. This should be set high enough to keep objects
1953 accessed frequently in memory to improve performance whilst low
1954 enough to keep larger objects from hoarding cache_mem.
1957 NAME: memory_replacement_policy
1959 LOC: Config.memPolicy
1962 The memory replacement policy parameter determines which
1963 objects are purged from memory when memory space is needed.
1965 See cache_replacement_policy for details.
1970 -----------------------------------------------------------------------------
1973 NAME: cache_replacement_policy
1975 LOC: Config.replPolicy
1978 The cache replacement policy parameter determines which
1979 objects are evicted (replaced) when disk space is needed.
1981 lru : Squid's original list based LRU policy
1982 heap GDSF : Greedy-Dual Size Frequency
1983 heap LFUDA: Least Frequently Used with Dynamic Aging
1984 heap LRU : LRU policy implemented using a heap
1986 Applies to any cache_dir lines listed below this.
1988 The LRU policies keeps recently referenced objects.
1990 The heap GDSF policy optimizes object hit rate by keeping smaller
1991 popular objects in cache so it has a better chance of getting a
1992 hit. It achieves a lower byte hit rate than LFUDA though since
1993 it evicts larger (possibly popular) objects.
1995 The heap LFUDA policy keeps popular objects in cache regardless of
1996 their size and thus optimizes byte hit rate at the expense of
1997 hit rate since one large, popular object will prevent many
1998 smaller, slightly less popular objects from being cached.
2000 Both policies utilize a dynamic aging mechanism that prevents
2001 cache pollution that can otherwise occur with frequency-based
2002 replacement policies.
2004 NOTE: if using the LFUDA replacement policy you should increase
2005 the value of maximum_object_size above its default of 4096 KB to
2006 to maximize the potential byte hit rate improvement of LFUDA.
2008 For more information about the GDSF and LFUDA cache replacement
2009 policies see http://www.hpl.hp.com/techreports/1999/HPL-1999-69.html
2010 and http://fog.hpl.external.hp.com/techreports/98/HPL-98-173.html.
2016 LOC: Config.cacheSwap
2020 cache_dir Type Directory-Name Fs-specific-data [options]
2022 You can specify multiple cache_dir lines to spread the
2023 cache among different disk partitions.
2025 Type specifies the kind of storage system to use. Only "ufs"
2026 is built by default. To enable any of the other storage systems
2027 see the --enable-storeio configure option.
2029 'Directory' is a top-level directory where cache swap
2030 files will be stored. If you want to use an entire disk
2031 for caching, this can be the mount-point directory.
2032 The directory must exist and be writable by the Squid
2033 process. Squid will NOT create this directory for you.
2037 "ufs" is the old well-known Squid storage format that has always
2040 cache_dir ufs Directory-Name Mbytes L1 L2 [options]
2042 'Mbytes' is the amount of disk space (MB) to use under this
2043 directory. The default is 100 MB. Change this to suit your
2044 configuration. Do NOT put the size of your disk drive here.
2045 Instead, if you want Squid to use the entire disk drive,
2046 subtract 20% and use that value.
2048 'Level-1' is the number of first-level subdirectories which
2049 will be created under the 'Directory'. The default is 16.
2051 'Level-2' is the number of second-level subdirectories which
2052 will be created under each first-level directory. The default
2055 The aufs store type:
2057 "aufs" uses the same storage format as "ufs", utilizing
2058 POSIX-threads to avoid blocking the main Squid process on
2059 disk-I/O. This was formerly known in Squid as async-io.
2061 cache_dir aufs Directory-Name Mbytes L1 L2 [options]
2063 see argument descriptions under ufs above
2065 The diskd store type:
2067 "diskd" uses the same storage format as "ufs", utilizing a
2068 separate process to avoid blocking the main Squid process on
2071 cache_dir diskd Directory-Name Mbytes L1 L2 [options] [Q1=n] [Q2=n]
2073 see argument descriptions under ufs above
2075 Q1 specifies the number of unacknowledged I/O requests when Squid
2076 stops opening new files. If this many messages are in the queues,
2077 Squid won't open new files. Default is 64
2079 Q2 specifies the number of unacknowledged messages when Squid
2080 starts blocking. If this many messages are in the queues,
2081 Squid blocks until it receives some replies. Default is 72
2083 When Q1 < Q2 (the default), the cache directory is optimized
2084 for lower response time at the expense of a decrease in hit
2085 ratio. If Q1 > Q2, the cache directory is optimized for
2086 higher hit ratio at the expense of an increase in response
2089 The coss store type:
2091 block-size=n defines the "block size" for COSS cache_dir's.
2092 Squid uses file numbers as block numbers. Since file numbers
2093 are limited to 24 bits, the block size determines the maximum
2094 size of the COSS partition. The default is 512 bytes, which
2095 leads to a maximum cache_dir size of 512<<24, or 8 GB. Note
2096 you should not change the coss block size after Squid
2097 has written some objects to the cache_dir.
2099 The coss file store has changed from 2.5. Now it uses a file
2100 called 'stripe' in the directory names in the config - and
2101 this will be created by squid -z.
2105 no-store, no new objects should be stored to this cache_dir
2107 max-size=n, refers to the max object size this storedir supports.
2108 It is used to initially choose the storedir to dump the object.
2109 Note: To make optimal use of the max-size limits you should order
2110 the cache_dir lines with the smallest max-size value first and the
2111 ones with no max-size specification last.
2113 Note for coss, max-size must be less than COSS_MEMBUF_SZ,
2114 which can be changed with the --with-coss-membuf-size=N configure
2117 cache_dir ufs @DEFAULT_SWAP_DIR@ 100 16 256
2121 NAME: store_dir_select_algorithm
2123 LOC: Config.store_dir_select_algorithm
2126 Set this to 'round-robin' as an alternative.
2129 NAME: max_open_disk_fds
2131 LOC: Config.max_open_disk_fds
2134 To avoid having disk as the I/O bottleneck Squid can optionally
2135 bypass the on-disk cache if more than this amount of disk file
2136 descriptors are open.
2138 A value of 0 indicates no limit.
2141 NAME: minimum_object_size
2145 LOC: Config.Store.minObjectSize
2147 Objects smaller than this size will NOT be saved on disk. The
2148 value is specified in kilobytes, and the default is 0 KB, which
2149 means there is no minimum.
2152 NAME: maximum_object_size
2156 LOC: Config.Store.maxObjectSize
2158 Objects larger than this size will NOT be saved on disk. The
2159 value is specified in kilobytes, and the default is 4MB. If
2160 you wish to get a high BYTES hit ratio, you should probably
2161 increase this (one 32 MB object hit counts for 3200 10KB
2162 hits). If you wish to increase speed more than your want to
2163 save bandwidth you should leave this low.
2165 NOTE: if using the LFUDA replacement policy you should increase
2166 this value to maximize the byte hit rate improvement of LFUDA!
2167 See replacement_policy below for a discussion of this policy.
2170 NAME: cache_swap_low
2171 COMMENT: (percent, 0-100)
2174 LOC: Config.Swap.lowWaterMark
2177 NAME: cache_swap_high
2178 COMMENT: (percent, 0-100)
2181 LOC: Config.Swap.highWaterMark
2184 The low- and high-water marks for cache object replacement.
2185 Replacement begins when the swap (disk) usage is above the
2186 low-water mark and attempts to maintain utilization near the
2187 low-water mark. As swap utilization gets close to high-water
2188 mark object eviction becomes more aggressive. If utilization is
2189 close to the low-water mark less replacement is done each time.
2191 Defaults are 90% and 95%. If you have a large cache, 5% could be
2192 hundreds of MB. If this is the case you may wish to set these
2193 numbers closer together.
2198 -----------------------------------------------------------------------------
2203 LOC: Config.Log.logformats
2208 logformat <name> <format specification>
2210 Defines an access log format.
2212 The <format specification> is a string with embedded % format codes
2214 % format codes all follow the same basic structure where all but
2215 the formatcode is optional. Output strings are automatically escaped
2216 as required according to their context and the output format
2217 modifiers are usually not needed, but can be specified if an explicit
2218 output format is desired.
2220 % ["|[|'|#] [-] [[0]width] [{argument}] formatcode
2222 " output in quoted string format
2223 [ output in squid text log format as used by log_mime_hdrs
2224 # output in URL quoted format
2228 width field width. If starting with 0 the
2229 output is zero padded
2230 {arg} argument such as header name etc
2234 >a Client source IP address
2236 >p Client source port
2237 <A Server IP address or peer name
2238 la Local IP address (http_port)
2239 lp Local port number (http_port)
2240 ts Seconds since epoch
2241 tu subsecond time (milliseconds)
2242 tl Local time. Optional strftime format argument
2243 default %d/%b/%Y:%H:%M:%S %z
2244 tg GMT time. Optional strftime format argument
2245 default %d/%b/%Y:%H:%M:%S %z
2246 tr Response time (milliseconds)
2247 >h Request header. Optional header name argument
2248 on the format header[:[separator]element]
2249 <h Reply header. Optional header name argument
2252 ul User name from authentication
2253 ui User name from ident
2254 us User name from SSL
2255 ue User name from external acl helper
2257 Ss Squid request status (TCP_MISS etc)
2258 Sh Squid hierarchy status (DEFAULT_PARENT etc)
2259 mt MIME content type
2260 rm Request method (GET/POST etc)
2262 rp Request URL-Path excluding hostname
2263 rv Request protocol version
2264 et Tag returned by external acl
2265 ea Log string returned by external acl
2266 <st Reply size including HTTP headers
2267 <sH Reply high offset sent
2268 <sS Upstream object size
2269 % a literal % character
2271 logformat squid %ts.%03tu %6tr %>a %Ss/%03Hs %<st %rm %ru %un %Sh/%<A %mt
2272 logformat squidmime %ts.%03tu %6tr %>a %Ss/%03Hs %<st %rm %ru %un %Sh/%<A %mt [%>h] [%<h]
2273 logformat common %>a %ui %un [%tl] "%rm %ru HTTP/%rv" %Hs %<st %Ss:%Sh
2274 logformat combined %>a %ui %un [%tl] "%rm %ru HTTP/%rv" %Hs %<st "%{Referer}>h" "%{User-Agent}>h" %Ss:%Sh
2277 NAME: access_log cache_access_log
2279 LOC: Config.Log.accesslogs
2282 These files log client request activities. Has a line every HTTP or
2283 ICP request. The format is:
2284 access_log <filepath> [<logformat name> [acl acl ...]]
2285 access_log none [acl acl ...]]
2287 Will log to the specified file using the specified format (which
2288 must be defined in a logformat directive) those entries which match
2289 ALL the acl's specified (which must be defined in acl clauses).
2290 If no acl is specified, all requests will be logged to this file.
2292 To disable logging of a request use the filepath "none", in which case
2293 a logformat name should not be specified.
2295 To log the request via syslog specify a filepath of "syslog":
2297 access_log syslog[:facility.priority] [format [acl1 [acl2 ....]]]
2298 where facility could be any of:
2299 authpriv, daemon, local0 .. local7 or user.
2301 And priority could be any of:
2302 err, warning, notice, info, debug.
2304 access_log @DEFAULT_ACCESS_LOG@ squid
2310 LOC: Config.accessList.log
2312 COMMENT: allow|deny acl acl...
2314 This options allows you to control which requests gets logged
2315 to access.log (see access_log directive). Requests denied for
2316 logging will also not be accounted for in performance counters.
2321 DEFAULT: @DEFAULT_CACHE_LOG@
2324 Cache logging file. This is where general information about
2325 your cache's behavior goes. You can increase the amount of data
2326 logged to this file with the "debug_options" tag below.
2329 NAME: cache_store_log
2331 DEFAULT: @DEFAULT_STORE_LOG@
2332 LOC: Config.Log.store
2334 Logs the activities of the storage manager. Shows which
2335 objects are ejected from the cache, and which objects are
2336 saved and for how long. To disable, enter "none". There are
2337 not really utilities to analyze this data, so you can safely
2341 NAME: cache_swap_state cache_swap_log
2343 LOC: Config.Log.swap
2346 Location for the cache "swap.state" file. This index file holds
2347 the metadata of objects saved on disk. It is used to rebuild
2348 the cache during startup. Normally this file resides in each
2349 'cache_dir' directory, but you may specify an alternate
2350 pathname here. Note you must give a full filename, not just
2351 a directory. Since this is the index for the whole object
2352 list you CANNOT periodically rotate it!
2354 If %s can be used in the file name it will be replaced with a
2355 a representation of the cache_dir name where each / is replaced
2356 with '.'. This is needed to allow adding/removing cache_dir
2357 lines when cache_swap_log is being used.
2359 If have more than one 'cache_dir', and %s is not used in the name
2360 these swap logs will have names such as:
2366 The numbered extension (which is added automatically)
2367 corresponds to the order of the 'cache_dir' lines in this
2368 configuration file. If you change the order of the 'cache_dir'
2369 lines in this file, these index files will NOT correspond to
2370 the correct 'cache_dir' entry (unless you manually rename
2371 them). We recommend you do NOT use this option. It is
2372 better to keep these index files in each 'cache_dir' directory.
