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
415 %>{Header} HTTP request header
417 HTTP request header list member
419 HTTP request header list member using ; as
420 list separator. ; can be any non-alphanumeric
423 %<{Header} HTTP reply header
425 HTTP reply header list member
427 HTTP reply header list member using ; as
428 list separator. ; can be any non-alphanumeric
431 In addition to the above, any string specified in the referencing
432 acl will also be included in the helper request line, after the
433 specified formats (see the "acl external" directive)
435 The helper receives lines per the above format specification,
436 and returns lines starting with OK or ERR indicating the validity
437 of the request and optionally followed by additional keywords with
440 General result syntax:
442 OK/ERR keyword=value ...
446 user= The users name (login)
447 password= The users password (for login= cache_peer option)
448 message= Message describing the reason. Available as %o
450 tag= Apply a tag to a request (for both ERR and OK results)
451 Only sets a tag, does not alter existing tags.
452 log= String to be logged in access.log. Available as
453 %ea in logformat specifications
455 If protocol=3.0 (the default) then URL escaping is used to protect
456 each value in both requests and responses.
458 If using protocol=2.5 then all values need to be enclosed in quotes
459 if they may contain whitespace, or the whitespace escaped using \.
460 And quotes or \ characters within the keyword value must be \ escaped.
462 When using the concurrency= option the protocol is changed by
463 introducing a query channel tag infront of the request/response.
464 The query channel tag is a number between 0 and concurrency-1.
472 Defining an Access List
474 Every access list definition must begin with an aclname and acltype,
475 followed by either type-specific arguments or a quoted filename that
478 acl aclname acltype argument ...
479 acl aclname acltype "file" ...
481 When using "file", the file should contain one item per line.
483 By default, regular expressions are CASE-SENSITIVE. To make
484 them case-insensitive, use the -i option.
487 ***** ACL TYPES AVAILABLE *****
489 acl aclname src ip-address/netmask ... # clients IP address
490 acl aclname src addr1-addr2/netmask ... # range of addresses
491 acl aclname dst ip-address/netmask ... # URL host's IP address
492 acl aclname myip ip-address/netmask ... # local socket IP address
494 acl aclname arp mac-address ... (xx:xx:xx:xx:xx:xx notation)
495 # The arp ACL requires the special configure option --enable-arp-acl.
496 # Furthermore, the ARP ACL code is not portable to all operating systems.
497 # It works on Linux, Solaris, Windows, FreeBSD, and some other *BSD variants.
499 # NOTE: Squid can only determine the MAC address for clients that are on
500 # the same subnet. If the client is on a different subnet, then Squid cannot
501 # find out its MAC address.
503 acl aclname srcdomain .foo.com ... # reverse lookup, from client IP
504 acl aclname dstdomain .foo.com ... # Destination server from URL
505 acl aclname srcdom_regex [-i] \.foo\.com ... # regex matching client name
506 acl aclname dstdom_regex [-i] \.foo\.com ... # regex matching server
507 # For dstdomain and dstdom_regex a reverse lookup is tried if a IP
508 # based URL is used and no match is found. The name "none" is used
509 # if the reverse lookup fails.
511 acl aclname src_as number ...
512 acl aclname dst_as number ...
513 # Except for access control, AS numbers can be used for
514 # routing of requests to specific caches. Here's an
515 # example for routing all requests for AS#1241 and only
516 # those to mycache.mydomain.net:
517 # acl asexample dst_as 1241
518 # cache_peer_access mycache.mydomain.net allow asexample
519 # cache_peer_access mycache_mydomain.net deny all
521 acl aclname time [day-abbrevs] [h1:m1-h2:m2]
530 # h1:m1 must be less than h2:m2
532 acl aclname url_regex [-i] ^http:// ... # regex matching on whole URL
533 acl aclname urlpath_regex [-i] \.gif$ ... # regex matching on URL path
535 acl aclname port 80 70 21 ...
536 acl aclname port 0-1024 ... # ranges allowed
537 acl aclname myport 3128 ... # (local socket TCP port)
538 acl aclname myportname 3128 ... # http(s)_port name
540 acl aclname proto HTTP FTP ...
542 acl aclname method GET POST ...
544 acl aclname http_status 200 301 500- 400-403 ... # status code in reply
546 acl aclname browser [-i] regexp ...
547 # pattern match on User-Agent header (see also req_header below)
549 acl aclname referer_regex [-i] regexp ...
550 # pattern match on Referer header
551 # Referer is highly unreliable, so use with care
553 acl aclname ident username ...
554 acl aclname ident_regex [-i] pattern ...
555 # string match on ident output.
556 # use REQUIRED to accept any non-null ident.
558 acl aclname proxy_auth [-i] username ...
559 acl aclname proxy_auth_regex [-i] pattern ...
560 # list of valid usernames
561 # use REQUIRED to accept any valid username.
563 # NOTE: when a Proxy-Authentication header is sent but it is not
564 # needed during ACL checking the username is NOT logged
567 # NOTE: proxy_auth requires a EXTERNAL authentication program
568 # to check username/password combinations (see
569 # auth_param directive).
571 # NOTE: proxy_auth can't be used in a transparent/intercepting proxy
572 # as the browser needs to be configured for using a proxy in order
573 # to respond to proxy authentication.
575 acl aclname snmp_community string ...
576 # A community string to limit access to your SNMP Agent
579 # acl snmppublic snmp_community public
581 acl aclname maxconn number
582 # This will be matched when the client's IP address has
583 # more than <number> HTTP connections established.
585 acl aclname max_user_ip [-s] number
586 # This will be matched when the user attempts to log in from more
587 # than <number> different ip addresses. The authenticate_ip_ttl
588 # parameter controls the timeout on the ip entries.
589 # If -s is specified the limit is strict, denying browsing
590 # from any further IP addresses until the ttl has expired. Without
591 # -s Squid will just annoy the user by "randomly" denying requests.
592 # (the counter is reset each time the limit is reached and a
594 # NOTE: in acceleration mode or where there is mesh of child proxies,
595 # clients may appear to come from multiple addresses if they are
596 # going through proxy farms, so a limit of 1 may cause user problems.
598 acl aclname req_mime_type [-i] mime-type ...
599 # regex match against the mime type of the request generated
600 # by the client. Can be used to detect file upload or some
601 # types HTTP tunneling requests.
602 # NOTE: This does NOT match the reply. You cannot use this
603 # to match the returned file type.
605 acl aclname req_header header-name [-i] any\.regex\.here
606 # regex match against any of the known request headers. May be
607 # thought of as a superset of "browser", "referer" and "mime-type"
610 acl aclname rep_mime_type [-i] mime-type ...
611 # regex match against the mime type of the reply received by
612 # squid. Can be used to detect file download or some
613 # types HTTP tunneling requests.
614 # NOTE: This has no effect in http_access rules. It only has
615 # effect in rules that affect the reply data stream such as
618 acl aclname rep_header header-name [-i] any\.regex\.here
619 # regex match against any of the known reply headers. May be
620 # thought of as a superset of "browser", "referer" and "mime-type"
623 acl aclname external class_name [arguments...]
624 # external ACL lookup via a helper class defined by the
625 # external_acl_type directive.
627 acl aclname user_cert attribute values...
628 # match against attributes in a user SSL certificate
629 # attribute is one of DN/C/O/CN/L/ST
631 acl aclname ca_cert attribute values...
632 # match against attributes a users issuing CA SSL certificate
633 # attribute is one of DN/C/O/CN/L/ST
635 acl aclname ext_user username ...
636 acl aclname ext_user_regex [-i] pattern ...
637 # string match on username returned by external acl helper
638 # use REQUIRED to accept any non-null user name.
641 acl macaddress arp 09:00:2b:23:45:67
642 acl myexample dst_as 1241
643 acl password proxy_auth REQUIRED
644 acl fileupload req_mime_type -i ^multipart/form-data$
645 acl javascript rep_mime_type -i ^application/x-javascript$
648 #Recommended minimum configuration:
649 acl manager proto cache_object
650 acl localhost src 127.0.0.1/32
651 acl to_localhost dst 127.0.0.0/8
653 # Example rule allowing access from your local networks.
654 # Adapt to list your (internal) IP networks from where browsing
656 acl localnet src 10.0.0.0/8 # RFC1918 possible internal network
657 acl localnet src 172.16.0.0/12 # RFC1918 possible internal network
658 acl localnet src 192.168.0.0/16 # RFC1918 possible internal network
660 acl SSL_ports port 443
661 acl Safe_ports port 80 # http
662 acl Safe_ports port 21 # ftp
663 acl Safe_ports port 443 # https
664 acl Safe_ports port 70 # gopher
665 acl Safe_ports port 210 # wais
666 acl Safe_ports port 1025-65535 # unregistered ports
667 acl Safe_ports port 280 # http-mgmt
668 acl Safe_ports port 488 # gss-http
669 acl Safe_ports port 591 # filemaker
670 acl Safe_ports port 777 # multiling http
671 acl CONNECT method CONNECT
675 NAME: follow_x_forwarded_for
677 IFDEF: FOLLOW_X_FORWARDED_FOR
678 LOC: Config.accessList.followXFF
680 DEFAULT_IF_NONE: deny all
682 Allowing or Denying the X-Forwarded-For header to be followed to
683 find the original source of a request.
685 Requests may pass through a chain of several other proxies
686 before reaching us. The X-Forwarded-For header will contain a
687 comma-separated list of the IP addresses in the chain, with the
688 rightmost address being the most recent.
690 If a request reaches us from a source that is allowed by this
691 configuration item, then we consult the X-Forwarded-For header
692 to see where that host received the request from. If the
693 X-Forwarded-For header contains multiple addresses, and if
694 acl_uses_indirect_client is on, then we continue backtracking
695 until we reach an address for which we are not allowed to
696 follow the X-Forwarded-For header, or until we reach the first
697 address in the list. (If acl_uses_indirect_client is off, then
698 it's impossible to backtrack through more than one level of
699 X-Forwarded-For addresses.)
701 The end result of this process is an IP address that we will
702 refer to as the indirect client address. This address may
703 be treated as the client address for access control, delay
704 pools and logging, depending on the acl_uses_indirect_client,
705 delay_pool_uses_indirect_client and log_uses_indirect_client
708 SECURITY CONSIDERATIONS:
710 Any host for which we follow the X-Forwarded-For header
711 can place incorrect information in the header, and Squid
712 will use the incorrect information as if it were the
713 source address of the request. This may enable remote
714 hosts to bypass any access control restrictions that are
715 based on the client's source addresses.