2375 NAME: logfile_rotate
2378 LOC: Config.Log.rotateNumber
2380 Specifies the number of logfile rotations to make when you
2381 type 'squid -k rotate'. The default is 10, which will rotate
2382 with extensions 0 through 9. Setting logfile_rotate to 0 will
2383 disable the file name rotation, but the logfiles are still closed
2384 and re-opened. This will enable you to rename the logfiles
2385 yourself just before sending the rotate signal.
2387 Note, the 'squid -k rotate' command normally sends a USR1
2388 signal to the running squid process. In certain situations
2389 (e.g. on Linux with Async I/O), USR1 is used for other
2390 purposes, so -k rotate uses another signal. It is best to get
2391 in the habit of using 'squid -k rotate' instead of 'kill -USR1
2395 NAME: emulate_httpd_log
2399 LOC: Config.onoff.common_log
2401 The Cache can emulate the log file format which many 'httpd'
2402 programs use. To disable/enable this emulation, set
2403 emulate_httpd_log to 'off' or 'on'. The default
2404 is to use the native log format since it includes useful
2405 information Squid-specific log analyzers use.
2408 NAME: log_ip_on_direct
2412 LOC: Config.onoff.log_ip_on_direct
2414 Log the destination IP address in the hierarchy log tag when going
2415 direct. Earlier Squid versions logged the hostname here. If you
2416 prefer the old way set this to off.
2421 DEFAULT: @DEFAULT_MIME_TABLE@
2422 LOC: Config.mimeTablePathname
2424 Pathname to Squid's MIME table. You shouldn't need to change
2425 this, but the default file contains examples and formatting
2426 information if you do.
2432 LOC: Config.onoff.log_mime_hdrs
2435 The Cache can record both the request and the response MIME
2436 headers for each HTTP transaction. The headers are encoded
2437 safely and will appear as two bracketed fields at the end of
2438 the access log (for either the native or httpd-emulated log
2439 formats). To enable this logging set log_mime_hdrs to 'on'.
2444 LOC: Config.Log.useragent
2446 IFDEF: USE_USERAGENT_LOG
2448 Squid will write the User-Agent field from HTTP requests
2449 to the filename specified here. By default useragent_log
2453 NAME: referer_log referrer_log
2455 LOC: Config.Log.referer
2457 IFDEF: USE_REFERER_LOG
2459 Squid will write the Referer field from HTTP requests to the
2460 filename specified here. By default referer_log is disabled.
2461 Note that "referer" is actually a misspelling of "referrer"
2462 however the misspelt version has been accepted into the HTTP RFCs
2468 DEFAULT: @DEFAULT_PID_FILE@
2469 LOC: Config.pidFilename
2471 A filename to write the process-id to. To disable, enter "none".
2477 LOC: Config.debugOptions
2479 Logging options are set as section,level where each source file
2480 is assigned a unique section. Lower levels result in less
2481 output, Full debugging (level 9) can result in a very large
2482 log file, so be careful. The magic word "ALL" sets debugging
2483 levels for all sections. We recommend normally running with
2491 LOC: Config.onoff.log_fqdn
2493 Turn this on if you wish to log fully qualified domain names
2494 in the access.log. To do this Squid does a DNS lookup of all
2495 IP's connecting to it. This can (in some situations) increase
2496 latency, which makes your cache seem slower for interactive
2500 NAME: client_netmask
2502 LOC: Config.Addrs.client_netmask
2503 DEFAULT: 255.255.255.255
2505 A netmask for client addresses in logfiles and cachemgr output.
2506 Change this to protect the privacy of your cache clients.
2507 A netmask of 255.255.255.0 will log all IP's in that range with
2508 the last digit set to '0'.
2515 LOC: Config.Log.forward
2517 Logs the server-side requests.
2519 This is currently work in progress.
2522 NAME: strip_query_terms
2524 LOC: Config.onoff.strip_query_terms
2527 By default, Squid strips query terms from requested URLs before
2528 logging. This protects your user's privacy.
2535 LOC: Config.onoff.buffered_logs
2537 cache.log log file is written with stdio functions, and as such
2538 it can be buffered or unbuffered. By default it will be unbuffered.
2539 Buffering it can speed up the writing slightly (though you are
2540 unlikely to need to worry unless you run with tons of debugging
2541 enabled in which case performance will suffer badly anyway..).
2544 NAME: netdb_filename
2546 DEFAULT: @DEFAULT_NETDB_FILE@
2547 LOC: Config.netdbFilename
2550 A filename where Squid stores it's netdb state between restarts.
2551 To disable, enter "none".
2555 OPTIONS FOR FTP GATEWAYING
2556 -----------------------------------------------------------------------------
2562 LOC: Config.Ftp.anon_user
2564 If you want the anonymous login password to be more informative
2565 (and enable the use of picky ftp servers), set this to something
2566 reasonable for your domain, like wwwuser@somewhere.net
2568 The reason why this is domainless by default is the
2569 request can be made on the behalf of a user in any domain,
2570 depending on how the cache is used.
2571 Some ftp server also validate the email address is valid
2572 (for example perl.com).
2575 NAME: ftp_list_width
2578 LOC: Config.Ftp.list_width
2580 Sets the width of ftp listings. This should be set to fit in
2581 the width of a standard browser. Setting this too small
2582 can cut off long filenames when browsing ftp sites.
2588 LOC: Config.Ftp.passive
2590 If your firewall does not allow Squid to use passive
2591 connections, turn off this option.
2593 Use of ftp_epsv_all option requires this to be ON.
2599 LOC: Config.Ftp.epsv_all
2601 FTP Protocol extensions permit the use of a special "EPSV ALL" command.
2603 NATs may be able to put the connection on a "fast path" through the
2604 translator, as the EPRT command will never be used and therefore,
2605 translation of the data portion of the segments will never be needed.
2607 When a client only expects to do two-way FTP transfers this may be useful.
2608 If squid finds that it must do a three-way FTP transfer after issuing
2609 an EPSV ALL command, the FTP session will fail.
2611 If you have any doubts about this option do not use it.
2612 Squid will nicely attempt all other connection methods.
2614 Requires ftp_passive to be ON (default)
2617 NAME: ftp_sanitycheck
2620 LOC: Config.Ftp.sanitycheck
2622 For security and data integrity reasons Squid by default performs
2623 sanity checks of the addresses of FTP data connections ensure the
2624 data connection is to the requested server. If you need to allow
2625 FTP connections to servers using another IP address for the data
2626 connection turn this off.
2629 NAME: ftp_telnet_protocol
2632 LOC: Config.Ftp.telnet
2634 The FTP protocol is officially defined to use the telnet protocol
2635 as transport channel for the control connection. However, many
2636 implementations are broken and does not respect this aspect of
2639 If you have trouble accessing files with ASCII code 255 in the
2640 path or similar problems involving this ASCII code you can
2641 try setting this directive to off. If that helps, report to the
2642 operator of the FTP server in question that their FTP server
2643 is broken and does not follow the FTP standard.
2647 OPTIONS FOR EXTERNAL SUPPORT PROGRAMS
2648 -----------------------------------------------------------------------------
2653 DEFAULT: @DEFAULT_DISKD@
2654 LOC: Config.Program.diskd
2656 Specify the location of the diskd executable.
2657 Note this is only useful if you have compiled in
2658 diskd as one of the store io modules.
2661 NAME: unlinkd_program
2664 DEFAULT: @DEFAULT_UNLINKD@
2665 LOC: Config.Program.unlinkd
2667 Specify the location of the executable for file deletion process.
2670 NAME: pinger_program
2672 DEFAULT: @DEFAULT_PINGER@
2673 LOC: Config.pinger.program
2676 Specify the location of the executable for the pinger process.
2682 LOC: Config.pinger.enable
2685 Control whether the pinger is active at run-time.
2686 Enables turning ICMP pinger on and off with a simple squid -k reconfigure.
2691 OPTIONS FOR URL REWRITING
2692 -----------------------------------------------------------------------------
2695 NAME: url_rewrite_program redirect_program
2697 LOC: Config.Program.redirect
2700 Specify the location of the executable for the URL rewriter.
2701 Since they can perform almost any function there isn't one included.
2703 For each requested URL rewriter will receive on line with the format
2705 URL <SP> client_ip "/" fqdn <SP> user <SP> method [<SP> kvpairs]<NL>
2707 In the future, the rewriter interface will be extended with
2708 key=value pairs ("kvpairs" shown above). Rewriter programs
2709 should be prepared to receive and possibly ignore additional
2710 whitespace-separated tokens on each input line.
2712 And the rewriter may return a rewritten URL. The other components of
2713 the request line does not need to be returned (ignored if they are).
2715 The rewriter can also indicate that a client-side redirect should
2716 be performed to the new URL. This is done by prefixing the returned
2717 URL with "301:" (moved permanently) or 302: (moved temporarily).
2719 By default, a URL rewriter is not used.
2722 NAME: url_rewrite_children redirect_children
2725 LOC: Config.redirectChildren
2727 The number of redirector processes to spawn. If you start
2728 too few Squid will have to wait for them to process a backlog of
2729 URLs, slowing it down. If you start too many they will use RAM
2730 and other system resources.
2733 NAME: url_rewrite_concurrency redirect_concurrency
2736 LOC: Config.redirectConcurrency
2738 The number of requests each redirector helper can handle in
2739 parallel. Defaults to 0 which indicates the redirector
2740 is a old-style single threaded redirector.
2743 NAME: url_rewrite_host_header redirect_rewrites_host_header
2746 LOC: Config.onoff.redir_rewrites_host
2748 By default Squid rewrites any Host: header in redirected
2749 requests. If you are running an accelerator this may
2750 not be a wanted effect of a redirector.
2752 WARNING: Entries are cached on the result of the URL rewriting
2753 process, so be careful if you have domain-virtual hosts.
2756 NAME: url_rewrite_access redirector_access
2759 LOC: Config.accessList.redirector
2761 If defined, this access list specifies which requests are
2762 sent to the redirector processes. By default all requests
2766 NAME: url_rewrite_bypass redirector_bypass
2768 LOC: Config.onoff.redirector_bypass
2771 When this is 'on', a request will not go through the
2772 redirector if all redirectors are busy. If this is 'off'
2773 and the redirector queue grows too large, Squid will exit
2774 with a FATAL error and ask you to increase the number of
2775 redirectors. You should only enable this if the redirectors
2776 are not critical to your caching system. If you use
2777 redirectors for access control, and you enable this option,
2778 users may have access to pages they should not
2779 be allowed to request.
2783 OPTIONS FOR TUNING THE CACHE
2784 -----------------------------------------------------------------------------
2787 NAME: cache no_cache
2790 LOC: Config.accessList.noCache
2792 A list of ACL elements which, if matched and denied, cause the request to
2793 not be satisfied from the cache and the reply to not be cached.
2794 In other words, use this to force certain objects to never be cached.
2796 You must use the words 'allow' or 'deny' to indicate whether items
2797 matching the ACL should be allowed or denied into the cache.
2799 Default is to allow all to be cached.
2802 NAME: refresh_pattern
2803 TYPE: refreshpattern
2807 usage: refresh_pattern [-i] regex min percent max [options]
2809 By default, regular expressions are CASE-SENSITIVE. To make
2810 them case-insensitive, use the -i option.
2812 'Min' is the time (in minutes) an object without an explicit
2813 expiry time should be considered fresh. The recommended
2814 value is 0, any higher values may cause dynamic applications
2815 to be erroneously cached unless the application designer
2816 has taken the appropriate actions.
2818 'Percent' is a percentage of the objects age (time since last
2819 modification age) an object without explicit expiry time
2820 will be considered fresh.
2822 'Max' is an upper limit on how long objects without an explicit
2823 expiry time will be considered fresh.
2825 options: override-expire
2835 override-expire enforces min age even if the server
2836 sent an explicit expiry time (e.g., with the
2837 Expires: header or Cache-Control: max-age). Doing this
2838 VIOLATES the HTTP standard. Enabling this feature
2839 could make you liable for problems which it causes.
2841 override-lastmod enforces min age even on objects
2842 that were modified recently.
2844 reload-into-ims changes client no-cache or ``reload''
2845 to If-Modified-Since requests. Doing this VIOLATES the
2846 HTTP standard. Enabling this feature could make you
2847 liable for problems which it causes.
2849 ignore-reload ignores a client no-cache or ``reload''
2850 header. Doing this VIOLATES the HTTP standard. Enabling
2851 this feature could make you liable for problems which
2854 ignore-no-cache ignores any ``Pragma: no-cache'' and
2855 ``Cache-control: no-cache'' headers received from a server.
2856 The HTTP RFC never allows the use of this (Pragma) header
2857 from a server, only a client, though plenty of servers
2860 ignore-no-store ignores any ``Cache-control: no-store''
2861 headers received from a server. Doing this VIOLATES
2862 the HTTP standard. Enabling this feature could make you
2863 liable for problems which it causes.
2865 ignore-private ignores any ``Cache-control: private''
2866 headers received from a server. Doing this VIOLATES
2867 the HTTP standard. Enabling this feature could make you
2868 liable for problems which it causes.
2870 ignore-auth caches responses to requests with authorization,
2871 as if the originserver had sent ``Cache-control: public''
2872 in the response header. Doing this VIOLATES the HTTP standard.
2873 Enabling this feature could make you liable for problems which
2876 refresh-ims causes squid to contact the origin server
2877 when a client issues an If-Modified-Since request. This
2878 ensures that the client will receive an updated version
2879 if one is available.
2881 Basically a cached object is:
2883 FRESH if expires < now, else STALE
2885 FRESH if lm-factor < percent, else STALE
2889 The refresh_pattern lines are checked in the order listed here.
2890 The first entry which matches is used. If none of the entries
2891 match the default will be used.
2893 Note, you must uncomment all the default lines if you want
2894 to change one. The default setting is only active if none is
2899 refresh_pattern ^ftp: 1440 20% 10080
2900 refresh_pattern ^gopher: 1440 0% 1440
2901 refresh_pattern -i (/cgi-bin/|\?) 0 0% 0
2902 refresh_pattern . 0 20% 4320
2906 NAME: quick_abort_min
2910 LOC: Config.quickAbort.min
2913 NAME: quick_abort_max
2917 LOC: Config.quickAbort.max
2920 NAME: quick_abort_pct
2924 LOC: Config.quickAbort.pct
2926 The cache by default continues downloading aborted requests
2927 which are almost completed (less than 16 KB remaining). This
2928 may be undesirable on slow (e.g. SLIP) links and/or very busy
2929 caches. Impatient users may tie up file descriptors and
2930 bandwidth by repeatedly requesting and immediately aborting
2933 When the user aborts a request, Squid will check the
2934 quick_abort values to the amount of data transfered until
2937 If the transfer has less than 'quick_abort_min' KB remaining,
2938 it will finish the retrieval.
2940 If the transfer has more than 'quick_abort_max' KB remaining,
2941 it will abort the retrieval.
2943 If more than 'quick_abort_pct' of the transfer has completed,
2944 it will finish the retrieval.
2946 If you do not want any retrieval to continue after the client
2947 has aborted, set both 'quick_abort_min' and 'quick_abort_max'
2950 If you want retrievals to always continue if they are being
2951 cached set 'quick_abort_min' to '-1 KB'.
2954 NAME: read_ahead_gap
2955 COMMENT: buffer-size
2957 LOC: Config.readAheadGap
2960 The amount of data the cache will buffer ahead of what has been
2961 sent to the client when retrieving an object from another server.
2965 IFDEF: HTTP_VIOLATIONS
2968 LOC: Config.negativeTtl
2971 Set the Default Time-to-Live (TTL) for failed requests.
2972 Certain types of failures (such as "connection refused" and
2973 "404 Not Found") are able to be negatively-cached for a short time.
2974 Modern web servers should provide Expires: header, however if they
2975 do not this can provide a minimum TTL.
2976 The default is not to cache errors with unknown expiry details.
2978 Note that this is different from negative caching of DNS lookups.
2980 WARNING: Doing this VIOLATES the HTTP standard. Enabling
2981 this feature could make you liable for problems which it
2985 NAME: positive_dns_ttl
2988 LOC: Config.positiveDnsTtl
2991 Upper limit on how long Squid will cache positive DNS responses.
2992 Default is 6 hours (360 minutes). This directive must be set
2993 larger than negative_dns_ttl.
2996 NAME: negative_dns_ttl
2999 LOC: Config.negativeDnsTtl
3002 Time-to-Live (TTL) for negative caching of failed DNS lookups.
3003 This also sets the lower cache limit on positive lookups.
3004 Minimum value is 1 second, and it is not recommendable to go
3005 much below 10 seconds.
3008 NAME: range_offset_limit
3011 LOC: Config.rangeOffsetLimit
3014 Sets a upper limit on how far into the the file a Range request
3015 may be to cause Squid to prefetch the whole file. If beyond this
3016 limit Squid forwards the Range request as it is and the result
3019 This is to stop a far ahead range request (lets say start at 17MB)
3020 from making Squid fetch the whole object up to that point before
3021 sending anything to the client.
3023 A value of -1 causes Squid to always fetch the object from the
3024 beginning so it may cache the result. (2.0 style)
3026 A value of 0 causes Squid to never fetch more than the
3027 client requested. (default)
3030 NAME: minimum_expiry_time
3033 LOC: Config.minimum_expiry_time
3036 The minimum caching time according to (Expires - Date)
3037 Headers Squid honors if the object can't be revalidated
3038 defaults to 60 seconds. In reverse proxy enorinments it
3039 might be desirable to honor shorter object lifetimes. It
3040 is most likely better to make your server return a
3041 meaningful Last-Modified header however. In ESI environments
3042 where page fragments often have short lifetimes, this will
3043 often be best set to 0.
3046 NAME: store_avg_object_size
3050 LOC: Config.Store.avgObjectSize
3052 Average object size, used to estimate number of objects your
3053 cache can hold. The default is 13 KB.
3056 NAME: store_objects_per_bucket
3059 LOC: Config.Store.objectsPerBucket
3061 Target number of objects per bucket in the store hash table.
3062 Lowering this value increases the total number of buckets and
3063 also the storage maintenance rate. The default is 20.
3068 -----------------------------------------------------------------------------
3071 NAME: request_header_max_size
3075 LOC: Config.maxRequestHeaderSize
3077 This specifies the maximum size for HTTP headers in a request.
3078 Request headers are usually relatively small (about 512 bytes).
3079 Placing a limit on the request header size will catch certain
3080 bugs (for example with persistent connections) and possibly
3081 buffer-overflow or denial-of-service attacks.
3084 NAME: reply_header_max_size
3088 LOC: Config.maxReplyHeaderSize
3090 This specifies the maximum size for HTTP headers in a reply.
3091 Reply headers are usually relatively small (about 512 bytes).
3092 Placing a limit on the reply header size will catch certain
3093 bugs (for example with persistent connections) and possibly
3094 buffer-overflow or denial-of-service attacks.
3097 NAME: request_body_max_size
3101 LOC: Config.maxRequestBodySize
3103 This specifies the maximum size for an HTTP request body.
3104 In other words, the maximum size of a PUT/POST request.
3105 A user who attempts to send a request with a body larger
3106 than this limit receives an "Invalid Request" error message.
3107 If you set this parameter to a zero (the default), there will
3108 be no limit imposed.
3114 LOC: Config.accessList.brokenPosts
3116 A list of ACL elements which, if matched, causes Squid to send
3117 an extra CRLF pair after the body of a PUT/POST request.
3119 Some HTTP servers has broken implementations of PUT/POST,
3120 and rely on an extra CRLF pair sent by some WWW clients.
3122 Quote from RFC2616 section 4.1 on this matter:
3124 Note: certain buggy HTTP/1.0 client implementations generate an
3125 extra CRLF's after a POST request. To restate what is explicitly
3126 forbidden by the BNF, an HTTP/1.1 client must not preface or follow
3127 a request with an extra CRLF.
3130 acl buggy_server url_regex ^http://....
3131 broken_posts allow buggy_server
3135 IFDEF: HTTP_VIOLATIONS
3139 LOC: Config.onoff.via
3141 If set (default), Squid will include a Via header in requests and
3142 replies as required by RFC2616.
3148 LOC: Config.onoff.ie_refresh
3151 Microsoft Internet Explorer up until version 5.5 Service
3152 Pack 1 has an issue with transparent proxies, wherein it
3153 is impossible to force a refresh. Turning this on provides
3154 a partial fix to the problem, by causing all IMS-REFRESH
3155 requests from older IE versions to check the origin server
3156 for fresh content. This reduces hit ratio by some amount
3157 (~10% in my experience), but allows users to actually get
3158 fresh content when they want it. Note because Squid
3159 cannot tell if the user is using 5.5 or 5.5SP1, the behavior
3160 of 5.5 is unchanged from old versions of Squid (i.e. a
3161 forced refresh is impossible). Newer versions of IE will,
3162 hopefully, continue to have the new behavior and will be
3163 handled based on that assumption. This option defaults to
3164 the old Squid behavior, which is better for hit ratios but
3165 worse for clients using IE, if they need to be able to
3166 force fresh content.
3169 NAME: vary_ignore_expire
3172 LOC: Config.onoff.vary_ignore_expire
3175 Many HTTP servers supporting Vary gives such objects
3176 immediate expiry time with no cache-control header
3177 when requested by a HTTP/1.0 client. This option
3178 enables Squid to ignore such expiry times until
3179 HTTP/1.1 is fully implemented.
3180 WARNING: This may eventually cause some varying
3181 objects not intended for caching to get cached.
3184 NAME: request_entities
3186 LOC: Config.onoff.request_entities
3189 Squid defaults to deny GET and HEAD requests with request entities,
3190 as the meaning of such requests are undefined in the HTTP standard
3191 even if not explicitly forbidden.
3193 Set this directive to on if you have clients which insists
3194 on sending request entities in GET or HEAD requests. But be warned
3195 that there is server software (both proxies and web servers) which
3196 can fail to properly process this kind of request which may make you
3197 vulnerable to cache pollution attacks if enabled.
3200 NAME: request_header_access
3201 IFDEF: HTTP_VIOLATIONS
3202 TYPE: http_header_access[]
3203 LOC: Config.request_header_access
3206 Usage: request_header_access header_name allow|deny [!]aclname ...
3208 WARNING: Doing this VIOLATES the HTTP standard. Enabling
3209 this feature could make you liable for problems which it
3212 This option replaces the old 'anonymize_headers' and the
3213 older 'http_anonymizer' option with something that is much
3214 more configurable. This new method creates a list of ACLs
3215 for each header, allowing you very fine-tuned header
3218 This option only applies to request headers, i.e., from the
3219 client to the server.
3221 You can only specify known headers for the header name.
3222 Other headers are reclassified as 'Other'. You can also
3223 refer to all the headers with 'All'.
3225 For example, to achieve the same behavior as the old
3226 'http_anonymizer standard' option, you should use:
3228 request_header_access From deny all
3229 request_header_access Referer deny all
3230 request_header_access Server deny all
3231 request_header_access User-Agent deny all
3232 request_header_access WWW-Authenticate deny all
3233 request_header_access Link deny all
3235 Or, to reproduce the old 'http_anonymizer paranoid' feature
3238 request_header_access Allow allow all
3239 request_header_access Authorization allow all
3240 request_header_access WWW-Authenticate allow all
3241 request_header_access Proxy-Authorization allow all
3242 request_header_access Proxy-Authenticate allow all
3243 request_header_access Cache-Control allow all
3244 request_header_access Content-Encoding allow all
3245 request_header_access Content-Length allow all
3246 request_header_access Content-Type allow all
3247 request_header_access Date allow all
3248 request_header_access Expires allow all
3249 request_header_access Host allow all
3250 request_header_access If-Modified-Since allow all
3251 request_header_access Last-Modified allow all
3252 request_header_access Location allow all
3253 request_header_access Pragma allow all
3254 request_header_access Accept allow all
3255 request_header_access Accept-Charset allow all
3256 request_header_access Accept-Encoding allow all
3257 request_header_access Accept-Language allow all
3258 request_header_access Content-Language allow all
3259 request_header_access Mime-Version allow all
3260 request_header_access Retry-After allow all
3261 request_header_access Title allow all
3262 request_header_access Connection allow all
3263 request_header_access Proxy-Connection allow all
3264 request_header_access All deny all
3266 although many of those are HTTP reply headers, and so should be
3267 controlled with the reply_header_access directive.
3269 By default, all headers are allowed (no anonymizing is
3273 NAME: reply_header_access
3274 IFDEF: HTTP_VIOLATIONS
3275 TYPE: http_header_access[]
3276 LOC: Config.reply_header_access
3279 Usage: reply_header_access header_name allow|deny [!]aclname ...
3281 WARNING: Doing this VIOLATES the HTTP standard. Enabling
3282 this feature could make you liable for problems which it
3285 This option only applies to reply headers, i.e., from the
3286 server to the client.
3288 This is the same as request_header_access, but in the other
3291 This option replaces the old 'anonymize_headers' and the
3292 older 'http_anonymizer' option with something that is much
3293 more configurable. This new method creates a list of ACLs
3294 for each header, allowing you very fine-tuned header
3297 You can only specify known headers for the header name.
3298 Other headers are reclassified as 'Other'. You can also
3299 refer to all the headers with 'All'.