719 acl localhost src 127.0.0.1
720 acl my_other_proxy srcdomain .proxy.example.com
721 follow_x_forwarded_for allow localhost
722 follow_x_forwarded_for allow my_other_proxy
725 NAME: acl_uses_indirect_client
728 IFDEF: FOLLOW_X_FORWARDED_FOR
730 LOC: Config.onoff.acl_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 acl matching.
737 NAME: delay_pool_uses_indirect_client
740 IFDEF: FOLLOW_X_FORWARDED_FOR && DELAY_POOLS
742 LOC: Config.onoff.delay_pool_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 delay pools.
749 NAME: log_uses_indirect_client
752 IFDEF: FOLLOW_X_FORWARDED_FOR
754 LOC: Config.onoff.log_uses_indirect_client
756 Controls whether the indirect client address
757 (see follow_x_forwarded_for) is used instead of the
758 direct client address in the access log.
763 LOC: Config.accessList.http
765 DEFAULT_IF_NONE: deny all
767 Allowing or Denying access based on defined access lists
769 Access to the HTTP port:
770 http_access allow|deny [!]aclname ...
772 NOTE on default values:
774 If there are no "access" lines present, the default is to deny
777 If none of the "access" lines cause a match, the default is the
778 opposite of the last line in the list. If the last line was
779 deny, the default is allow. Conversely, if the last line
780 is allow, the default will be deny. For these reasons, it is a
781 good idea to have an "deny all" or "allow all" entry at the end
782 of your access lists to avoid potential confusion.
785 #Recommended minimum configuration:
787 # Only allow cachemgr access from localhost
788 http_access allow manager localhost
789 http_access deny manager
790 # Deny requests to unknown ports
791 http_access deny !Safe_ports
792 # Deny CONNECT to other than SSL ports
793 http_access deny CONNECT !SSL_ports
795 # We strongly recommend the following be uncommented to protect innocent
796 # web applications running on the proxy server who think the only
797 # one who can access services on "localhost" is a local user
798 #http_access deny to_localhost
800 # INSERT YOUR OWN RULE(S) HERE TO ALLOW ACCESS FROM YOUR CLIENTS
802 # Example rule allowing access from your local networks.
803 # Adapt localnet in the ACL section to list your (internal) IP networks
804 # from where browsing should be allowed
805 http_access allow localnet
807 # And finally deny all other access to this proxy
812 NAME: http_reply_access
814 LOC: Config.accessList.reply
817 Allow replies to client requests. This is complementary to http_access.
819 http_reply_access allow|deny [!] aclname ...
821 NOTE: if there are no access lines present, the default is to allow
824 If none of the access lines cause a match the opposite of the
825 last line will apply. Thus it is good practice to end the rules
826 with an "allow all" or "deny all" entry.
831 LOC: Config.accessList.icp
833 DEFAULT_IF_NONE: deny all
835 Allowing or Denying access to the ICP port based on defined
838 icp_access allow|deny [!]aclname ...
840 See http_access for details
843 #Allow ICP queries from local networks only
844 #icp_access allow localnet
852 LOC: Config.accessList.htcp
854 DEFAULT_IF_NONE: deny all
856 Allowing or Denying access to the HTCP port based on defined
859 htcp_access allow|deny [!]aclname ...
861 See http_access for details
863 NOTE: The default if no htcp_access lines are present is to
864 deny all traffic. This default may cause problems with peers
865 using the htcp or htcp-oldsquid options.
868 #Allow HTCP queries from local networks only
869 #htcp_access allow localnet
870 #htcp_access deny all
874 NAME: htcp_clr_access
877 LOC: Config.accessList.htcp_clr
879 DEFAULT_IF_NONE: deny all
881 Allowing or Denying access to purge content using HTCP based
882 on defined access lists
884 htcp_clr_access allow|deny [!]aclname ...
886 See http_access for details
888 #Allow HTCP CLR requests from trusted peers
889 acl htcp_clr_peer src 172.16.1.2
890 htcp_clr_access allow htcp_clr_peer
895 LOC: Config.accessList.miss
898 Use to force your neighbors to use you as a sibling instead of
899 a parent. For example:
901 acl localclients src 172.16.0.0/16
902 miss_access allow localclients
903 miss_access deny !localclients
905 This means only your local clients are allowed to fetch
906 MISSES and all other clients can only fetch HITS.
908 By default, allow all clients who passed the http_access rules
909 to fetch MISSES from us.
912 NAME: ident_lookup_access
916 DEFAULT_IF_NONE: deny all
917 LOC: Config.accessList.identLookup
919 A list of ACL elements which, if matched, cause an ident
920 (RFC 931) lookup to be performed for this request. For
921 example, you might choose to always perform ident lookups
922 for your main multi-user Unix boxes, but not for your Macs
923 and PCs. By default, ident lookups are not performed for
926 To enable ident lookups for specific client addresses, you
927 can follow this example:
929 acl ident_aware_hosts src 198.168.1.0/255.255.255.0
930 ident_lookup_access allow ident_aware_hosts
931 ident_lookup_access deny all
933 Only src type ACL checks are fully supported. A src_domain
934 ACL might work at times, but it will not always provide
938 NAME: reply_body_max_size
939 COMMENT: size [acl acl...]
942 LOC: Config.ReplyBodySize
944 This option specifies the maximum size of a reply body. It can be
945 used to prevent users from downloading very large files, such as
946 MP3's and movies. When the reply headers are received, the
947 reply_body_max_size lines are processed, and the first line where
948 all (if any) listed ACLs are true is used as the maximum body size
951 This size is checked twice. First when we get the reply headers,
952 we check the content-length value. If the content length value exists
953 and is larger than the allowed size, the request is denied and the
954 user receives an error message that says "the request or reply
955 is too large." If there is no content-length, and the reply
956 size exceeds this limit, the client's connection is just closed
957 and they will receive a partial reply.
959 WARNING: downstream caches probably can not detect a partial reply
960 if there is no content-length header, so they will cache
961 partial responses and give them out as hits. You should NOT
962 use this option if you have downstream caches.
964 WARNING: A maximum size smaller than the size of squid's error messages
965 will cause an infinite loop and crash squid. Ensure that the smallest
966 non-zero value you use is greater that the maximum header size plus
967 the size of your largest error page.
969 If you set this parameter none (the default), there will be
975 -----------------------------------------------------------------------------
978 NAME: http_port ascii_port
981 LOC: Config.Sockaddr.http
983 Usage: port [options]
984 hostname:port [options]
985 1.2.3.4:port [options]
987 The socket addresses where Squid will listen for HTTP client
988 requests. You may specify multiple socket addresses.
989 There are three forms: port alone, hostname with port, and
990 IP address with port. If you specify a hostname or IP
991 address, Squid binds the socket to that specific
992 address. This replaces the old 'tcp_incoming_address'
993 option. Most likely, you do not need to bind to a specific
994 address, so you can use the port number alone.
996 If you are running Squid in accelerator mode, you
997 probably want to listen on port 80 also, or instead.
999 The -a command line option may be used to specify additional
1000 port(s) where Squid listens for proxy request. Such ports will
1001 be plain proxy ports with no options.
1003 You may specify multiple socket addresses on multiple lines.
1007 intercept Support for IP-Layer interception of
1008 outgoing requests without browser settings.
1009 NP: disables authentication and IPv6 on the port.
1011 tproxy Support Linux TPROXY for spoofing outgoing
1012 connections using the client IP address.
1013 NP: disables authentication and IPv6 on the port.
1015 accel Accelerator mode. Also needs at least one of
1016 vhost / vport / defaultsite.
1018 defaultsite=domainname
1019 What to use for the Host: header if it is not present
1020 in a request. Determines what site (not origin server)
1021 accelerators should consider the default.
1024 vhost Accelerator mode using Host header for virtual
1025 domain support. Implies accel.
1027 vport Accelerator with IP based virtual host support.
1030 vport=NN As above, but uses specified port number rather
1031 than the http_port number. Implies accel.
1033 protocol= Protocol to reconstruct accelerated requests with.
1036 disable-pmtu-discovery=
1037 Control Path-MTU discovery usage:
1038 off lets OS decide on what to do (default).
1039 transparent disable PMTU discovery when transparent
1041 always disable always PMTU discovery.
1043 In many setups of transparently intercepting proxies
1044 Path-MTU discovery can not work on traffic towards the
1045 clients. This is the case when the intercepting device
1046 does not fully track connections and fails to forward
1047 ICMP must fragment messages to the cache server. If you
1048 have such setup and experience that certain clients
1049 sporadically hang or never complete requests set
1050 disable-pmtu-discovery option to 'transparent'.
1052 sslBump Intercept each CONNECT request matching ssl_bump ACL,
1053 establish secure connection with the client and with
1054 the server, decrypt HTTP messages as they pass through
1055 Squid, and treat them as unencrypted HTTP messages,
1056 becoming the man-in-the-middle.
1058 When this option is enabled, additional options become
1059 available to specify SSL-related properties of the
1060 client-side connection: cert, key, version, cipher,
1061 options, clientca, cafile, capath, crlfile, dhparams,
1062 sslflags, and sslcontext. See the https_port directive
1063 for more information on these options.
1065 The ssl_bump option is required to fully enable
1066 the SslBump feature.
1068 name= Specifies a internal name for the port. Defaults to
1069 the port specification (port or addr:port)
1071 keepalive[=idle,interval,timeout]
1072 Enable TCP keepalive probes of idle connections
1073 idle is the initial time before TCP starts probing
1074 the connection, interval how often to probe, and
1075 timeout the time before giving up.
1077 If you run Squid on a dual-homed machine with an internal
1078 and an external interface we recommend you to specify the
1079 internal address:port in http_port. This way Squid will only be
1080 visible on the internal address.
1083 # Squid normally listens to port 3128
1084 http_port @DEFAULT_HTTP_PORT@
1090 TYPE: https_port_list
1092 LOC: Config.Sockaddr.https
1094 Usage: [ip:]port cert=certificate.pem [key=key.pem] [options...]
1096 The socket address where Squid will listen for HTTPS client
1099 This is really only useful for situations where you are running
1100 squid in accelerator mode and you want to do the SSL work at the
1103 You may specify multiple socket addresses on multiple lines,
1104 each with their own SSL certificate and/or options.
1108 accel Accelerator mode. Also needs at least one of
1109 defaultsite or vhost.
1111 defaultsite= The name of the https site presented on
1112 this port. Implies accel.
1114 vhost Accelerator mode using Host header for virtual
1115 domain support. Requires a wildcard certificate
1116 or other certificate valid for more than one domain.
1119 protocol= Protocol to reconstruct accelerated requests with.
1122 cert= Path to SSL certificate (PEM format).
1124 key= Path to SSL private key file (PEM format)
1125 if not specified, the certificate file is
1126 assumed to be a combined certificate and
1129 version= The version of SSL/TLS supported
1130 1 automatic (default)
1135 cipher= Colon separated list of supported ciphers.
1137 options= Various SSL engine options. The most important
1139 NO_SSLv2 Disallow the use of SSLv2
1140 NO_SSLv3 Disallow the use of SSLv3
1141 NO_TLSv1 Disallow the use of TLSv1
1142 SINGLE_DH_USE Always create a new key when using
1143 temporary/ephemeral DH key exchanges
1144 See src/ssl_support.c or OpenSSL SSL_CTX_set_options
1145 documentation for a complete list of options.
1147 clientca= File containing the list of CAs to use when
1148 requesting a client certificate.
1150 cafile= File containing additional CA certificates to
1151 use when verifying client certificates. If unset
1152 clientca will be used.
1154 capath= Directory containing additional CA certificates
1155 and CRL lists to use when verifying client certificates.
1157 crlfile= File of additional CRL lists to use when verifying
1158 the client certificate, in addition to CRLs stored in
1159 the capath. Implies VERIFY_CRL flag below.
1161 dhparams= File containing DH parameters for temporary/ephemeral
1164 sslflags= Various flags modifying the use of SSL:
1166 Don't request client certificates
1167 immediately, but wait until acl processing
1168 requires a certificate (not yet implemented).
1170 Don't use the default CA lists built in
1173 Don't allow for session reuse. Each connection
1174 will result in a new SSL session.
1176 Verify CRL lists when accepting client
1179 Verify CRL lists for all certificates in the
1180 client certificate chain.
1182 sslcontext= SSL session ID context identifier.
1184 vport Accelerator with IP based virtual host support.
1186 vport=NN As above, but uses specified port number rather
1187 than the https_port number. Implies accel.
1189 name= Specifies a internal name for the port. Defaults to
1190 the port specification (port or addr:port)
1194 NAME: tcp_outgoing_tos tcp_outgoing_ds tcp_outgoing_dscp
1197 LOC: Config.accessList.outgoing_tos
1199 Allows you to select a TOS/Diffserv value to mark outgoing
1200 connections with, based on the username or source address
1203 tcp_outgoing_tos ds-field [!]aclname ...
1205 Example where normal_service_net uses the TOS value 0x00
1206 and normal_service_net uses 0x20
1208 acl normal_service_net src 10.0.0.0/255.255.255.0
1209 acl good_service_net src 10.0.1.0/255.255.255.0
1210 tcp_outgoing_tos 0x00 normal_service_net
1211 tcp_outgoing_tos 0x20 good_service_net
1213 TOS/DSCP values really only have local significance - so you should
1214 know what you're specifying. For more information, see RFC2474 and
1217 The TOS/DSCP byte must be exactly that - a octet value 0 - 255, or
1218 "default" to use whatever default your host has. Note that in
1219 practice often only values 0 - 63 is usable as the two highest bits
1220 have been redefined for use by ECN (RFC3168).
1222 Processing proceeds in the order specified, and stops at first fully
1225 Note: The use of this directive using client dependent ACLs is
1226 incompatible with the use of server side persistent connections. To
1227 ensure correct results it is best to set server_persisten_connections
1228 to off when using this directive in such configurations.
1231 NAME: clientside_tos
1234 LOC: Config.accessList.clientside_tos
1236 Allows you to select a TOS/Diffserv value to mark client-side
1237 connections with, based on the username or source address
1245 LOC: Config.zph_tos_local
1247 Allows you to select a TOS/Diffserv value to mark local hits. Read above
1248 (tcp_outgoing_tos) for details/requirements about TOS.
1249 Default: 0 (disabled).
1256 LOC: Config.zph_tos_peer
1258 Allows you to select a TOS/Diffserv value to mark peer hits. Read above
1259 (tcp_outgoing_tos) for details/requirements about TOS.
1260 Default: 0 (disabled).
1263 NAME: zph_tos_parent
1268 LOC: Config.onoff.zph_tos_parent
1270 Set this to off if you want only sibling hits to be marked.
1271 If set to on (default), parent hits are being marked too.
1274 NAME: zph_preserve_miss_tos
1279 LOC: Config.onoff.zph_preserve_miss_tos
1281 If set to on (default), any HTTP response towards clients will
1282 have the TOS value of the response comming from the remote
1283 server masked with the value of zph_preserve_miss_tos_mask.
1284 For this to work correctly, you will need to patch your linux
1285 kernel with the TOS preserving ZPH patch.
1286 The kernel patch can be downloaded from http://zph.bratcheda.org
1289 NAME: zph_preserve_miss_tos_mask
1293 LOC: Config.zph_preserve_miss_tos_mask
1295 Allows you to mask certain bits in the TOS received from the
1296 remote server, before copying the value to the TOS send towards
1298 Default: 255 (TOS from server is not changed).
1301 NAME: tcp_outgoing_address
1304 LOC: Config.accessList.outgoing_address
1306 Allows you to map requests to different outgoing IP addresses
1307 based on the username or source address of the user making
1310 tcp_outgoing_address ipaddr [[!]aclname] ...
1312 Example where requests from 10.0.0.0/24 will be forwarded
1313 with source address 10.1.0.1, 10.0.2.0/24 forwarded with
1314 source address 10.1.0.2 and the rest will be forwarded with
1315 source address 10.1.0.3.
1317 acl normal_service_net src 10.0.0.0/24
1318 acl good_service_net src 10.0.2.0/24
1319 tcp_outgoing_address 10.1.0.1 normal_service_net
1320 tcp_outgoing_address 10.1.0.2 good_service_net
1321 tcp_outgoing_address 10.1.0.3
1323 Processing proceeds in the order specified, and stops at first fully
1326 Note: The use of this directive using client dependent ACLs is
1327 incompatible with the use of server side persistent connections. To
1328 ensure correct results it is best to set server_persistent_connections
1329 to off when using this directive in such configurations.
1334 Squid is built with a capability of bridging the IPv4 and IPv6 internets.
1335 tcp_outgoing_address as exampled above breaks this bridging by forcing
1336 all outbound traffic through a certain IPv4 which may be on the wrong
1337 side of the IPv4/IPv6 boundary.
1339 To operate with tcp_outgoing_address and keep the bridging benefits
1340 an additional ACL needs to be used which ensures the IPv6-bound traffic
1341 is never forced or permitted out the IPv4 interface.
1343 acl to_ipv6 dst ipv6
1344 tcp_outgoing_address 2002::c001 good_service_net to_ipv6
1345 tcp_outgoing_address 10.1.0.2 good_service_net !to_ipv6
1347 tcp_outgoing_address 2002::beef normal_service_net to_ipv6
1348 tcp_outgoing_address 10.1.0.1 normal_service_net !to_ipv6
1350 tcp_outgoing_address 2002::1 to_ipv6
1351 tcp_outgoing_address 10.1.0.3 !to_ipv6
1356 -----------------------------------------------------------------------------
1359 NAME: ssl_unclean_shutdown
1363 LOC: Config.SSL.unclean_shutdown
1365 Some browsers (especially MSIE) bugs out on SSL shutdown
1372 LOC: Config.SSL.ssl_engine
1375 The OpenSSL engine to use. You will need to set this if you
1376 would like to use hardware SSL acceleration for example.
1379 NAME: sslproxy_client_certificate
1382 LOC: Config.ssl_client.cert
1385 Client SSL Certificate to use when proxying https:// URLs
1388 NAME: sslproxy_client_key
1391 LOC: Config.ssl_client.key
1394 Client SSL Key to use when proxying https:// URLs
1397 NAME: sslproxy_version
1400 LOC: Config.ssl_client.version
1403 SSL version level to use when proxying https:// URLs
1406 NAME: sslproxy_options
1409 LOC: Config.ssl_client.options
1412 SSL engine options to use when proxying https:// URLs
1415 NAME: sslproxy_cipher
1418 LOC: Config.ssl_client.cipher
1421 SSL cipher list to use when proxying https:// URLs
1424 NAME: sslproxy_cafile
1427 LOC: Config.ssl_client.cafile
1430 file containing CA certificates to use when verifying server
1431 certificates while proxying https:// URLs
1434 NAME: sslproxy_capath
1437 LOC: Config.ssl_client.capath
1440 directory containing CA certificates to use when verifying
1441 server certificates while proxying https:// URLs
1447 LOC: Config.accessList.ssl_bump
1450 This ACL controls which CONNECT requests to an http_port
1451 marked with an sslBump flag are actually "bumped". Please
1452 see the sslBump flag of an http_port option for more details
1453 about decoding proxied SSL connections.
1455 By default, no requests are bumped.
1457 See also: http_port sslBump
1460 # Example: Bump all requests except those originating from localhost and
1461 # those going to webax.com or example.com sites.
1463 # acl localhost src 127.0.0.1/32
1464 # acl broken_sites dstdomain .webax.com
1465 # acl broken_sites dstdomain .example.com
1466 # ssl_bump deny localhost
1467 # ssl_bump deny broken_sites
1468 # ssl_bump allow all
1472 NAME: sslproxy_flags
1475 LOC: Config.ssl_client.flags
1478 Various flags modifying the use of SSL while proxying https:// URLs:
1479 DONT_VERIFY_PEER Accept certificates that fail verification.
1480 For refined control, see sslproxy_cert_error.
1481 NO_DEFAULT_CA Don't use the default CA list built in
1486 NAME: sslproxy_cert_error
1489 LOC: Config.ssl_client.cert_error
1492 Use this ACL to bypass server certificate validation errors.
1494 For example, the following lines will bypass all validation errors
1495 when talking to servers located at 172.16.0.0/16. All other
1496 validation errors will result in ERR_SECURE_CONNECT_FAIL error.
1498 acl BrokenServersAtTrustedIP dst 172.16.0.0/16
1499 sslproxy_cert_error allow BrokenServersAtTrustedIP
1500 sslproxy_cert_error deny all
1502 This option must use fast ACL expressions only. Expressions that use
1503 external lookups or communication result in unpredictable behavior or
1506 Without this option, all server certificate validation errors
1507 terminate the transaction. Bypassing validation errors is dangerous
1508 because an error usually implies that the server cannot be trusted and
1509 the connection may be insecure.