3301 For example, to achieve the same behavior as the old
3302 'http_anonymizer standard' option, you should use:
3304 reply_header_access From deny all
3305 reply_header_access Referer deny all
3306 reply_header_access Server deny all
3307 reply_header_access User-Agent deny all
3308 reply_header_access WWW-Authenticate deny all
3309 reply_header_access Link deny all
3311 Or, to reproduce the old 'http_anonymizer paranoid' feature
3314 reply_header_access Allow allow all
3315 reply_header_access Authorization allow all
3316 reply_header_access WWW-Authenticate allow all
3317 reply_header_access Proxy-Authorization allow all
3318 reply_header_access Proxy-Authenticate allow all
3319 reply_header_access Cache-Control allow all
3320 reply_header_access Content-Encoding allow all
3321 reply_header_access Content-Length allow all
3322 reply_header_access Content-Type allow all
3323 reply_header_access Date allow all
3324 reply_header_access Expires allow all
3325 reply_header_access Host allow all
3326 reply_header_access If-Modified-Since allow all
3327 reply_header_access Last-Modified allow all
3328 reply_header_access Location allow all
3329 reply_header_access Pragma allow all
3330 reply_header_access Accept allow all
3331 reply_header_access Accept-Charset allow all
3332 reply_header_access Accept-Encoding allow all
3333 reply_header_access Accept-Language allow all
3334 reply_header_access Content-Language allow all
3335 reply_header_access Mime-Version allow all
3336 reply_header_access Retry-After allow all
3337 reply_header_access Title allow all
3338 reply_header_access Connection allow all
3339 reply_header_access Proxy-Connection allow all
3340 reply_header_access All deny all
3342 although the HTTP request headers won't be usefully controlled
3343 by this directive -- see request_header_access for details.
3345 By default, all headers are allowed (no anonymizing is
3349 NAME: header_replace
3350 IFDEF: HTTP_VIOLATIONS
3351 TYPE: http_header_replace[]
3352 LOC: Config.request_header_access
3355 Usage: header_replace header_name message
3356 Example: header_replace User-Agent Nutscrape/1.0 (CP/M; 8-bit)
3358 This option allows you to change the contents of headers
3359 denied with header_access above, by replacing them with
3360 some fixed string. This replaces the old fake_user_agent
3363 This only applies to request headers, not reply headers.
3365 By default, headers are removed if denied.
3368 NAME: relaxed_header_parser
3369 COMMENT: on|off|warn
3371 LOC: Config.onoff.relaxed_header_parser
3374 In the default "on" setting Squid accepts certain forms
3375 of non-compliant HTTP messages where it is unambiguous
3376 what the sending application intended even if the message
3377 is not correctly formatted. The messages is then normalized
3378 to the correct form when forwarded by Squid.
3380 If set to "warn" then a warning will be emitted in cache.log
3381 each time such HTTP error is encountered.
3383 If set to "off" then such HTTP errors will cause the request
3384 or response to be rejected.
3389 -----------------------------------------------------------------------------
3392 NAME: forward_timeout
3395 LOC: Config.Timeout.forward
3398 This parameter specifies how long Squid should at most attempt in
3399 finding a forwarding path for the request before giving up.
3402 NAME: connect_timeout
3405 LOC: Config.Timeout.connect
3408 This parameter specifies how long to wait for the TCP connect to
3409 the requested server or peer to complete before Squid should
3410 attempt to find another path where to forward the request.
3413 NAME: peer_connect_timeout
3416 LOC: Config.Timeout.peer_connect
3419 This parameter specifies how long to wait for a pending TCP
3420 connection to a peer cache. The default is 30 seconds. You
3421 may also set different timeout values for individual neighbors
3422 with the 'connect-timeout' option on a 'cache_peer' line.
3428 LOC: Config.Timeout.read
3431 The read_timeout is applied on server-side connections. After
3432 each successful read(), the timeout will be extended by this
3433 amount. If no data is read again after this amount of time,
3434 the request is aborted and logged with ERR_READ_TIMEOUT. The
3435 default is 15 minutes.
3438 NAME: request_timeout
3440 LOC: Config.Timeout.request
3443 How long to wait for an HTTP request after initial
3444 connection establishment.
3447 NAME: persistent_request_timeout
3449 LOC: Config.Timeout.persistent_request
3452 How long to wait for the next HTTP request on a persistent
3453 connection after the previous request completes.
3456 NAME: client_lifetime
3459 LOC: Config.Timeout.lifetime
3462 The maximum amount of time a client (browser) is allowed to
3463 remain connected to the cache process. This protects the Cache
3464 from having a lot of sockets (and hence file descriptors) tied up
3465 in a CLOSE_WAIT state from remote clients that go away without
3466 properly shutting down (either because of a network failure or
3467 because of a poor client implementation). The default is one
3470 NOTE: The default value is intended to be much larger than any
3471 client would ever need to be connected to your cache. You
3472 should probably change client_lifetime only as a last resort.
3473 If you seem to have many client connections tying up
3474 filedescriptors, we recommend first tuning the read_timeout,
3475 request_timeout, persistent_request_timeout and quick_abort values.
3478 NAME: half_closed_clients
3480 LOC: Config.onoff.half_closed_clients
3483 Some clients may shutdown the sending side of their TCP
3484 connections, while leaving their receiving sides open. Sometimes,
3485 Squid can not tell the difference between a half-closed and a
3486 fully-closed TCP connection. By default, half-closed client
3487 connections are kept open until a read(2) or write(2) on the
3488 socket returns an error. Change this option to 'off' and Squid
3489 will immediately close client connections when read(2) returns
3490 "no more data to read."
3495 LOC: Config.Timeout.pconn
3498 Timeout for idle persistent connections to servers and other
3505 LOC: Config.Timeout.ident
3508 Maximum time to wait for IDENT lookups to complete.
3510 If this is too high, and you enabled IDENT lookups from untrusted
3511 users, you might be susceptible to denial-of-service by having
3512 many ident requests going at once.
3515 NAME: shutdown_lifetime
3518 LOC: Config.shutdownLifetime
3521 When SIGTERM or SIGHUP is received, the cache is put into
3522 "shutdown pending" mode until all active sockets are closed.
3523 This value is the lifetime to set for all open descriptors
3524 during shutdown mode. Any active clients after this many
3525 seconds will receive a 'timeout' message.
3529 ADMINISTRATIVE PARAMETERS
3530 -----------------------------------------------------------------------------
3536 LOC: Config.adminEmail
3538 Email-address of local cache manager who will receive
3539 mail if the cache dies. The default is "webmaster."
3545 LOC: Config.EmailFrom
3547 From: email-address for mail sent when the cache dies.
3548 The default is to use 'appname@unique_hostname'.
3549 Default appname value is "squid", can be changed into
3550 src/globals.h before building squid.
3556 LOC: Config.EmailProgram
3558 Email program used to send mail if the cache dies.
3559 The default is "mail". The specified program must comply
3560 with the standard Unix mail syntax:
3561 mail-program recipient < mailfile
3563 Optional command line options can be specified.
3566 NAME: cache_effective_user
3568 DEFAULT: @DEFAULT_CACHE_EFFECTIVE_USER@
3569 LOC: Config.effectiveUser
3571 If you start Squid as root, it will change its effective/real
3572 UID/GID to the user specified below. The default is to change
3573 to UID of @DEFAULT_CACHE_EFFECTIVE_USER@.
3574 see also; cache_effective_group
3577 NAME: cache_effective_group
3580 LOC: Config.effectiveGroup
3582 Squid sets the GID to the effective user's default group ID
3583 (taken from the password file) and supplementary group list
3584 from the groups membership.
3586 If you want Squid to run with a specific GID regardless of
3587 the group memberships of the effective user then set this
3588 to the group (or GID) you want Squid to run as. When set
3589 all other group privileges of the effective user are ignored
3590 and only this GID is effective. If Squid is not started as
3591 root the user starting Squid MUST be member of the specified
3594 This option is not recommended by the Squid Team.
3595 Our preference is for administrators to configure a secure
3596 user account for squid with UID/GID matching system policies.
3599 NAME: httpd_suppress_version_string
3603 LOC: Config.onoff.httpd_suppress_version_string
3605 Suppress Squid version string info in HTTP headers and HTML error pages.
3608 NAME: visible_hostname
3610 LOC: Config.visibleHostname
3613 If you want to present a special hostname in error messages, etc,
3614 define this. Otherwise, the return value of gethostname()
3615 will be used. If you have multiple caches in a cluster and
3616 get errors about IP-forwarding you must set them to have individual
3617 names with this setting.
3620 NAME: unique_hostname
3622 LOC: Config.uniqueHostname
3625 If you want to have multiple machines with the same
3626 'visible_hostname' you must give each machine a different
3627 'unique_hostname' so forwarding loops can be detected.
3630 NAME: hostname_aliases
3632 LOC: Config.hostnameAliases
3635 A list of other DNS names your cache has.
3643 Minimum umask which should be enforced while the proxy
3644 is running, in addition to the umask set at startup.
3646 For a traditional octal representation of umasks, start
3651 OPTIONS FOR THE CACHE REGISTRATION SERVICE
3652 -----------------------------------------------------------------------------
3654 This section contains parameters for the (optional) cache
3655 announcement service. This service is provided to help
3656 cache administrators locate one another in order to join or
3657 create cache hierarchies.
3659 An 'announcement' message is sent (via UDP) to the registration
3660 service by Squid. By default, the announcement message is NOT
3661 SENT unless you enable it with 'announce_period' below.
3663 The announcement message includes your hostname, plus the
3664 following information from this configuration file:
3670 All current information is processed regularly and made
3671 available on the Web at http://www.ircache.net/Cache/Tracker/.
3674 NAME: announce_period
3676 LOC: Config.Announce.period
3679 This is how frequently to send cache announcements. The
3680 default is `0' which disables sending the announcement
3683 To enable announcing your cache, just uncomment the line
3687 #To enable announcing your cache, just uncomment the line below.
3688 #announce_period 1 day
3694 DEFAULT: tracker.ircache.net
3695 LOC: Config.Announce.host
3701 LOC: Config.Announce.file
3707 LOC: Config.Announce.port
3709 announce_host and announce_port set the hostname and port
3710 number where the registration message will be sent.
3712 Hostname will default to 'tracker.ircache.net' and port will
3713 default default to 3131. If the 'filename' argument is given,
3714 the contents of that file will be included in the announce
3719 HTTPD-ACCELERATOR OPTIONS
3720 -----------------------------------------------------------------------------
3723 NAME: httpd_accel_surrogate_id
3724 IFDEF: USE_SQUID_ESI
3726 LOC: Config.Accel.surrogate_id
3729 Surrogates (http://www.esi.org/architecture_spec_1.0.html)
3730 need an identification token to allow control targeting. Because
3731 a farm of surrogates may all perform the same tasks, they may share
3732 an identification token.
3735 NAME: http_accel_surrogate_remote
3736 IFDEF: USE_SQUID_ESI
3740 LOC: Config.onoff.surrogate_is_remote
3742 Remote surrogates (such as those in a CDN) honour Surrogate-Control: no-store-remote.
3743 Set this to on to have squid behave as a remote surrogate.
3747 IFDEF: USE_SQUID_ESI
3748 COMMENT: libxml2|expat|custom
3750 LOC: ESIParser::Type
3753 ESI markup is not strictly XML compatible. The custom ESI parser
3754 will give higher performance, but cannot handle non ASCII character
3759 DELAY POOL PARAMETERS
3760 -----------------------------------------------------------------------------
3764 TYPE: delay_pool_count
3769 This represents the number of delay pools to be used. For example,
3770 if you have one class 2 delay pool and one class 3 delays pool, you
3771 have a total of 2 delay pools.
3775 TYPE: delay_pool_class
3780 This defines the class of each delay pool. There must be exactly one
3781 delay_class line for each delay pool. For example, to define two
3782 delay pools, one of class 2 and one of class 3, the settings above
3786 delay_pools 4 # 4 delay pools
3787 delay_class 1 2 # pool 1 is a class 2 pool
3788 delay_class 2 3 # pool 2 is a class 3 pool
3789 delay_class 3 4 # pool 3 is a class 4 pool
3790 delay_class 4 5 # pool 4 is a class 5 pool
3792 The delay pool classes are:
3794 class 1 Everything is limited by a single aggregate
3797 class 2 Everything is limited by a single aggregate
3798 bucket as well as an "individual" bucket chosen
3799 from bits 25 through 32 of the IP address.
3801 class 3 Everything is limited by a single aggregate
3802 bucket as well as a "network" bucket chosen
3803 from bits 17 through 24 of the IP address and a
3804 "individual" bucket chosen from bits 17 through
3805 32 of the IP address.
3807 class 4 Everything in a class 3 delay pool, with an
3808 additional limit on a per user basis. This
3809 only takes effect if the username is established
3810 in advance - by forcing authentication in your
3813 class 5 Requests are grouped according their tag (see
3814 external_acl's tag= reply).