1511 See also: sslproxy_flags and DONT_VERIFY_PEER.
1515 # sslproxy_cert_error deny all
1521 NAME: sslpassword_program
1524 LOC: Config.Program.ssl_password
1527 Specify a program used for entering SSL key passphrases
1528 when using encrypted SSL certificate keys. If not specified
1529 keys must either be unencrypted, or Squid started with the -N
1530 option to allow it to query interactively for the passphrase.
1534 OPTIONS WHICH AFFECT THE NEIGHBOR SELECTION ALGORITHM
1535 -----------------------------------------------------------------------------
1543 To specify other caches in a hierarchy, use the format:
1545 cache_peer hostname type http-port icp-port [options]
1550 # hostname type port port options
1551 # -------------------- -------- ----- ----- -----------
1552 cache_peer parent.foo.net parent 3128 3130 proxy-only default
1553 cache_peer sib1.foo.net sibling 3128 3130 proxy-only
1554 cache_peer sib2.foo.net sibling 3128 3130 proxy-only
1556 type: either 'parent', 'sibling', or 'multicast'.
1558 proxy-port: The port number where the cache listens for proxy
1561 icp-port: Used for querying neighbor caches about
1562 objects. To have a non-ICP neighbor
1563 specify '0' for the ICP port.
1564 NOTE: Also requires icp_port option enabled to send/receive
1565 requests via this method.
1575 weighted-round-robin
1584 login=user:password | PASS | *:password
1599 sslcert=/path/to/ssl/certificate
1600 sslkey=/path/to/ssl/key
1604 front-end-https[=on|auto]
1606 use 'proxy-only' to specify objects fetched
1607 from this cache should not be saved locally.
1609 use 'weight=n' to affect the selection of a peer
1610 during any weighted peer-selection mechanisms.
1611 The weight must be an integer; default is 1,
1612 larger weights are favored more.
1613 This option does not affect parent selection if a peering
1614 protocol is not in use.
1616 use 'basetime=n' to specify a base amount to
1617 be subtracted from round trip times of parents.
1618 It is subtracted before division by weight in calculating
1619 which parent to fectch from. If the rtt is less than the
1620 base time the rtt is set to a minimal value.
1622 use 'ttl=n' to specify a IP multicast TTL to use
1623 when sending an ICP queries to this address.
1624 Only useful when sending to a multicast group.
1625 Because we don't accept ICP replies from random
1626 hosts, you must configure other group members as
1627 peers with the 'multicast-responder' option below.
1629 use 'no-query' to NOT send ICP queries to this
1632 use 'background-ping' to only send ICP queries to this
1633 neighbor infrequently. This is used to keep the neighbor
1634 round trip time updated and is usually used in
1635 conjunction with weighted-round-robin.
1637 use 'default' if this is a parent cache which can
1638 be used as a "last-resort" if a peer cannot be located
1639 by any of the peer-selection mechanisms.
1640 If specified more than once, only the first is used.
1642 use 'round-robin' to define a set of parents which
1643 should be used in a round-robin fashion in the
1644 absence of any ICP queries.
1646 use 'weighted-round-robin' to define a set of parents
1647 which should be used in a round-robin fashion with the
1648 frequency of each parent being based on the round trip
1649 time. Closer parents are used more often.
1650 Usually used for background-ping parents.
1652 use 'carp' to define a set of parents which should
1653 be used as a CARP array. The requests will be
1654 distributed among the parents based on the CARP load
1655 balancing hash function based on their weight.
1657 use 'userhash' to load-balance amongst a set of parents
1658 based on the client proxy_auth or ident username.
1660 use 'sourcehash' to load-balance amongst a set of parents
1661 based on the client source ip.
1663 'multicast-responder' indicates the named peer
1664 is a member of a multicast group. ICP queries will
1665 not be sent directly to the peer, but ICP replies
1666 will be accepted from it.
1668 'closest-only' indicates that, for ICP_OP_MISS
1669 replies, we'll only forward CLOSEST_PARENT_MISSes
1670 and never FIRST_PARENT_MISSes.
1672 use 'no-digest' to NOT request cache digests from
1675 'no-netdb-exchange' disables requesting ICMP
1676 RTT database (NetDB) from the neighbor.
1678 use 'no-delay' to prevent access to this neighbor
1679 from influencing the delay pools.
1681 use 'login=user:password' if this is a personal/workgroup
1682 proxy and your parent requires proxy authentication.
1683 Note: The string can include URL escapes (i.e. %20 for
1684 spaces). This also means % must be written as %%.
1686 use 'login=PASS' if users must authenticate against
1687 the upstream proxy or in the case of a reverse proxy
1688 configuration, the origin web server. This will pass
1689 the users credentials as they are to the peer.
1690 This only works for the Basic HTTP authentication scheme.
1691 Note: To combine this with proxy_auth both proxies must
1692 share the same user database as HTTP only allows for
1693 a single login (one for proxy, one for origin server).
1694 Also be warned this will expose your users proxy
1695 password to the peer. USE WITH CAUTION
1697 use 'login=*:password' to pass the username to the
1698 upstream cache, but with a fixed password. This is meant
1699 to be used when the peer is in another administrative
1700 domain, but it is still needed to identify each user.
1701 The star can optionally be followed by some extra
1702 information which is added to the username. This can
1703 be used to identify this proxy to the peer, similar to
1704 the login=username:password option above.
1706 use 'connect-timeout=nn' to specify a peer
1707 specific connect timeout (also see the
1708 peer_connect_timeout directive)
1710 use 'digest-url=url' to tell Squid to fetch the cache
1711 digest (if digests are enabled) for this host from
1712 the specified URL rather than the Squid default
1715 use 'allow-miss' to disable Squid's use of only-if-cached
1716 when forwarding requests to siblings. This is primarily
1717 useful when icp_hit_stale is used by the sibling. To
1718 extensive use of this option may result in forwarding
1719 loops, and you should avoid having two-way peerings
1720 with this option. (for example to deny peer usage on
1721 requests from peer by denying cache_peer_access if the
1724 use 'max-conn=n' to limit the amount of connections Squid
1725 may open to this peer.
1727 use 'htcp' to send HTCP, instead of ICP, queries
1728 to the neighbor. You probably also want to
1729 set the "icp port" to 4827 instead of 3130.
1730 You MUST also set htcp_access expicitly. The default of
1731 deny all will prevent peer traffic.
1733 use 'htcp-oldsquid' to send HTCP to old Squid versions
1734 You MUST also set htcp_access expicitly. The default of
1735 deny all will prevent peer traffic.
1737 use 'htcp-no-clr' to send HTCP to the neighbor but without
1738 sending any CLR requests. This cannot be used with
1741 use 'htcp-no-purge-clr' to send HTCP to the neighbor
1742 including CLRs but only when they do not result from
1745 use 'htcp-only-clr' to send HTCP to the neighbor but ONLY
1746 CLR requests. This cannot be used with htcp-no-clr.
1748 use 'htcp-forward-clr' to forward any HTCP CLR requests
1749 this proxy receives to the peer.
1751 'originserver' causes this parent peer to be contacted as
1752 a origin server. Meant to be used in accelerator setups.
1754 use 'name=xxx' if you have multiple peers on the same
1755 host but different ports. This name can be used to
1756 differentiate the peers in cache_peer_access and similar
1759 use 'forceddomain=name' to forcibly set the Host header
1760 of requests forwarded to this peer. Useful in accelerator
1761 setups where the server (peer) expects a certain domain
1762 name and using redirectors to feed this domain name
1765 use 'ssl' to indicate connections to this peer should
1766 be SSL/TLS encrypted.
1768 use 'sslcert=/path/to/ssl/certificate' to specify a client
1769 SSL certificate to use when connecting to this peer.
1771 use 'sslkey=/path/to/ssl/key' to specify the private SSL
1772 key corresponding to sslcert above. If 'sslkey' is not
1773 specified 'sslcert' is assumed to reference a
1774 combined file containing both the certificate and the key.
1776 use sslversion=1|2|3|4 to specify the SSL version to use
1777 when connecting to this peer
1778 1 = automatic (default)
1783 use sslcipher=... to specify the list of valid SSL ciphers
1784 to use when connecting to this peer.
1786 use ssloptions=... to specify various SSL engine options:
1787 NO_SSLv2 Disallow the use of SSLv2
1788 NO_SSLv3 Disallow the use of SSLv3
1789 NO_TLSv1 Disallow the use of TLSv1
1790 See src/ssl_support.c or the OpenSSL documentation for
1791 a more complete list.
1793 use sslcafile=... to specify a file containing
1794 additional CA certificates to use when verifying the
1797 use sslcapath=... to specify a directory containing
1798 additional CA certificates to use when verifying the
1801 use sslcrlfile=... to specify a certificate revocation
1802 list file to use when verifying the peer certificate.
1804 use sslflags=... to specify various flags modifying the
1807 Accept certificates even if they fail to
1810 Don't use the default CA list built in
1813 Don't verify the peer certificate
1814 matches the server name
1816 use ssldomain= to specify the peer name as advertised
1817 in it's certificate. Used for verifying the correctness
1818 of the received peer certificate. If not specified the
1819 peer hostname will be used.
1821 use front-end-https to enable the "Front-End-Https: On"
1822 header needed when using Squid as a SSL frontend in front
1823 of Microsoft OWA. See MS KB document Q307347 for details
1824 on this header. If set to auto the header will
1825 only be added if the request is forwarded as a https://
1829 NAME: cache_peer_domain cache_host_domain
1834 Use to limit the domains for which a neighbor cache will be
1837 cache_peer_domain cache-host domain [domain ...]
1838 cache_peer_domain cache-host !domain
1840 For example, specifying
1842 cache_peer_domain parent.foo.net .edu
1844 has the effect such that UDP query packets are sent to
1845 'bigserver' only when the requested object exists on a
1846 server in the .edu domain. Prefixing the domainname
1847 with '!' means the cache will be queried for objects
1850 NOTE: * Any number of domains may be given for a cache-host,
1851 either on the same or separate lines.
1852 * When multiple domains are given for a particular
1853 cache-host, the first matched domain is applied.
1854 * Cache hosts with no domain restrictions are queried
1856 * There are no defaults.
1857 * There is also a 'cache_peer_access' tag in the ACL
1861 NAME: cache_peer_access
1866 Similar to 'cache_peer_domain' but provides more flexibility by
1869 cache_peer_access cache-host allow|deny [!]aclname ...
1871 The syntax is identical to 'http_access' and the other lists of
1872 ACL elements. See the comments for 'http_access' below, or
1873 the Squid FAQ (http://www.squid-cache.org/FAQ/FAQ-10.html).
1876 NAME: neighbor_type_domain
1877 TYPE: hostdomaintype
1881 usage: neighbor_type_domain neighbor parent|sibling domain domain ...
1883 Modifying the neighbor type for specific domains is now
1884 possible. You can treat some domains differently than the the
1885 default neighbor type specified on the 'cache_peer' line.
1886 Normally it should only be necessary to list domains which
1887 should be treated differently because the default neighbor type
1888 applies for hostnames which do not match domains listed here.
1891 cache_peer cache.foo.org parent 3128 3130
1892 neighbor_type_domain cache.foo.org sibling .com .net
1893 neighbor_type_domain cache.foo.org sibling .au .de
1896 NAME: dead_peer_timeout
1900 LOC: Config.Timeout.deadPeer
1902 This controls how long Squid waits to declare a peer cache
1903 as "dead." If there are no ICP replies received in this
1904 amount of time, Squid will declare the peer dead and not
1905 expect to receive any further ICP replies. However, it
1906 continues to send ICP queries, and will mark the peer as
1907 alive upon receipt of the first subsequent ICP reply.
1909 This timeout also affects when Squid expects to receive ICP
1910 replies from peers. If more than 'dead_peer' seconds have
1911 passed since the last ICP reply was received, Squid will not
1912 expect to receive an ICP reply on the next query. Thus, if
1913 your time between requests is greater than this timeout, you
1914 will see a lot of requests sent DIRECT to origin servers
1915 instead of to your parents.
1918 NAME: hierarchy_stoplist
1921 LOC: Config.hierarchy_stoplist
1923 A list of words which, if found in a URL, cause the object to
1924 be handled directly by this cache. In other words, use this
1925 to not query neighbor caches for certain objects. You may
1926 list this option multiple times.
1927 Note: never_direct overrides this option.
1929 #We recommend you to use at least the following line.
1930 hierarchy_stoplist cgi-bin ?
1935 MEMORY CACHE OPTIONS
1936 -----------------------------------------------------------------------------
1943 LOC: Config.memMaxSize
1945 NOTE: THIS PARAMETER DOES NOT SPECIFY THE MAXIMUM PROCESS SIZE.
1946 IT ONLY PLACES A LIMIT ON HOW MUCH ADDITIONAL MEMORY SQUID WILL
1947 USE AS A MEMORY CACHE OF OBJECTS. SQUID USES MEMORY FOR OTHER
1948 THINGS AS WELL. SEE THE SQUID FAQ SECTION 8 FOR DETAILS.
1950 'cache_mem' specifies the ideal amount of memory to be used
1952 * In-Transit objects
1954 * Negative-Cached objects
1956 Data for these objects are stored in 4 KB blocks. This
1957 parameter specifies the ideal upper limit on the total size of
1958 4 KB blocks allocated. In-Transit objects take the highest
1961 In-transit objects have priority over the others. When
1962 additional space is needed for incoming data, negative-cached
1963 and hot objects will be released. In other words, the
1964 negative-cached and hot objects will fill up any unused space
1965 not needed for in-transit objects.
1967 If circumstances require, this limit will be exceeded.
1968 Specifically, if your incoming request rate requires more than
1969 'cache_mem' of memory to hold in-transit objects, Squid will
1970 exceed this limit to satisfy the new requests. When the load
1971 decreases, blocks will be freed until the high-water mark is
1972 reached. Thereafter, blocks will be used to store hot
1976 NAME: maximum_object_size_in_memory
1980 LOC: Config.Store.maxInMemObjSize
1982 Objects greater than this size will not be attempted to kept in
1983 the memory cache. This should be set high enough to keep objects
1984 accessed frequently in memory to improve performance whilst low
1985 enough to keep larger objects from hoarding cache_mem.
1988 NAME: memory_replacement_policy
1990 LOC: Config.memPolicy
1993 The memory replacement policy parameter determines which
1994 objects are purged from memory when memory space is needed.
1996 See cache_replacement_policy for details.
2001 -----------------------------------------------------------------------------
2004 NAME: cache_replacement_policy
2006 LOC: Config.replPolicy
2009 The cache replacement policy parameter determines which
2010 objects are evicted (replaced) when disk space is needed.
2012 lru : Squid's original list based LRU policy
2013 heap GDSF : Greedy-Dual Size Frequency
2014 heap LFUDA: Least Frequently Used with Dynamic Aging
2015 heap LRU : LRU policy implemented using a heap
2017 Applies to any cache_dir lines listed below this.
2019 The LRU policies keeps recently referenced objects.
2021 The heap GDSF policy optimizes object hit rate by keeping smaller
2022 popular objects in cache so it has a better chance of getting a
2023 hit. It achieves a lower byte hit rate than LFUDA though since
2024 it evicts larger (possibly popular) objects.
2026 The heap LFUDA policy keeps popular objects in cache regardless of
2027 their size and thus optimizes byte hit rate at the expense of
2028 hit rate since one large, popular object will prevent many
2029 smaller, slightly less popular objects from being cached.
2031 Both policies utilize a dynamic aging mechanism that prevents
2032 cache pollution that can otherwise occur with frequency-based
2033 replacement policies.
2035 NOTE: if using the LFUDA replacement policy you should increase
2036 the value of maximum_object_size above its default of 4096 KB to
2037 to maximize the potential byte hit rate improvement of LFUDA.
2039 For more information about the GDSF and LFUDA cache replacement
2040 policies see http://www.hpl.hp.com/techreports/1999/HPL-1999-69.html
2041 and http://fog.hpl.external.hp.com/techreports/98/HPL-98-173.html.
2047 LOC: Config.cacheSwap
2051 cache_dir Type Directory-Name Fs-specific-data [options]
2053 You can specify multiple cache_dir lines to spread the
2054 cache among different disk partitions.
2056 Type specifies the kind of storage system to use. Only "ufs"
2057 is built by default. To enable any of the other storage systems
2058 see the --enable-storeio configure option.
2060 'Directory' is a top-level directory where cache swap
2061 files will be stored. If you want to use an entire disk
2062 for caching, this can be the mount-point directory.
2063 The directory must exist and be writable by the Squid
2064 process. Squid will NOT create this directory for you.
2068 "ufs" is the old well-known Squid storage format that has always
2071 cache_dir ufs Directory-Name Mbytes L1 L2 [options]
2073 'Mbytes' is the amount of disk space (MB) to use under this
2074 directory. The default is 100 MB. Change this to suit your
2075 configuration. Do NOT put the size of your disk drive here.
2076 Instead, if you want Squid to use the entire disk drive,
2077 subtract 20% and use that value.
2079 'Level-1' is the number of first-level subdirectories which
2080 will be created under the 'Directory'. The default is 16.
2082 'Level-2' is the number of second-level subdirectories which
2083 will be created under each first-level directory. The default
2086 The aufs store type:
2088 "aufs" uses the same storage format as "ufs", utilizing
2089 POSIX-threads to avoid blocking the main Squid process on
2090 disk-I/O. This was formerly known in Squid as async-io.
2092 cache_dir aufs Directory-Name Mbytes L1 L2 [options]
2094 see argument descriptions under ufs above
2096 The diskd store type:
2098 "diskd" uses the same storage format as "ufs", utilizing a
2099 separate process to avoid blocking the main Squid process on
2102 cache_dir diskd Directory-Name Mbytes L1 L2 [options] [Q1=n] [Q2=n]
2104 see argument descriptions under ufs above
2106 Q1 specifies the number of unacknowledged I/O requests when Squid
2107 stops opening new files. If this many messages are in the queues,
2108 Squid won't open new files. Default is 64
2110 Q2 specifies the number of unacknowledged messages when Squid
2111 starts blocking. If this many messages are in the queues,
2112 Squid blocks until it receives some replies. Default is 72
2114 When Q1 < Q2 (the default), the cache directory is optimized
2115 for lower response time at the expense of a decrease in hit
2116 ratio. If Q1 > Q2, the cache directory is optimized for
2117 higher hit ratio at the expense of an increase in response
2120 The coss store type:
2122 block-size=n defines the "block size" for COSS cache_dir's.
2123 Squid uses file numbers as block numbers. Since file numbers
2124 are limited to 24 bits, the block size determines the maximum
2125 size of the COSS partition. The default is 512 bytes, which
2126 leads to a maximum cache_dir size of 512<<24, or 8 GB. Note
2127 you should not change the coss block size after Squid
2128 has written some objects to the cache_dir.
2130 The coss file store has changed from 2.5. Now it uses a file
2131 called 'stripe' in the directory names in the config - and
2132 this will be created by squid -z.
2136 no-store, no new objects should be stored to this cache_dir
2138 max-size=n, refers to the max object size this storedir supports.
2139 It is used to initially choose the storedir to dump the object.
2140 Note: To make optimal use of the max-size limits you should order
2141 the cache_dir lines with the smallest max-size value first and the
2142 ones with no max-size specification last.
2144 Note for coss, max-size must be less than COSS_MEMBUF_SZ,
2145 which can be changed with the --with-coss-membuf-size=N configure
2148 # cache_dir ufs @DEFAULT_SWAP_DIR@ 100 16 256
2152 NAME: store_dir_select_algorithm
2154 LOC: Config.store_dir_select_algorithm
2157 Set this to 'round-robin' as an alternative.
2160 NAME: max_open_disk_fds
2162 LOC: Config.max_open_disk_fds
2165 To avoid having disk as the I/O bottleneck Squid can optionally
2166 bypass the on-disk cache if more than this amount of disk file
2167 descriptors are open.
2169 A value of 0 indicates no limit.
2172 NAME: minimum_object_size
2176 LOC: Config.Store.minObjectSize
2178 Objects smaller than this size will NOT be saved on disk. The
2179 value is specified in kilobytes, and the default is 0 KB, which
2180 means there is no minimum.
2183 NAME: maximum_object_size
2187 LOC: Config.Store.maxObjectSize
2189 Objects larger than this size will NOT be saved on disk. The
2190 value is specified in kilobytes, and the default is 4MB. If
2191 you wish to get a high BYTES hit ratio, you should probably
2192 increase this (one 32 MB object hit counts for 3200 10KB
2193 hits). If you wish to increase speed more than your want to
2194 save bandwidth you should leave this low.