3816 NOTE: If an IP address is a.b.c.d
3817 -> bits 25 through 32 are "d"
3818 -> bits 17 through 24 are "c"
3819 -> bits 17 through 32 are "c * 256 + d"
3823 TYPE: delay_pool_access
3828 This is used to determine which delay pool a request falls into.
3830 delay_access is sorted per pool and the matching starts with pool 1,
3831 then pool 2, ..., and finally pool N. The first delay pool where the
3832 request is allowed is selected for the request. If it does not allow
3833 the request to any pool then the request is not delayed (default).
3835 For example, if you want some_big_clients in delay
3836 pool 1 and lotsa_little_clients in delay pool 2:
3839 delay_access 1 allow some_big_clients
3840 delay_access 1 deny all
3841 delay_access 2 allow lotsa_little_clients
3842 delay_access 2 deny all
3843 delay_access 3 allow authenticated_clients
3846 NAME: delay_parameters
3847 TYPE: delay_pool_rates
3852 This defines the parameters for a delay pool. Each delay pool has
3853 a number of "buckets" associated with it, as explained in the
3854 description of delay_class. For a class 1 delay pool, the syntax is:
3856 delay_parameters pool aggregate
3858 For a class 2 delay pool:
3860 delay_parameters pool aggregate individual
3862 For a class 3 delay pool:
3864 delay_parameters pool aggregate network individual
3866 For a class 4 delay pool:
3868 delay_parameters pool aggregate network individual user
3870 For a class 5 delay pool:
3872 delay_parameters pool tag
3874 The variables here are:
3876 pool a pool number - ie, a number between 1 and the
3877 number specified in delay_pools as used in
3880 aggregate the "delay parameters" for the aggregate bucket
3883 individual the "delay parameters" for the individual
3884 buckets (class 2, 3).
3886 network the "delay parameters" for the network buckets
3889 user the delay parameters for the user buckets
3892 tag the delay parameters for the tag buckets
3895 A pair of delay parameters is written restore/maximum, where restore is
3896 the number of bytes (not bits - modem and network speeds are usually
3897 quoted in bits) per second placed into the bucket, and maximum is the
3898 maximum number of bytes which can be in the bucket at any time.
3900 For example, if delay pool number 1 is a class 2 delay pool as in the
3901 above example, and is being used to strictly limit each host to 64kbps
3902 (plus overheads), with no overall limit, the line is:
3904 delay_parameters 1 -1/-1 8000/8000
3906 Note that the figure -1 is used to represent "unlimited".
3908 And, if delay pool number 2 is a class 3 delay pool as in the above
3909 example, and you want to limit it to a total of 256kbps (strict limit)
3910 with each 8-bit network permitted 64kbps (strict limit) and each
3911 individual host permitted 4800bps with a bucket maximum size of 64kb
3912 to permit a decent web page to be downloaded at a decent speed
3913 (if the network is not being limited due to overuse) but slow down
3914 large downloads more significantly:
3916 delay_parameters 2 32000/32000 8000/8000 600/8000
3918 There must be one delay_parameters line for each delay pool.
3920 Finally, for a class 4 delay pool as in the example - each user will
3921 be limited to 128Kb no matter how many workstations they are logged into.:
3923 delay_parameters 4 32000/32000 8000/8000 600/64000 16000/16000
3926 NAME: delay_initial_bucket_level
3927 COMMENT: (percent, 0-100)
3931 LOC: Config.Delay.initial
3933 The initial bucket percentage is used to determine how much is put
3934 in each bucket when squid starts, is reconfigured, or first notices
3935 a host accessing it (in class 2 and class 3, individual hosts and
3936 networks only have buckets associated with them once they have been
3941 WCCPv1 AND WCCPv2 CONFIGURATION OPTIONS
3942 -----------------------------------------------------------------------------
3947 LOC: Config.Wccp.router
3952 TYPE: IPAddress_list
3953 LOC: Config.Wccp2.router
3957 Use this option to define your WCCP ``home'' router for
3960 wccp_router supports a single WCCP(v1) router
3962 wccp2_router supports multiple WCCPv2 routers
3964 only one of the two may be used at the same time and defines
3965 which version of WCCP to use.
3970 LOC: Config.Wccp.version
3974 This directive is only relevant if you need to set up WCCP(v1)
3975 to some very old and end-of-life Cisco routers. In all other
3976 setups it must be left unset or at the default setting.
3977 It defines an internal version in the WCCP(v1) protocol,
3978 with version 4 being the officially documented protocol.
3980 According to some users, Cisco IOS 11.2 and earlier only
3981 support WCCP version 3. If you're using that or an earlier
3982 version of IOS, you may need to change this value to 3, otherwise
3983 do not specify this parameter.
3986 NAME: wccp2_rebuild_wait
3988 LOC: Config.Wccp2.rebuildwait
3992 If this is enabled Squid will wait for the cache dir rebuild to finish
3993 before sending the first wccp2 HereIAm packet
3996 NAME: wccp2_forwarding_method
3998 LOC: Config.Wccp2.forwarding_method
4002 WCCP2 allows the setting of forwarding methods between the
4003 router/switch and the cache. Valid values are as follows:
4005 1 - GRE encapsulation (forward the packet in a GRE/WCCP tunnel)
4006 2 - L2 redirect (forward the packet using Layer 2/MAC rewriting)
4008 Currently (as of IOS 12.4) cisco routers only support GRE.
4009 Cisco switches only support the L2 redirect assignment method.
4012 NAME: wccp2_return_method
4014 LOC: Config.Wccp2.return_method
4018 WCCP2 allows the setting of return methods between the
4019 router/switch and the cache for packets that the cache
4020 decides not to handle. Valid values are as follows:
4022 1 - GRE encapsulation (forward the packet in a GRE/WCCP tunnel)
4023 2 - L2 redirect (forward the packet using Layer 2/MAC rewriting)
4025 Currently (as of IOS 12.4) cisco routers only support GRE.
4026 Cisco switches only support the L2 redirect assignment.
4028 If the "ip wccp redirect exclude in" command has been
4029 enabled on the cache interface, then it is still safe for
4030 the proxy server to use a l2 redirect method even if this
4031 option is set to GRE.
4034 NAME: wccp2_assignment_method
4036 LOC: Config.Wccp2.assignment_method
4040 WCCP2 allows the setting of methods to assign the WCCP hash
4041 Valid values are as follows:
4046 As a general rule, cisco routers support the hash assignment method
4047 and cisco switches support the mask assignment method.
4052 LOC: Config.Wccp2.info
4054 DEFAULT_IF_NONE: standard 0
4057 WCCP2 allows for multiple traffic services. There are two
4058 types: "standard" and "dynamic". The standard type defines
4059 one service id - http (id 0). The dynamic service ids can be from
4060 51 to 255 inclusive. In order to use a dynamic service id
4061 one must define the type of traffic to be redirected; this is done
4062 using the wccp2_service_info option.
4064 The "standard" type does not require a wccp2_service_info option,
4065 just specifying the service id will suffice.
4067 MD5 service authentication can be enabled by adding
4068 "password=<password>" to the end of this service declaration.
4072 wccp2_service standard 0 # for the 'web-cache' standard service
4073 wccp2_service dynamic 80 # a dynamic service type which will be
4074 # fleshed out with subsequent options.
4075 wccp2_service standard 0 password=foo
4079 NAME: wccp2_service_info
4080 TYPE: wccp2_service_info
4081 LOC: Config.Wccp2.info
4085 Dynamic WCCPv2 services require further information to define the
4086 traffic you wish to have diverted.
4090 wccp2_service_info <id> protocol=<protocol> flags=<flag>,<flag>..
4091 priority=<priority> ports=<port>,<port>..
4093 The relevant WCCPv2 flags:
4094 + src_ip_hash, dst_ip_hash
4095 + source_port_hash, dest_port_hash
4096 + src_ip_alt_hash, dst_ip_alt_hash
4097 + src_port_alt_hash, dst_port_alt_hash
4100 The port list can be one to eight entries.
4104 wccp2_service_info 80 protocol=tcp flags=src_ip_hash,ports_source
4105 priority=240 ports=80
4107 Note: the service id must have been defined by a previous
4108 'wccp2_service dynamic <id>' entry.
4113 LOC: Config.Wccp2.weight
4117 Each cache server gets assigned a set of the destination
4118 hash proportional to their weight.
4123 LOC: Config.Wccp.address
4129 LOC: Config.Wccp2.address
4133 Use this option if you require WCCP to use a specific
4136 The default behavior is to not bind to any specific address.
4140 PERSISTENT CONNECTION HANDLING
4141 -----------------------------------------------------------------------------
4143 Also see "pconn_timeout" in the TIMEOUTS section
4146 NAME: client_persistent_connections
4148 LOC: Config.onoff.client_pconns
4152 NAME: server_persistent_connections
4154 LOC: Config.onoff.server_pconns
4157 Persistent connection support for clients and servers. By
4158 default, Squid uses persistent connections (when allowed)
4159 with its clients and servers. You can use these options to
4160 disable persistent connections with clients and/or servers.
4163 NAME: persistent_connection_after_error
4165 LOC: Config.onoff.error_pconns
4168 With this directive the use of persistent connections after
4169 HTTP errors can be disabled. Useful if you have clients
4170 who fail to handle errors on persistent connections proper.
4173 NAME: detect_broken_pconn
4175 LOC: Config.onoff.detect_broken_server_pconns
4178 Some servers have been found to incorrectly signal the use
4179 of HTTP/1.0 persistent connections even on replies not
4180 compatible, causing significant delays. This server problem
4181 has mostly been seen on redirects.
4183 By enabling this directive Squid attempts to detect such
4184 broken replies and automatically assume the reply is finished
4185 after 10 seconds timeout.
4189 CACHE DIGEST OPTIONS
4190 -----------------------------------------------------------------------------
4193 NAME: digest_generation
4194 IFDEF: USE_CACHE_DIGESTS
4196 LOC: Config.onoff.digest_generation
4199 This controls whether the server will generate a Cache Digest
4200 of its contents. By default, Cache Digest generation is
4201 enabled if Squid is compiled with --enable-cache-digests defined.
4204 NAME: digest_bits_per_entry
4205 IFDEF: USE_CACHE_DIGESTS
4207 LOC: Config.digest.bits_per_entry
4210 This is the number of bits of the server's Cache Digest which
4211 will be associated with the Digest entry for a given HTTP
4212 Method and URL (public key) combination. The default is 5.
4215 NAME: digest_rebuild_period
4216 IFDEF: USE_CACHE_DIGESTS
4219 LOC: Config.digest.rebuild_period
4222 This is the wait time between Cache Digest rebuilds.
4225 NAME: digest_rewrite_period
4227 IFDEF: USE_CACHE_DIGESTS
4229 LOC: Config.digest.rewrite_period
4232 This is the wait time between Cache Digest writes to
4236 NAME: digest_swapout_chunk_size
4239 IFDEF: USE_CACHE_DIGESTS
4240 LOC: Config.digest.swapout_chunk_size
4243 This is the number of bytes of the Cache Digest to write to
4244 disk at a time. It defaults to 4096 bytes (4KB), the Squid
4248 NAME: digest_rebuild_chunk_percentage
4249 COMMENT: (percent, 0-100)
4250 IFDEF: USE_CACHE_DIGESTS
4252 LOC: Config.digest.rebuild_chunk_percentage
4255 This is the percentage of the Cache Digest to be scanned at a
4256 time. By default it is set to 10% of the Cache Digest.
4261 -----------------------------------------------------------------------------
4266 LOC: Config.Port.snmp
4270 The port number where Squid listens for SNMP requests. To enable
4271 SNMP support set this to a suitable port number. Port number
4272 3401 is often used for the Squid SNMP agent. By default it's
4273 set to "0" (disabled)
4281 LOC: Config.accessList.snmp
4283 DEFAULT_IF_NONE: deny all
4286 Allowing or denying access to the SNMP port.
4288 All access to the agent is denied by default.
4291 snmp_access allow|deny [!]aclname ...
4294 snmp_access allow snmppublic localhost
4295 snmp_access deny all
4298 NAME: snmp_incoming_address
4300 LOC: Config.Addrs.snmp_incoming
4304 NAME: snmp_outgoing_address
4306 LOC: Config.Addrs.snmp_outgoing
4307 DEFAULT: 255.255.255.255
4310 Just like 'udp_incoming_address' above, but for the SNMP port.
4312 snmp_incoming_address is used for the SNMP socket receiving
4313 messages from SNMP agents.
4314 snmp_outgoing_address is used for SNMP packets returned to SNMP
4317 The default snmp_incoming_address (0.0.0.0) is to listen on all
4318 available network interfaces.
4320 If snmp_outgoing_address is set to 255.255.255.255 (the default)
4321 it will use the same socket as snmp_incoming_address. Only
4322 change this if you want to have SNMP replies sent using another
4323 address than where this Squid listens for SNMP queries.