2196 NOTE: if using the LFUDA replacement policy you should increase
2197 this value to maximize the byte hit rate improvement of LFUDA!
2198 See replacement_policy below for a discussion of this policy.
2201 NAME: cache_swap_low
2202 COMMENT: (percent, 0-100)
2205 LOC: Config.Swap.lowWaterMark
2208 NAME: cache_swap_high
2209 COMMENT: (percent, 0-100)
2212 LOC: Config.Swap.highWaterMark
2215 The low- and high-water marks for cache object replacement.
2216 Replacement begins when the swap (disk) usage is above the
2217 low-water mark and attempts to maintain utilization near the
2218 low-water mark. As swap utilization gets close to high-water
2219 mark object eviction becomes more aggressive. If utilization is
2220 close to the low-water mark less replacement is done each time.
2222 Defaults are 90% and 95%. If you have a large cache, 5% could be
2223 hundreds of MB. If this is the case you may wish to set these
2224 numbers closer together.
2229 -----------------------------------------------------------------------------
2234 LOC: Config.Log.logformats
2239 logformat <name> <format specification>
2241 Defines an access log format.
2243 The <format specification> is a string with embedded % format codes
2245 % format codes all follow the same basic structure where all but
2246 the formatcode is optional. Output strings are automatically escaped
2247 as required according to their context and the output format
2248 modifiers are usually not needed, but can be specified if an explicit
2249 output format is desired.
2251 % ["|[|'|#] [-] [[0]width] [{argument}] formatcode
2253 " output in quoted string format
2254 [ output in squid text log format as used by log_mime_hdrs
2255 # output in URL quoted format
2259 width field width. If starting with 0 the
2260 output is zero padded
2261 {arg} argument such as header name etc
2265 >a Client source IP address
2267 >p Client source port
2268 <A Server IP address or peer name
2269 la Local IP address (http_port)
2270 lp Local port number (http_port)
2271 ts Seconds since epoch
2272 tu subsecond time (milliseconds)
2273 tl Local time. Optional strftime format argument
2274 default %d/%b/%Y:%H:%M:%S %z
2275 tg GMT time. Optional strftime format argument
2276 default %d/%b/%Y:%H:%M:%S %z
2277 tr Response time (milliseconds)
2278 >h Request header. Optional header name argument
2279 on the format header[:[separator]element]
2280 <h Reply header. Optional header name argument
2283 ul User name from authentication
2284 ui User name from ident
2285 us User name from SSL
2286 ue User name from external acl helper
2288 Ss Squid request status (TCP_MISS etc)
2289 Sh Squid hierarchy status (DEFAULT_PARENT etc)
2290 mt MIME content type
2291 rm Request method (GET/POST etc)
2293 rp Request URL-Path excluding hostname
2294 rv Request protocol version
2295 et Tag returned by external acl
2296 ea Log string returned by external acl
2297 <st Reply size including HTTP headers
2298 >st Request size including HTTP headers
2299 st Request+Reply size including HTTP headers
2300 <sH Reply high offset sent
2301 <sS Upstream object size
2302 % a literal % character
2304 The default formats available (which do not need re-defining) are:
2306 logformat squid %ts.%03tu %6tr %>a %Ss/%03Hs %<st %rm %ru %un %Sh/%<A %mt
2307 logformat squidmime %ts.%03tu %6tr %>a %Ss/%03Hs %<st %rm %ru %un %Sh/%<A %mt [%>h] [%<h]
2308 logformat common %>a %ui %un [%tl] "%rm %ru HTTP/%rv" %Hs %<st %Ss:%Sh
2309 logformat combined %>a %ui %un [%tl] "%rm %ru HTTP/%rv" %Hs %<st "%{Referer}>h" "%{User-Agent}>h" %Ss:%Sh
2312 NAME: access_log cache_access_log
2314 LOC: Config.Log.accesslogs
2315 DEFAULT: @DEFAULT_ACCESS_LOG@ squid
2317 These files log client request activities. Has a line every HTTP or
2318 ICP request. The format is:
2319 access_log <filepath> [<logformat name> [acl acl ...]]
2320 access_log none [acl acl ...]]
2322 Will log to the specified file using the specified format (which
2323 must be defined in a logformat directive) those entries which match
2324 ALL the acl's specified (which must be defined in acl clauses).
2325 If no acl is specified, all requests will be logged to this file.
2327 To disable logging of a request use the filepath "none", in which case
2328 a logformat name should not be specified.
2330 To log the request via syslog specify a filepath of "syslog":
2332 access_log syslog[:facility.priority] [format [acl1 [acl2 ....]]]
2333 where facility could be any of:
2334 authpriv, daemon, local0 .. local7 or user.
2336 And priority could be any of:
2337 err, warning, notice, info, debug.
2340 access_log @DEFAULT_ACCESS_LOG@ squid
2345 LOC: Config.accessList.log
2347 COMMENT: allow|deny acl acl...
2349 This options allows you to control which requests gets logged
2350 to access.log (see access_log directive). Requests denied for
2351 logging will also not be accounted for in performance counters.
2356 DEFAULT: @DEFAULT_CACHE_LOG@
2359 Cache logging file. This is where general information about
2360 your cache's behavior goes. You can increase the amount of data
2361 logged to this file with the "debug_options" tag below.
2364 NAME: cache_store_log
2367 LOC: Config.Log.store
2369 Logs the activities of the storage manager. Shows which
2370 objects are ejected from the cache, and which objects are
2371 saved and for how long. To disable, enter "none" or remove the line.
2372 There are not really utilities to analyze this data, so you can safely
2375 # cache_store_log @DEFAULT_STORE_LOG@
2379 NAME: cache_swap_state cache_swap_log
2381 LOC: Config.Log.swap
2384 Location for the cache "swap.state" file. This index file holds
2385 the metadata of objects saved on disk. It is used to rebuild
2386 the cache during startup. Normally this file resides in each
2387 'cache_dir' directory, but you may specify an alternate
2388 pathname here. Note you must give a full filename, not just
2389 a directory. Since this is the index for the whole object
2390 list you CANNOT periodically rotate it!
2392 If %s can be used in the file name it will be replaced with a
2393 a representation of the cache_dir name where each / is replaced
2394 with '.'. This is needed to allow adding/removing cache_dir
2395 lines when cache_swap_log is being used.
2397 If have more than one 'cache_dir', and %s is not used in the name
2398 these swap logs will have names such as:
2404 The numbered extension (which is added automatically)
2405 corresponds to the order of the 'cache_dir' lines in this
2406 configuration file. If you change the order of the 'cache_dir'
2407 lines in this file, these index files will NOT correspond to
2408 the correct 'cache_dir' entry (unless you manually rename
2409 them). We recommend you do NOT use this option. It is
2410 better to keep these index files in each 'cache_dir' directory.
2413 NAME: logfile_rotate
2416 LOC: Config.Log.rotateNumber
2418 Specifies the number of logfile rotations to make when you
2419 type 'squid -k rotate'. The default is 10, which will rotate
2420 with extensions 0 through 9. Setting logfile_rotate to 0 will
2421 disable the file name rotation, but the logfiles are still closed
2422 and re-opened. This will enable you to rename the logfiles
2423 yourself just before sending the rotate signal.
2425 Note, the 'squid -k rotate' command normally sends a USR1
2426 signal to the running squid process. In certain situations
2427 (e.g. on Linux with Async I/O), USR1 is used for other
2428 purposes, so -k rotate uses another signal. It is best to get
2429 in the habit of using 'squid -k rotate' instead of 'kill -USR1
2433 NAME: emulate_httpd_log
2437 LOC: Config.onoff.common_log
2439 The Cache can emulate the log file format which many 'httpd'
2440 programs use. To disable/enable this emulation, set
2441 emulate_httpd_log to 'off' or 'on'. The default
2442 is to use the native log format since it includes useful
2443 information Squid-specific log analyzers use.
2446 NAME: log_ip_on_direct
2450 LOC: Config.onoff.log_ip_on_direct
2452 Log the destination IP address in the hierarchy log tag when going
2453 direct. Earlier Squid versions logged the hostname here. If you
2454 prefer the old way set this to off.
2459 DEFAULT: @DEFAULT_MIME_TABLE@
2460 LOC: Config.mimeTablePathname
2462 Pathname to Squid's MIME table. You shouldn't need to change
2463 this, but the default file contains examples and formatting
2464 information if you do.
2470 LOC: Config.onoff.log_mime_hdrs
2473 The Cache can record both the request and the response MIME
2474 headers for each HTTP transaction. The headers are encoded
2475 safely and will appear as two bracketed fields at the end of
2476 the access log (for either the native or httpd-emulated log
2477 formats). To enable this logging set log_mime_hdrs to 'on'.
2482 LOC: Config.Log.useragent
2484 IFDEF: USE_USERAGENT_LOG
2486 Squid will write the User-Agent field from HTTP requests
2487 to the filename specified here. By default useragent_log
2491 NAME: referer_log referrer_log
2493 LOC: Config.Log.referer
2495 IFDEF: USE_REFERER_LOG
2497 Squid will write the Referer field from HTTP requests to the
2498 filename specified here. By default referer_log is disabled.
2499 Note that "referer" is actually a misspelling of "referrer"
2500 however the misspelt version has been accepted into the HTTP RFCs
2506 DEFAULT: @DEFAULT_PID_FILE@
2507 LOC: Config.pidFilename
2509 A filename to write the process-id to. To disable, enter "none".
2515 LOC: Config.debugOptions
2517 Logging options are set as section,level where each source file
2518 is assigned a unique section. Lower levels result in less
2519 output, Full debugging (level 9) can result in a very large
2520 log file, so be careful. The magic word "ALL" sets debugging
2521 levels for all sections. We recommend normally running with
2529 LOC: Config.onoff.log_fqdn
2531 Turn this on if you wish to log fully qualified domain names
2532 in the access.log. To do this Squid does a DNS lookup of all
2533 IP's connecting to it. This can (in some situations) increase
2534 latency, which makes your cache seem slower for interactive
2538 NAME: client_netmask
2540 LOC: Config.Addrs.client_netmask
2541 DEFAULT: 255.255.255.255
2543 A netmask for client addresses in logfiles and cachemgr output.
2544 Change this to protect the privacy of your cache clients.
2545 A netmask of 255.255.255.0 will log all IP's in that range with
2546 the last digit set to '0'.