4325 NOTE, snmp_incoming_address and snmp_outgoing_address can not have
4326 the same value since they both use port 3401.
4331 -----------------------------------------------------------------------------
4334 NAME: icp_port udp_port
4337 LOC: Config.Port.icp
4339 The port number where Squid sends and receives ICP queries to
4340 and from neighbor caches. The standard UDP port for ICP is 3130.
4341 Default is disabled (0).
4343 icp_port @DEFAULT_ICP_PORT@
4351 LOC: Config.Port.htcp
4353 The port number where Squid sends and receives HTCP queries to
4354 and from neighbor caches. To turn it on you want to set it to
4355 4827. By default it is set to "0" (disabled).
4361 NAME: log_icp_queries
4365 LOC: Config.onoff.log_udp
4367 If set, ICP queries are logged to access.log. You may wish
4368 do disable this if your ICP load is VERY high to speed things
4369 up or to simplify log analysis.
4372 NAME: udp_incoming_address
4374 LOC:Config.Addrs.udp_incoming
4377 udp_incoming_address is used for UDP packets received from other
4380 The default behavior is to not bind to any specific address.
4382 Only change this if you want to have all UDP queries received on
4383 a specific interface/address.
4385 NOTE: udp_incoming_address is used by the ICP, HTCP, and DNS
4386 modules. Altering it will affect all of them in the same manner.
4388 see also; udp_outgoing_address
4390 NOTE, udp_incoming_address and udp_outgoing_address can not
4391 have the same value since they both use the same port.
4394 NAME: udp_outgoing_address
4396 LOC: Config.Addrs.udp_outgoing
4397 DEFAULT: 255.255.255.255
4399 udp_outgoing_address is used for UDP packets sent out to other
4402 The default behavior is to not bind to any specific address.
4404 Instead it will use the same socket as udp_incoming_address.
4405 Only change this if you want to have UDP queries sent using another
4406 address than where this Squid listens for UDP queries from other
4409 NOTE: udp_outgoing_address is used by the ICP, HTCP, and DNS
4410 modules. Altering it will affect all of them in the same manner.
4412 see also; udp_incoming_address
4414 NOTE, udp_incoming_address and udp_outgoing_address can not
4415 have the same value since they both use the same port.
4422 LOC: Config.onoff.icp_hit_stale
4424 If you want to return ICP_HIT for stale cache objects, set this
4425 option to 'on'. If you have sibling relationships with caches
4426 in other administrative domains, this should be 'off'. If you only
4427 have sibling relationships with caches under your control,
4428 it is probably okay to set this to 'on'.
4429 If set to 'on', your siblings should use the option "allow-miss"
4430 on their cache_peer lines for connecting to you.
4433 NAME: minimum_direct_hops
4436 LOC: Config.minDirectHops
4438 If using the ICMP pinging stuff, do direct fetches for sites
4439 which are no more than this many hops away.
4442 NAME: minimum_direct_rtt
4445 LOC: Config.minDirectRtt
4447 If using the ICMP pinging stuff, do direct fetches for sites
4448 which are no more than this many rtt milliseconds away.
4454 LOC: Config.Netdb.low
4460 LOC: Config.Netdb.high
4462 The low and high water marks for the ICMP measurement
4463 database. These are counts, not percents. The defaults are
4464 900 and 1000. When the high water mark is reached, database
4465 entries will be deleted until the low mark is reached.
4468 NAME: netdb_ping_period
4470 LOC: Config.Netdb.period
4473 The minimum period for measuring a site. There will be at
4474 least this much delay between successive pings to the same
4475 network. The default is five minutes.
4482 LOC: Config.onoff.query_icmp
4484 If you want to ask your peers to include ICMP data in their ICP
4485 replies, enable this option.
4487 If your peer has configured Squid (during compilation) with
4488 '--enable-icmp' that peer will send ICMP pings to origin server
4489 sites of the URLs it receives. If you enable this option the
4490 ICP replies from that peer will include the ICMP data (if available).
4491 Then, when choosing a parent cache, Squid will choose the parent with
4492 the minimal RTT to the origin server. When this happens, the
4493 hierarchy field of the access.log will be
4494 "CLOSEST_PARENT_MISS". This option is off by default.
4497 NAME: test_reachability
4501 LOC: Config.onoff.test_reachability
4503 When this is 'on', ICP MISS replies will be ICP_MISS_NOFETCH
4504 instead of ICP_MISS if the target host is NOT in the ICMP
4505 database, or has a zero RTT.
4508 NAME: icp_query_timeout
4512 LOC: Config.Timeout.icp_query
4514 Normally Squid will automatically determine an optimal ICP
4515 query timeout value based on the round-trip-time of recent ICP
4516 queries. If you want to override the value determined by
4517 Squid, set this 'icp_query_timeout' to a non-zero value. This
4518 value is specified in MILLISECONDS, so, to use a 2-second
4519 timeout (the old default), you would write:
4521 icp_query_timeout 2000
4524 NAME: maximum_icp_query_timeout
4528 LOC: Config.Timeout.icp_query_max
4530 Normally the ICP query timeout is determined dynamically. But
4531 sometimes it can lead to very large values (say 5 seconds).
4532 Use this option to put an upper limit on the dynamic timeout
4533 value. Do NOT use this option to always use a fixed (instead
4534 of a dynamic) timeout value. To set a fixed timeout see the
4535 'icp_query_timeout' directive.
4538 NAME: minimum_icp_query_timeout
4542 LOC: Config.Timeout.icp_query_min
4544 Normally the ICP query timeout is determined dynamically. But
4545 sometimes it can lead to very small timeouts, even lower than
4546 the normal latency variance on your link due to traffic.
4547 Use this option to put an lower limit on the dynamic timeout
4548 value. Do NOT use this option to always use a fixed (instead
4549 of a dynamic) timeout value. To set a fixed timeout see the
4550 'icp_query_timeout' directive.
4553 NAME: background_ping_rate
4557 LOC: Config.backgroundPingRate
4559 Controls how often the ICP pings are sent to siblings that
4560 have background-ping set.
4564 MULTICAST ICP OPTIONS
4565 -----------------------------------------------------------------------------
4570 LOC: Config.mcast_group_list
4573 This tag specifies a list of multicast groups which your server
4574 should join to receive multicasted ICP queries.
4576 NOTE! Be very careful what you put here! Be sure you
4577 understand the difference between an ICP _query_ and an ICP
4578 _reply_. This option is to be set only if you want to RECEIVE
4579 multicast queries. Do NOT set this option to SEND multicast
4580 ICP (use cache_peer for that). ICP replies are always sent via
4581 unicast, so this option does not affect whether or not you will
4582 receive replies from multicast group members.
4584 You must be very careful to NOT use a multicast address which
4585 is already in use by another group of caches.
4587 If you are unsure about multicast, please read the Multicast
4588 chapter in the Squid FAQ (http://www.squid-cache.org/FAQ/).
4590 Usage: mcast_groups 239.128.16.128 224.0.1.20
4592 By default, Squid doesn't listen on any multicast groups.
4595 NAME: mcast_miss_addr
4596 IFDEF: MULTICAST_MISS_STREAM
4598 LOC: Config.mcast_miss.addr
4599 DEFAULT: 255.255.255.255
4601 If you enable this option, every "cache miss" URL will
4602 be sent out on the specified multicast address.
4604 Do not enable this option unless you are are absolutely
4605 certain you understand what you are doing.
4608 NAME: mcast_miss_ttl
4609 IFDEF: MULTICAST_MISS_STREAM
4611 LOC: Config.mcast_miss.ttl
4614 This is the time-to-live value for packets multicasted
4615 when multicasting off cache miss URLs is enabled. By
4616 default this is set to 'site scope', i.e. 16.
4619 NAME: mcast_miss_port
4620 IFDEF: MULTICAST_MISS_STREAM
4622 LOC: Config.mcast_miss.port
4625 This is the port number to be used in conjunction with
4629 NAME: mcast_miss_encode_key
4630 IFDEF: MULTICAST_MISS_STREAM
4632 LOC: Config.mcast_miss.encode_key
4633 DEFAULT: XXXXXXXXXXXXXXXX
4635 The URLs that are sent in the multicast miss stream are
4636 encrypted. This is the encryption key.
4639 NAME: mcast_icp_query_timeout
4643 LOC: Config.Timeout.mcast_icp_query
4645 For multicast peers, Squid regularly sends out ICP "probes" to
4646 count how many other peers are listening on the given multicast
4647 address. This value specifies how long Squid should wait to
4648 count all the replies. The default is 2000 msec, or 2
4653 INTERNAL ICON OPTIONS
4654 -----------------------------------------------------------------------------
4657 NAME: icon_directory
4659 LOC: Config.icons.directory
4660 DEFAULT: @DEFAULT_ICON_DIR@
4662 Where the icons are stored. These are normally kept in
4666 NAME: global_internal_static
4668 LOC: Config.onoff.global_internal_static
4671 This directive controls is Squid should intercept all requests for
4672 /squid-internal-static/ no matter which host the URL is requesting
4673 (default on setting), or if nothing special should be done for
4674 such URLs (off setting). The purpose of this directive is to make
4675 icons etc work better in complex cache hierarchies where it may
4676 not always be possible for all corners in the cache mesh to reach
4677 the server generating a directory listing.
4680 NAME: short_icon_urls
4682 LOC: Config.icons.use_short_names
4685 If this is enabled Squid will use short URLs for icons.
4686 If disabled it will revert to the old behavior of including
4687 it's own name and port in the URL.
4689 If you run a complex cache hierarchy with a mix of Squid and
4690 other proxies you may need to disable this directive.
4695 -----------------------------------------------------------------------------
4698 NAME: error_directory
4700 LOC: Config.errorDirectory
4701 DEFAULT: @DEFAULT_ERROR_DIR@
4703 If you wish to create your own versions of the default
4704 (English) error files, either to customize them to suit your
4705 language or company copy the template English files to another
4706 directory and point this tag at them.
4708 The squid developers are interested in making squid available in
4709 a wide variety of languages. If you are making translations for a
4710 langauge that Squid does not currently provide please consider
4711 contributing your translation back to the project.
4716 LOC: Config.errHtmlText
4719 HTML text to include in error messages. Make this a "mailto"
4720 URL to your admin address, or maybe just a link to your
4721 organizations Web page.
4723 To include this in your error messages, you must rewrite
4724 the error template files (found in the "errors" directory).
4725 Wherever you want the 'err_html_text' line to appear,
4726 insert a %L tag in the error template file.
4729 NAME: email_err_data
4732 LOC: Config.onoff.emailErrData
4735 If enabled, information about the occurred error will be
4736 included in the mailto links of the ERR pages (if %W is set)
4737 so that the email body contains the data.
4738 Syntax is <A HREF="mailto:%w%W">%w</A>
4743 LOC: Config.denyInfoList
4746 Usage: deny_info err_page_name acl
4747 or deny_info http://... acl
4748 Example: deny_info ERR_CUSTOM_ACCESS_DENIED bad_guys
4750 This can be used to return a ERR_ page for requests which
4751 do not pass the 'http_access' rules. Squid remembers the last
4752 acl it evaluated in http_access, and if a 'deny_info' line exists
4753 for that ACL Squid returns a corresponding error page.
4755 The acl is typically the last acl on the http_access deny line which
4756 denied access. The exceptions to this rule are:
4757 - When Squid needs to request authentication credentials. It's then
4758 the first authentication related acl encountered
4759 - When none of the http_access lines matches. It's then the last
4760 acl processed on the last http_access line.
4762 You may use ERR_ pages that come with Squid or create your own pages
4763 and put them into the configured errors/ directory.
4765 Alternatively you can specify an error URL. The browsers will
4766 get redirected (302) to the specified URL. %s in the redirection
4767 URL will be replaced by the requested URL.
4769 Alternatively you can tell Squid to reset the TCP connection
4770 by specifying TCP_RESET.
4774 OPTIONS INFLUENCING REQUEST FORWARDING
4775 -----------------------------------------------------------------------------
4778 NAME: nonhierarchical_direct
4780 LOC: Config.onoff.nonhierarchical_direct
4783 By default, Squid will send any non-hierarchical requests
4784 (matching hierarchy_stoplist or not cacheable request type) direct
4787 If you set this to off, Squid will prefer to send these
4788 requests to parents.
4790 Note that in most configurations, by turning this off you will only
4791 add latency to these request without any improvement in global hit
4794 If you are inside an firewall see never_direct instead of
4800 LOC: Config.onoff.prefer_direct
4803 Normally Squid tries to use parents for most requests. If you for some
4804 reason like it to first try going direct and only use a parent if
4805 going direct fails set this to on.
4807 By combining nonhierarchical_direct off and prefer_direct on you
4808 can set up Squid to use a parent as a backup path if going direct
4811 Note: If you want Squid to use parents for all requests see
4812 the never_direct directive. prefer_direct only modifies how Squid
4813 acts on cacheable requests.
4818 LOC: Config.accessList.AlwaysDirect
4821 Usage: always_direct allow|deny [!]aclname ...
4823 Here you can use ACL elements to specify requests which should
4824 ALWAYS be forwarded by Squid to the origin servers without using
4825 any peers. For example, to always directly forward requests for
4826 local servers ignoring any parents or siblings you may have use
4829 acl local-servers dstdomain my.domain.net
4830 always_direct allow local-servers
4832 To always forward FTP requests directly, use
4835 always_direct allow FTP
4837 NOTE: There is a similar, but opposite option named
4838 'never_direct'. You need to be aware that "always_direct deny
4839 foo" is NOT the same thing as "never_direct allow foo". You
4840 may need to use a deny rule to exclude a more-specific case of
4841 some other rule. Example:
4843 acl local-external dstdomain external.foo.net
4844 acl local-servers dstdomain .foo.net
4845 always_direct deny local-external
4846 always_direct allow local-servers
4848 NOTE: If your goal is to make the client forward the request
4849 directly to the origin server bypassing Squid then this needs
4850 to be done in the client configuration. Squid configuration
4851 can only tell Squid how Squid should fetch the object.
4853 NOTE: This directive is not related to caching. The replies
4854 is cached as usual even if you use always_direct. To not cache
4855 the replies see no_cache.
4857 This option replaces some v1.1 options such as local_domain
4863 LOC: Config.accessList.NeverDirect
4866 Usage: never_direct allow|deny [!]aclname ...
4868 never_direct is the opposite of always_direct. Please read
4869 the description for always_direct if you have not already.
4871 With 'never_direct' you can use ACL elements to specify
4872 requests which should NEVER be forwarded directly to origin
4873 servers. For example, to force the use of a proxy for all
4874 requests, except those in your local domain use something like:
4876 acl local-servers dstdomain .foo.net
4877 acl all src 0.0.0.0/0.0.0.0
4878 never_direct deny local-servers
4879 never_direct allow all
4881 or if Squid is inside a firewall and there are local intranet
4882 servers inside the firewall use something like:
4884 acl local-intranet dstdomain .foo.net
4885 acl local-external dstdomain external.foo.net
4886 always_direct deny local-external
4887 always_direct allow local-intranet
4888 never_direct allow all
4890 This option replaces some v1.1 options such as inside_firewall
4895 ADVANCED NETWORKING OPTIONS
4896 -----------------------------------------------------------------------------
4899 NAME: incoming_icp_average
4902 LOC: Config.comm_incoming.icp_average
4905 NAME: incoming_http_average
4908 LOC: Config.comm_incoming.http_average
4911 NAME: incoming_dns_average
4914 LOC: Config.comm_incoming.dns_average
4917 NAME: min_icp_poll_cnt
4920 LOC: Config.comm_incoming.icp_min_poll
4923 NAME: min_dns_poll_cnt
4926 LOC: Config.comm_incoming.dns_min_poll
4929 NAME: min_http_poll_cnt
4932 LOC: Config.comm_incoming.http_min_poll
4934 Heavy voodoo here. I can't even believe you are reading this.
4935 Are you crazy? Don't even think about adjusting these unless
4936 you understand the algorithms in comm_select.c first!
4942 LOC: Config.accept_filter
4946 The name of an accept(2) filter to install on Squid's
4947 listen socket(s). This feature is perhaps specific to
4948 FreeBSD and requires support in the kernel.
4950 The 'httpready' filter delays delivering new connections
4951 to Squid until a full HTTP request has been received.
4952 See the accf_http(9) man page for details.
4954 The 'dataready' filter delays delivering new connections
4955 to Squid until there is some data to process.
4956 See the accf_dataready(9) man page for details.
4960 The 'data' filter delays delivering of new connections
4961 to Squid until there is some data to process by TCP_ACCEPT_DEFER.
4962 You may optionally specify a number of seconds to wait by
4963 'data=N' where N is the number of seconds. Defaults to 30
4964 if not specified. See the tcp(7) man page for details.
4967 accept_filter httpready
4972 NAME: tcp_recv_bufsize
4976 LOC: Config.tcpRcvBufsz
4978 Size of receive buffer to set for TCP sockets. Probably just
4979 as easy to change your kernel's default. Set to zero to use
4980 the default buffer size.
4985 -----------------------------------------------------------------------------
4992 LOC: TheICAPConfig.onoff
4995 If you want to enable the ICAP module support, set this to on.
4998 NAME: icap_connect_timeout
5001 LOC: TheICAPConfig.connect_timeout_raw
5004 This parameter specifies how long to wait for the TCP connect to
5005 the requested ICAP server to complete before giving up and either
5006 terminating the HTTP transaction or bypassing the failure.
5008 The default for optional services is peer_connect_timeout.
5009 The default for essential services is connect_timeout.
5010 If this option is explicitly set, its value applies to all services.
5013 NAME: icap_io_timeout
5017 LOC: TheICAPConfig.io_timeout_raw
5020 This parameter specifies how long to wait for an I/O activity on
5021 an established, active ICAP connection before giving up and
5022 either terminating the HTTP transaction or bypassing the
5025 The default is read_timeout.
5028 NAME: icap_service_failure_limit
5031 LOC: TheICAPConfig.service_failure_limit
5034 The limit specifies the number of failures that Squid tolerates
5035 when establishing a new TCP connection with an ICAP service. If
5036 the number of failures exceeds the limit, the ICAP service is
5037 not used for new ICAP requests until it is time to refresh its
5038 OPTIONS. The per-service failure counter is reset to zero each
5039 time Squid fetches new service OPTIONS.
5041 A negative value disables the limit. Without the limit, an ICAP
5042 service will not be considered down due to connectivity failures
5043 between ICAP OPTIONS requests.
5046 NAME: icap_service_revival_delay
5049 LOC: TheICAPConfig.service_revival_delay
5052 The delay specifies the number of seconds to wait after an ICAP
5053 OPTIONS request failure before requesting the options again. The
5054 failed ICAP service is considered "down" until fresh OPTIONS are
5057 The actual delay cannot be smaller than the hardcoded minimum
5058 delay of 30 seconds.
5061 NAME: icap_preview_enable
5065 LOC: TheICAPConfig.preview_enable
5068 The ICAP Preview feature allows the ICAP server to handle the
5069 HTTP message by looking only at the beginning of the message body
5070 or even without receiving the body at all. In some environments,
5071 previews greatly speedup ICAP processing.
5073 During an ICAP OPTIONS transaction, the server may tell Squid what
5074 HTTP messages should be previewed and how big the preview should be.
5075 Squid will not use Preview if the server did not request one.
5077 To disable ICAP Preview for all ICAP services, regardless of
5078 individual ICAP server OPTIONS responses, set this option to "off".
5080 icap_preview_enable off
5083 NAME: icap_preview_size
5086 LOC: TheICAPConfig.preview_size
5089 The default size of preview data to be sent to the ICAP server.
5090 -1 means no preview. This value might be overwritten on a per server
5091 basis by OPTIONS requests.
5094 NAME: icap_default_options_ttl
5097 LOC: TheICAPConfig.default_options_ttl
5100 The default TTL value for ICAP OPTIONS responses that don't have
5101 an Options-TTL header.
5104 NAME: icap_persistent_connections
5108 LOC: TheICAPConfig.reuse_connections
5111 Whether or not Squid should use persistent connections to
5115 NAME: icap_send_client_ip
5119 LOC: TheICAPConfig.send_client_ip
5122 This adds the header "X-Client-IP" to ICAP requests.
5125 NAME: icap_send_client_username
5129 LOC: TheICAPConfig.send_client_username
5132 This sends authenticated HTTP client username (if available) to
5133 the ICAP service. The username value is encoded based on the
5134 icap_client_username_encode option and is sent using the header
5135 specified by the icap_client_username_header option.
5138 NAME: icap_client_username_header
5141 LOC: TheICAPConfig.client_username_header
5142 DEFAULT: X-Client-Username
5144 ICAP request header name to use for send_client_username.
5147 NAME: icap_client_username_encode
5151 LOC: TheICAPConfig.client_username_encode
5154 Whether to base64 encode the authenticated client username.
5158 TYPE: icap_service_type
5163 Defines a single ICAP service
5165 icap_service servicename vectoring_point bypass service_url
5167 vectoring_point = reqmod_precache|reqmod_postcache|respmod_precache|respmod_postcache
5168 This specifies at which point of transaction processing the
5169 ICAP service should be activated. *_postcache vectoring points
5170 are not yet supported.
5172 If set to 1, the ICAP service is treated as optional. If the
5173 service cannot be reached or malfunctions, Squid will try to
5174 ignore any errors and process the message as if the service
5175 was not enabled. No all ICAP errors can be bypassed.
5176 If set to 0, the ICAP service is treated as essential and all
5177 ICAP errors will result in an error page returned to the
5179 service_url = icap://servername:port/service
5182 icap_service service_1 reqmod_precache 0 icap://icap1.mydomain.net:1344/reqmod
5183 icap_service service_2 respmod_precache 0 icap://icap2.mydomain.net:1344/respmod
5187 TYPE: icap_class_type
5192 This depricated option was documented to define an ICAP service
5193 chain, even though it actually defined a set of similar, redundant
5194 services, and the chains were not supported.
5196 To define a set of redundant services, please use the
5197 adaptation_service_set directive.
5199 If you need adaptation service chains, patches or sponsorship
5204 TYPE: icap_access_type
5209 This option is depricated. Please use adaptation_access, which
5210 has the same ICAP functionality, but comes with better
5211 documentation, and eCAP support.
5216 -----------------------------------------------------------------------------
5219 NAME: loadable_modules
5221 IFDEF: USE_LOADABLE_MODULES
5222 LOC: Config.loadable_module_names
5225 Instructs Squid to load the specified dynamic module(s) or activate
5226 preloaded module(s).
5228 loadable_modules @DEFAULT_PREFIX@/lib/MinimalAdapter.so
5232 MESSAGE ADAPTATION OPTIONS
5233 -----------------------------------------------------------------------------
5236 NAME: adaptation_service_set
5237 TYPE: adaptation_service_set_type
5238 IFDEF: USE_ADAPTATION
5243 Defines a named adaptation service set. The set is populated in
5244 the order of adaptation_service_set directives in this file.
5245 When adaptation ACLs are processed, the first and only the first
5246 applicable adaptation service from the set will be used. Thus,
5247 the set should group similar, redundant services, rather than a
5248 chain of complementary services.
5250 If you have a single adaptation service, you do not need to
5251 define a set containing it because adaptation_access accepts
5254 See also: adaptation_access
5257 adaptation_service_set svcBlocker urlFilterPrimary urlFilterBackup
5258 adaptation service_set svcLogger loggerLocal loggerRemote
5261 NAME: adaptation_access
5262 TYPE: adaptation_access_type
5263 IFDEF: USE_ADAPTATION
5267 Sends an HTTP transaction to an ICAP or eCAP adaptation service.
5269 adaptation_access service_name allow|deny [!]aclname...
5270 adaptation_access set_name allow|deny [!]aclname...
5272 At each supported vectoring point, the adaptation_access
5273 statements are processed in the order they appear in this
5274 configuration file. Statements pointing to the following services
5275 are ignored (i.e., skipped without checking their ACL):
5277 - services serving different vectoring points
5278 - "broken-but-bypassable" services
5279 - "up" services configured to ignore such transactions
5280 (e.g., based on the ICAP Transfer-Ignore header).
5282 When a set_name is used, all services in the set are checked
5283 using the same rules, to find the first applicable one. See
5284 adaptation_service_set for details.
5286 If an access list is checked and there is a match, the
5287 processing stops: For an "allow" rule, the corresponding
5288 adaptation service is used for the transaction. For a "deny"
5289 rule, no adaptation service is activated.
5291 It is currently not possible to apply more than one adaptation
5292 service at the same vectoring point to the same HTTP transaction.
5294 See also: icap_service and ecap_service
5297 adaptation_access service_1 allow all
5302 -----------------------------------------------------------------------------
5305 NAME: check_hostnames
5308 LOC: Config.onoff.check_hostnames
5310 For security and stability reasons Squid can check
5311 hostnames for Internet standard RFC compliance. If you want
5312 Squid to perform these checks turn this directive on.
5315 NAME: allow_underscore
5318 LOC: Config.onoff.allow_underscore
5320 Underscore characters is not strictly allowed in Internet hostnames
5321 but nevertheless used by many sites. Set this to off if you want
5322 Squid to be strict about the standard.
5323 This check is performed only when check_hostnames is set to on.
5326 NAME: cache_dns_program
5328 IFDEF: USE_DNSSERVERS
5329 DEFAULT: @DEFAULT_DNSSERVER@
5330 LOC: Config.Program.dnsserver
5332 Specify the location of the executable for dnslookup process.
5337 IFDEF: USE_DNSSERVERS
5339 LOC: Config.dnsChildren
5341 The number of processes spawn to service DNS name lookups.
5342 For heavily loaded caches on large servers, you should
5343 probably increase this value to at least 10. The maximum
5344 is 32. The default is 5.