2553 LOC: Config.Log.forward
2555 Logs the server-side requests.
2557 This is currently work in progress.
2560 NAME: strip_query_terms
2562 LOC: Config.onoff.strip_query_terms
2565 By default, Squid strips query terms from requested URLs before
2566 logging. This protects your user's privacy.
2573 LOC: Config.onoff.buffered_logs
2575 cache.log log file is written with stdio functions, and as such
2576 it can be buffered or unbuffered. By default it will be unbuffered.
2577 Buffering it can speed up the writing slightly (though you are
2578 unlikely to need to worry unless you run with tons of debugging
2579 enabled in which case performance will suffer badly anyway..).
2582 NAME: netdb_filename
2584 DEFAULT: @DEFAULT_NETDB_FILE@
2585 LOC: Config.netdbFilename
2588 A filename where Squid stores it's netdb state between restarts.
2589 To disable, enter "none".
2593 OPTIONS FOR FTP GATEWAYING
2594 -----------------------------------------------------------------------------
2600 LOC: Config.Ftp.anon_user
2602 If you want the anonymous login password to be more informative
2603 (and enable the use of picky ftp servers), set this to something
2604 reasonable for your domain, like wwwuser@somewhere.net
2606 The reason why this is domainless by default is the
2607 request can be made on the behalf of a user in any domain,
2608 depending on how the cache is used.
2609 Some ftp server also validate the email address is valid
2610 (for example perl.com).
2613 NAME: ftp_list_width
2616 LOC: Config.Ftp.list_width
2618 Sets the width of ftp listings. This should be set to fit in
2619 the width of a standard browser. Setting this too small
2620 can cut off long filenames when browsing ftp sites.
2626 LOC: Config.Ftp.passive
2628 If your firewall does not allow Squid to use passive
2629 connections, turn off this option.
2631 Use of ftp_epsv_all option requires this to be ON.
2637 LOC: Config.Ftp.epsv_all
2639 FTP Protocol extensions permit the use of a special "EPSV ALL" command.
2641 NATs may be able to put the connection on a "fast path" through the
2642 translator, as the EPRT command will never be used and therefore,
2643 translation of the data portion of the segments will never be needed.
2645 When a client only expects to do two-way FTP transfers this may be useful.
2646 If squid finds that it must do a three-way FTP transfer after issuing
2647 an EPSV ALL command, the FTP session will fail.
2649 If you have any doubts about this option do not use it.
2650 Squid will nicely attempt all other connection methods.
2652 Requires ftp_passive to be ON (default)
2655 NAME: ftp_sanitycheck
2658 LOC: Config.Ftp.sanitycheck
2660 For security and data integrity reasons Squid by default performs
2661 sanity checks of the addresses of FTP data connections ensure the
2662 data connection is to the requested server. If you need to allow
2663 FTP connections to servers using another IP address for the data
2664 connection turn this off.
2667 NAME: ftp_telnet_protocol
2670 LOC: Config.Ftp.telnet
2672 The FTP protocol is officially defined to use the telnet protocol
2673 as transport channel for the control connection. However, many
2674 implementations are broken and does not respect this aspect of
2677 If you have trouble accessing files with ASCII code 255 in the
2678 path or similar problems involving this ASCII code you can
2679 try setting this directive to off. If that helps, report to the
2680 operator of the FTP server in question that their FTP server
2681 is broken and does not follow the FTP standard.
2685 OPTIONS FOR EXTERNAL SUPPORT PROGRAMS
2686 -----------------------------------------------------------------------------
2691 DEFAULT: @DEFAULT_DISKD@
2692 LOC: Config.Program.diskd
2694 Specify the location of the diskd executable.
2695 Note this is only useful if you have compiled in
2696 diskd as one of the store io modules.
2699 NAME: unlinkd_program
2702 DEFAULT: @DEFAULT_UNLINKD@
2703 LOC: Config.Program.unlinkd
2705 Specify the location of the executable for file deletion process.
2708 NAME: pinger_program
2710 DEFAULT: @DEFAULT_PINGER@
2711 LOC: Config.pinger.program
2714 Specify the location of the executable for the pinger process.
2720 LOC: Config.pinger.enable
2723 Control whether the pinger is active at run-time.
2724 Enables turning ICMP pinger on and off with a simple squid -k reconfigure.
2729 OPTIONS FOR URL REWRITING
2730 -----------------------------------------------------------------------------
2733 NAME: url_rewrite_program redirect_program
2735 LOC: Config.Program.redirect
2738 Specify the location of the executable for the URL rewriter.
2739 Since they can perform almost any function there isn't one included.
2741 For each requested URL rewriter will receive on line with the format
2743 URL <SP> client_ip "/" fqdn <SP> user <SP> method [<SP> kvpairs]<NL>
2745 In the future, the rewriter interface will be extended with
2746 key=value pairs ("kvpairs" shown above). Rewriter programs
2747 should be prepared to receive and possibly ignore additional
2748 whitespace-separated tokens on each input line.
2750 And the rewriter may return a rewritten URL. The other components of
2751 the request line does not need to be returned (ignored if they are).
2753 The rewriter can also indicate that a client-side redirect should
2754 be performed to the new URL. This is done by prefixing the returned
2755 URL with "301:" (moved permanently) or 302: (moved temporarily).
2757 By default, a URL rewriter is not used.
2760 NAME: url_rewrite_children redirect_children
2763 LOC: Config.redirectChildren
2765 The number of redirector processes to spawn. If you start
2766 too few Squid will have to wait for them to process a backlog of
2767 URLs, slowing it down. If you start too many they will use RAM
2768 and other system resources.
2771 NAME: url_rewrite_concurrency redirect_concurrency
2774 LOC: Config.redirectConcurrency
2776 The number of requests each redirector helper can handle in
2777 parallel. Defaults to 0 which indicates the redirector
2778 is a old-style single threaded redirector.
2781 NAME: url_rewrite_host_header redirect_rewrites_host_header
2784 LOC: Config.onoff.redir_rewrites_host
2786 By default Squid rewrites any Host: header in redirected
2787 requests. If you are running an accelerator this may
2788 not be a wanted effect of a redirector.
2790 WARNING: Entries are cached on the result of the URL rewriting
2791 process, so be careful if you have domain-virtual hosts.
2794 NAME: url_rewrite_access redirector_access
2797 LOC: Config.accessList.redirector
2799 If defined, this access list specifies which requests are
2800 sent to the redirector processes. By default all requests
2804 NAME: url_rewrite_bypass redirector_bypass
2806 LOC: Config.onoff.redirector_bypass
2809 When this is 'on', a request will not go through the
2810 redirector if all redirectors are busy. If this is 'off'
2811 and the redirector queue grows too large, Squid will exit
2812 with a FATAL error and ask you to increase the number of
2813 redirectors. You should only enable this if the redirectors
2814 are not critical to your caching system. If you use
2815 redirectors for access control, and you enable this option,
2816 users may have access to pages they should not
2817 be allowed to request.
2821 OPTIONS FOR TUNING THE CACHE
2822 -----------------------------------------------------------------------------
2825 NAME: cache no_cache
2828 LOC: Config.accessList.noCache
2830 A list of ACL elements which, if matched and denied, cause the request to
2831 not be satisfied from the cache and the reply to not be cached.
2832 In other words, use this to force certain objects to never be cached.
2834 You must use the words 'allow' or 'deny' to indicate whether items
2835 matching the ACL should be allowed or denied into the cache.
2837 Default is to allow all to be cached.
2840 NAME: refresh_pattern
2841 TYPE: refreshpattern
2845 usage: refresh_pattern [-i] regex min percent max [options]
2847 By default, regular expressions are CASE-SENSITIVE. To make
2848 them case-insensitive, use the -i option.
2850 'Min' is the time (in minutes) an object without an explicit
2851 expiry time should be considered fresh. The recommended
2852 value is 0, any higher values may cause dynamic applications
2853 to be erroneously cached unless the application designer
2854 has taken the appropriate actions.
2856 'Percent' is a percentage of the objects age (time since last
2857 modification age) an object without explicit expiry time
2858 will be considered fresh.
2860 'Max' is an upper limit on how long objects without an explicit
2861 expiry time will be considered fresh.
2863 options: override-expire
2873 override-expire enforces min age even if the server
2874 sent an explicit expiry time (e.g., with the
2875 Expires: header or Cache-Control: max-age). Doing this
2876 VIOLATES the HTTP standard. Enabling this feature
2877 could make you liable for problems which it causes.
2879 override-lastmod enforces min age even on objects
2880 that were modified recently.
2882 reload-into-ims changes client no-cache or ``reload''
2883 to If-Modified-Since requests. Doing this VIOLATES the
2884 HTTP standard. Enabling this feature could make you
2885 liable for problems which it causes.
2887 ignore-reload ignores a client no-cache or ``reload''
2888 header. Doing this VIOLATES the HTTP standard. Enabling
2889 this feature could make you liable for problems which
2892 ignore-no-cache ignores any ``Pragma: no-cache'' and
2893 ``Cache-control: no-cache'' headers received from a server.
2894 The HTTP RFC never allows the use of this (Pragma) header
2895 from a server, only a client, though plenty of servers
2898 ignore-no-store ignores any ``Cache-control: no-store''
2899 headers received from a server. Doing this VIOLATES
2900 the HTTP standard. Enabling this feature could make you
2901 liable for problems which it causes.
2903 ignore-private ignores any ``Cache-control: private''
2904 headers received from a server. Doing this VIOLATES
2905 the HTTP standard. Enabling this feature could make you
2906 liable for problems which it causes.
2908 ignore-auth caches responses to requests with authorization,
2909 as if the originserver had sent ``Cache-control: public''
2910 in the response header. Doing this VIOLATES the HTTP standard.
2911 Enabling this feature could make you liable for problems which
2914 refresh-ims causes squid to contact the origin server
2915 when a client issues an If-Modified-Since request. This
2916 ensures that the client will receive an updated version
2917 if one is available.
2919 Basically a cached object is:
2921 FRESH if expires < now, else STALE
2923 FRESH if lm-factor < percent, else STALE
2927 The refresh_pattern lines are checked in the order listed here.
2928 The first entry which matches is used. If none of the entries
2929 match the default will be used.