5346 You must have at least one dnsserver process.
5349 NAME: dns_retransmit_interval
5352 LOC: Config.Timeout.idns_retransmit
5353 IFDEF: !USE_DNSSERVERS
5355 Initial retransmit interval for DNS queries. The interval is
5356 doubled each time all configured DNS servers have been tried.
5363 LOC: Config.Timeout.idns_query
5364 IFDEF: !USE_DNSSERVERS
5366 DNS Query timeout. If no response is received to a DNS query
5367 within this time all DNS servers for the queried domain
5368 are assumed to be unavailable.
5375 LOC: Config.onoff.res_defnames
5377 Normally the RES_DEFNAMES resolver option is disabled
5378 (see res_init(3)). This prevents caches in a hierarchy
5379 from interpreting single-component hostnames locally. To allow
5380 Squid to handle single-component names, enable this option.
5383 NAME: dns_nameservers
5386 LOC: Config.dns_nameservers
5388 Use this if you want to specify a list of DNS name servers
5389 (IP addresses) to use instead of those given in your
5390 /etc/resolv.conf file.
5391 On Windows platforms, if no value is specified here or in
5392 the /etc/resolv.conf file, the list of DNS name servers are
5393 taken from the Windows registry, both static and dynamic DHCP
5394 configurations are supported.
5396 Example: dns_nameservers 10.0.0.1 192.172.0.4
5401 DEFAULT: @DEFAULT_HOSTS@
5402 LOC: Config.etcHostsPath
5404 Location of the host-local IP name-address associations
5405 database. Most Operating Systems have such a file on different
5407 - Un*X & Linux: /etc/hosts
5408 - Windows NT/2000: %SystemRoot%\system32\drivers\etc\hosts
5409 (%SystemRoot% value install default is c:\winnt)
5410 - Windows XP/2003: %SystemRoot%\system32\drivers\etc\hosts
5411 (%SystemRoot% value install default is c:\windows)
5412 - Windows 9x/Me: %windir%\hosts
5413 (%windir% value is usually c:\windows)
5414 - Cygwin: /etc/hosts
5416 The file contains newline-separated definitions, in the
5417 form ip_address_in_dotted_form name [name ...] names are
5418 whitespace-separated. Lines beginning with an hash (#)
5419 character are comments.
5421 The file is checked at startup and upon configuration.
5422 If set to 'none', it won't be checked.
5423 If append_domain is used, that domain will be added to
5424 domain-local (i.e. not containing any dot character) host
5430 LOC: Config.dns_testname_list
5432 DEFAULT_IF_NONE: netscape.com internic.net nlanr.net microsoft.com
5434 The DNS tests exit as soon as the first site is successfully looked up
5436 This test can be disabled with the -D command line option.
5441 LOC: Config.appendDomain
5444 Appends local domain name to hostnames without any dots in
5445 them. append_domain must begin with a period.
5447 Be warned there are now Internet names with no dots in
5448 them using only top-domain names, so setting this may
5449 cause some Internet sites to become unavailable.
5452 append_domain .yourdomain.com
5455 NAME: ignore_unknown_nameservers
5457 LOC: Config.onoff.ignore_unknown_nameservers
5460 By default Squid checks that DNS responses are received
5461 from the same IP addresses they are sent to. If they
5462 don't match, Squid ignores the response and writes a warning
5463 message to cache.log. You can allow responses from unknown
5464 nameservers by setting this option to 'off'.
5467 NAME: dns_v4_fallback
5470 LOC: Config.onoff.dns_require_A
5472 Standard practice with DNS is to lookup either A or AAAA records
5473 and use the results if it succeeds. Only looking up the other if
5474 the first attempt fails or otherwise produces no results.
5476 That policy however will cause squid to produce error pages for some
5477 servers that advertise AAAA but are unreachable over IPv6.
5479 If this is ON squid will always lookup both AAAA and A, using both.
5480 If this is OFF squid will lookup AAAA and only try A if none found.
5482 WARNING: There are some possibly unwanted side-effects with this on:
5483 *) Doubles the load placed by squid on the DNS network.
5484 *) May negatively impact connection delay times.
5488 COMMENT: (number of entries)
5491 LOC: Config.ipcache.size
5498 LOC: Config.ipcache.low
5505 LOC: Config.ipcache.high
5507 The size, low-, and high-water marks for the IP cache.
5510 NAME: fqdncache_size
5511 COMMENT: (number of entries)
5514 LOC: Config.fqdncache.size
5516 Maximum number of FQDN cache entries.
5521 -----------------------------------------------------------------------------
5528 LOC: Config.onoff.mem_pools
5530 If set, Squid will keep pools of allocated (but unused) memory
5531 available for future use. If memory is a premium on your
5532 system and you believe your malloc library outperforms Squid
5533 routines, disable this.
5536 NAME: memory_pools_limit
5540 LOC: Config.MemPools.limit
5542 Used only with memory_pools on:
5543 memory_pools_limit 50 MB
5545 If set to a non-zero value, Squid will keep at most the specified
5546 limit of allocated (but unused) memory in memory pools. All free()
5547 requests that exceed this limit will be handled by your malloc
5548 library. Squid does not pre-allocate any memory, just safe-keeps
5549 objects that otherwise would be free()d. Thus, it is safe to set
5550 memory_pools_limit to a reasonably high value even if your
5551 configuration will use less memory.
5553 If set to zero, Squid will keep all memory it can. That is, there
5554 will be no limit on the total amount of memory used for safe-keeping.
5556 To disable memory allocation optimization, do not set
5557 memory_pools_limit to 0. Set memory_pools to "off" instead.
5559 An overhead for maintaining memory pools is not taken into account
5560 when the limit is checked. This overhead is close to four bytes per
5561 object kept. However, pools may actually _save_ memory because of
5562 reduced memory thrashing in your malloc library.
5566 COMMENT: on|off|transparent|truncate|delete
5569 LOC: opt_forwarded_for
5571 If set to "on", Squid will append your client's IP address
5572 in the HTTP requests it forwards. By default it looks like:
5574 X-Forwarded-For: 192.1.2.3
5576 If set to "off", it will appear as
5578 X-Forwarded-For: unknown
5580 If set to "transparent", Squid will not alter the
5581 X-Forwarded-For header in any way.
5583 If set to "delete", Squid will delete the entire
5584 X-Forwarded-For header.
5586 If set to "truncate", Squid will remove all existing
5587 X-Forwarded-For entries, and place itself as the sole entry.
5590 NAME: cachemgr_passwd
5591 TYPE: cachemgrpasswd
5593 LOC: Config.passwd_list
5595 Specify passwords for cachemgr operations.
5597 Usage: cachemgr_passwd password action action ...
5599 Some valid actions are (see cache manager menu for a full list):
5638 * Indicates actions which will not be performed without a
5639 valid password, others can be performed if not listed here.
5641 To disable an action, set the password to "disable".
5642 To allow performing an action without a password, set the
5645 Use the keyword "all" to set the same password for all actions.
5648 cachemgr_passwd secret shutdown
5649 cachemgr_passwd lesssssssecret info stats/objects
5650 cachemgr_passwd disable all
5657 LOC: Config.onoff.client_db
5659 If you want to disable collecting per-client statistics,
5660 turn off client_db here.
5663 NAME: refresh_all_ims
5667 LOC: Config.onoff.refresh_all_ims
5669 When you enable this option, squid will always check
5670 the origin server for an update when a client sends an
5671 If-Modified-Since request. Many browsers use IMS
5672 requests when the user requests a reload, and this
5673 ensures those clients receive the latest version.
5675 By default (off), squid may return a Not Modified response
5676 based on the age of the cached version.
5679 NAME: reload_into_ims
5680 IFDEF: HTTP_VIOLATIONS
5684 LOC: Config.onoff.reload_into_ims
5686 When you enable this option, client no-cache or ``reload''
5687 requests will be changed to If-Modified-Since requests.
5688 Doing this VIOLATES the HTTP standard. Enabling this
5689 feature could make you liable for problems which it
5692 see also refresh_pattern for a more selective approach.
5695 NAME: maximum_single_addr_tries
5697 LOC: Config.retry.maxtries
5700 This sets the maximum number of connection attempts for a
5701 host that only has one address (for multiple-address hosts,
5702 each address is tried once).
5704 The default value is one attempt, the (not recommended)
5705 maximum is 255 tries. A warning message will be generated
5706 if it is set to a value greater than ten.
5708 Note: This is in addition to the request re-forwarding which
5709 takes place if Squid fails to get a satisfying response.
5712 NAME: retry_on_error
5714 LOC: Config.retry.onerror
5717 If set to on Squid will automatically retry requests when
5718 receiving an error response. This is mainly useful if you
5719 are in a complex cache hierarchy to work around access
5723 NAME: as_whois_server
5725 LOC: Config.as_whois_server
5726 DEFAULT: whois.ra.net
5727 DEFAULT_IF_NONE: whois.ra.net
5729 WHOIS server to query for AS numbers. NOTE: AS numbers are
5730 queried only when Squid starts up, not for every request.
5735 LOC: Config.onoff.offline
5738 Enable this option and Squid will never try to validate cached
5742 NAME: uri_whitespace
5743 TYPE: uri_whitespace
5744 LOC: Config.uri_whitespace
5747 What to do with requests that have whitespace characters in the
5750 strip: The whitespace characters are stripped out of the URL.
5751 This is the behavior recommended by RFC2396.
5752 deny: The request is denied. The user receives an "Invalid
5754 allow: The request is allowed and the URI is not changed. The
5755 whitespace characters remain in the URI. Note the
5756 whitespace is passed to redirector processes if they
5758 encode: The request is allowed and the whitespace characters are
5759 encoded according to RFC1738. This could be considered
5760 a violation of the HTTP/1.1
5761 RFC because proxies are not allowed to rewrite URI's.
5762 chop: The request is allowed and the URI is chopped at the
5763 first whitespace. This might also be considered a
5769 LOC: Config.coredump_dir
5771 DEFAULT_IF_NONE: none
5773 By default Squid leaves core files in the directory from where
5774 it was started. If you set 'coredump_dir' to a directory
5775 that exists, Squid will chdir() to that directory at startup
5776 and coredump files will be left there.
5779 # Leave coredumps in the first cache dir
5780 coredump_dir @DEFAULT_SWAP_DIR@
5786 LOC: Config.chroot_dir
5789 Use this to have Squid do a chroot() while initializing. This
5790 also causes Squid to fully drop root privileges after
5791 initializing. This means, for example, if you use a HTTP
5792 port less than 1024 and try to reconfigure, you will may get an
5793 error saying that Squid can not open the port.
5796 NAME: balance_on_multiple_ip
5798 LOC: Config.onoff.balance_on_multiple_ip
5801 Modern IP resolvers in squid sort lookup results by preferred access.
5802 By default squid will use these IP in order and only rotates to
5803 the next listed when the most preffered fails.
5805 Some load balancing servers based on round robin DNS have been
5806 found not to preserve user session state across requests
5807 to different IP addresses.
5809 Enabling this directive Squid rotates IP's per request.
5812 NAME: pipeline_prefetch
5814 LOC: Config.onoff.pipeline_prefetch
5817 To boost the performance of pipelined requests to closer
5818 match that of a non-proxied environment Squid can try to fetch
5819 up to two requests in parallel from a pipeline.
5821 Defaults to off for bandwidth management and access logging
5825 NAME: high_response_time_warning
5828 LOC: Config.warnings.high_rptm
5831 If the one-minute median response time exceeds this value,
5832 Squid prints a WARNING with debug level 0 to get the
5833 administrators attention. The value is in milliseconds.
5836 NAME: high_page_fault_warning
5838 LOC: Config.warnings.high_pf
5841 If the one-minute average page fault rate exceeds this
5842 value, Squid prints a WARNING with debug level 0 to get
5843 the administrators attention. The value is in page faults
5847 NAME: high_memory_warning
5849 LOC: Config.warnings.high_memory
5852 If the memory usage (as determined by mallinfo) exceeds
5853 this amount, Squid prints a WARNING with debug level 0 to get
5854 the administrators attention.
5857 NAME: sleep_after_fork
5858 COMMENT: (microseconds)
5860 LOC: Config.sleep_after_fork
5863 When this is set to a non-zero value, the main Squid process
5864 sleeps the specified number of microseconds after a fork()
5865 system call. This sleep may help the situation where your
5866 system reports fork() failures due to lack of (virtual)
5867 memory. Note, however, if you have a lot of child
5868 processes, these sleep delays will add up and your
5869 Squid will not service requests for some amount of time
5870 until all the child processes have been started.
5871 On Windows value less then 1000 (1 milliseconds) are