2931 Note, you must uncomment all the default lines if you want
2932 to change one. The default setting is only active if none is
2937 refresh_pattern ^ftp: 1440 20% 10080
2938 refresh_pattern ^gopher: 1440 0% 1440
2939 refresh_pattern -i (/cgi-bin/|\?) 0 0% 0
2940 refresh_pattern . 0 20% 4320
2944 NAME: quick_abort_min
2948 LOC: Config.quickAbort.min
2951 NAME: quick_abort_max
2955 LOC: Config.quickAbort.max
2958 NAME: quick_abort_pct
2962 LOC: Config.quickAbort.pct
2964 The cache by default continues downloading aborted requests
2965 which are almost completed (less than 16 KB remaining). This
2966 may be undesirable on slow (e.g. SLIP) links and/or very busy
2967 caches. Impatient users may tie up file descriptors and
2968 bandwidth by repeatedly requesting and immediately aborting
2971 When the user aborts a request, Squid will check the
2972 quick_abort values to the amount of data transfered until
2975 If the transfer has less than 'quick_abort_min' KB remaining,
2976 it will finish the retrieval.
2978 If the transfer has more than 'quick_abort_max' KB remaining,
2979 it will abort the retrieval.
2981 If more than 'quick_abort_pct' of the transfer has completed,
2982 it will finish the retrieval.
2984 If you do not want any retrieval to continue after the client
2985 has aborted, set both 'quick_abort_min' and 'quick_abort_max'
2988 If you want retrievals to always continue if they are being
2989 cached set 'quick_abort_min' to '-1 KB'.
2992 NAME: read_ahead_gap
2993 COMMENT: buffer-size
2995 LOC: Config.readAheadGap
2998 The amount of data the cache will buffer ahead of what has been
2999 sent to the client when retrieving an object from another server.
3003 IFDEF: HTTP_VIOLATIONS
3006 LOC: Config.negativeTtl
3009 Set the Default Time-to-Live (TTL) for failed requests.
3010 Certain types of failures (such as "connection refused" and
3011 "404 Not Found") are able to be negatively-cached for a short time.
3012 Modern web servers should provide Expires: header, however if they
3013 do not this can provide a minimum TTL.
3014 The default is not to cache errors with unknown expiry details.
3016 Note that this is different from negative caching of DNS lookups.
3018 WARNING: Doing this VIOLATES the HTTP standard. Enabling
3019 this feature could make you liable for problems which it
3023 NAME: positive_dns_ttl
3026 LOC: Config.positiveDnsTtl
3029 Upper limit on how long Squid will cache positive DNS responses.
3030 Default is 6 hours (360 minutes). This directive must be set
3031 larger than negative_dns_ttl.
3034 NAME: negative_dns_ttl
3037 LOC: Config.negativeDnsTtl
3040 Time-to-Live (TTL) for negative caching of failed DNS lookups.
3041 This also sets the lower cache limit on positive lookups.
3042 Minimum value is 1 second, and it is not recommendable to go
3043 much below 10 seconds.
3046 NAME: range_offset_limit
3049 LOC: Config.rangeOffsetLimit
3052 Sets a upper limit on how far into the the file a Range request
3053 may be to cause Squid to prefetch the whole file. If beyond this
3054 limit Squid forwards the Range request as it is and the result
3057 This is to stop a far ahead range request (lets say start at 17MB)
3058 from making Squid fetch the whole object up to that point before
3059 sending anything to the client.
3061 A value of -1 causes Squid to always fetch the object from the
3062 beginning so it may cache the result. (2.0 style)
3064 A value of 0 causes Squid to never fetch more than the
3065 client requested. (default)
3068 NAME: minimum_expiry_time
3071 LOC: Config.minimum_expiry_time
3074 The minimum caching time according to (Expires - Date)
3075 Headers Squid honors if the object can't be revalidated
3076 defaults to 60 seconds. In reverse proxy environments it
3077 might be desirable to honor shorter object lifetimes. It
3078 is most likely better to make your server return a
3079 meaningful Last-Modified header however. In ESI environments
3080 where page fragments often have short lifetimes, this will
3081 often be best set to 0.
3084 NAME: store_avg_object_size
3088 LOC: Config.Store.avgObjectSize
3090 Average object size, used to estimate number of objects your
3091 cache can hold. The default is 13 KB.
3094 NAME: store_objects_per_bucket
3097 LOC: Config.Store.objectsPerBucket
3099 Target number of objects per bucket in the store hash table.
3100 Lowering this value increases the total number of buckets and
3101 also the storage maintenance rate. The default is 20.
3106 -----------------------------------------------------------------------------
3109 NAME: request_header_max_size
3113 LOC: Config.maxRequestHeaderSize
3115 This specifies the maximum size for HTTP headers in a request.
3116 Request headers are usually relatively small (about 512 bytes).
3117 Placing a limit on the request header size will catch certain
3118 bugs (for example with persistent connections) and possibly
3119 buffer-overflow or denial-of-service attacks.
3122 NAME: reply_header_max_size
3126 LOC: Config.maxReplyHeaderSize
3128 This specifies the maximum size for HTTP headers in a reply.
3129 Reply headers are usually relatively small (about 512 bytes).
3130 Placing a limit on the reply header size will catch certain
3131 bugs (for example with persistent connections) and possibly
3132 buffer-overflow or denial-of-service attacks.
3135 NAME: request_body_max_size
3139 LOC: Config.maxRequestBodySize
3141 This specifies the maximum size for an HTTP request body.
3142 In other words, the maximum size of a PUT/POST request.
3143 A user who attempts to send a request with a body larger
3144 than this limit receives an "Invalid Request" error message.
3145 If you set this parameter to a zero (the default), there will
3146 be no limit imposed.
3152 LOC: Config.accessList.brokenPosts
3154 A list of ACL elements which, if matched, causes Squid to send
3155 an extra CRLF pair after the body of a PUT/POST request.
3157 Some HTTP servers has broken implementations of PUT/POST,
3158 and rely on an extra CRLF pair sent by some WWW clients.
3160 Quote from RFC2616 section 4.1 on this matter:
3162 Note: certain buggy HTTP/1.0 client implementations generate an
3163 extra CRLF's after a POST request. To restate what is explicitly
3164 forbidden by the BNF, an HTTP/1.1 client must not preface or follow
3165 a request with an extra CRLF.
3168 acl buggy_server url_regex ^http://....
3169 broken_posts allow buggy_server
3173 IFDEF: HTTP_VIOLATIONS
3177 LOC: Config.onoff.via
3179 If set (default), Squid will include a Via header in requests and
3180 replies as required by RFC2616.
3186 LOC: Config.onoff.ie_refresh
3189 Microsoft Internet Explorer up until version 5.5 Service
3190 Pack 1 has an issue with transparent proxies, wherein it
3191 is impossible to force a refresh. Turning this on provides
3192 a partial fix to the problem, by causing all IMS-REFRESH
3193 requests from older IE versions to check the origin server
3194 for fresh content. This reduces hit ratio by some amount
3195 (~10% in my experience), but allows users to actually get
3196 fresh content when they want it. Note because Squid
3197 cannot tell if the user is using 5.5 or 5.5SP1, the behavior
3198 of 5.5 is unchanged from old versions of Squid (i.e. a
3199 forced refresh is impossible). Newer versions of IE will,
3200 hopefully, continue to have the new behavior and will be
3201 handled based on that assumption. This option defaults to
3202 the old Squid behavior, which is better for hit ratios but
3203 worse for clients using IE, if they need to be able to
3204 force fresh content.
3207 NAME: vary_ignore_expire
3210 LOC: Config.onoff.vary_ignore_expire
3213 Many HTTP servers supporting Vary gives such objects
3214 immediate expiry time with no cache-control header
3215 when requested by a HTTP/1.0 client. This option
3216 enables Squid to ignore such expiry times until
3217 HTTP/1.1 is fully implemented.
3218 WARNING: This may eventually cause some varying
3219 objects not intended for caching to get cached.
3222 NAME: request_entities
3224 LOC: Config.onoff.request_entities
3227 Squid defaults to deny GET and HEAD requests with request entities,
3228 as the meaning of such requests are undefined in the HTTP standard
3229 even if not explicitly forbidden.
3231 Set this directive to on if you have clients which insists
3232 on sending request entities in GET or HEAD requests. But be warned
3233 that there is server software (both proxies and web servers) which
3234 can fail to properly process this kind of request which may make you
3235 vulnerable to cache pollution attacks if enabled.
3238 NAME: request_header_access
3239 IFDEF: HTTP_VIOLATIONS
3240 TYPE: http_header_access[]
3241 LOC: Config.request_header_access
3244 Usage: request_header_access header_name allow|deny [!]aclname ...
3246 WARNING: Doing this VIOLATES the HTTP standard. Enabling
3247 this feature could make you liable for problems which it
3250 This option replaces the old 'anonymize_headers' and the
3251 older 'http_anonymizer' option with something that is much
3252 more configurable. This new method creates a list of ACLs
3253 for each header, allowing you very fine-tuned header
3256 This option only applies to request headers, i.e., from the
3257 client to the server.
3259 You can only specify known headers for the header name.
3260 Other headers are reclassified as 'Other'. You can also
3261 refer to all the headers with 'All'.
3263 For example, to achieve the same behavior as the old
3264 'http_anonymizer standard' option, you should use:
3266 request_header_access From deny all
3267 request_header_access Referer deny all
3268 request_header_access Server deny all
3269 request_header_access User-Agent deny all
3270 request_header_access WWW-Authenticate deny all
3271 request_header_access Link deny all
3273 Or, to reproduce the old 'http_anonymizer paranoid' feature
3276 request_header_access Allow allow all
3277 request_header_access Authorization allow all
3278 request_header_access WWW-Authenticate allow all
3279 request_header_access Proxy-Authorization allow all
3280 request_header_access Proxy-Authenticate allow all
3281 request_header_access Cache-Control allow all
3282 request_header_access Content-Encoding allow all
3283 request_header_access Content-Length allow all
3284 request_header_access Content-Type allow all
3285 request_header_access Date allow all
3286 request_header_access Expires allow all
3287 request_header_access Host allow all
3288 request_header_access If-Modified-Since allow all
3289 request_header_access Last-Modified allow all
3290 request_header_access Location allow all
3291 request_header_access Pragma allow all
3292 request_header_access Accept allow all
3293 request_header_access Accept-Charset allow all
3294 request_header_access Accept-Encoding allow all
3295 request_header_access Accept-Language allow all
3296 request_header_access Content-Language allow all
3297 request_header_access Mime-Version allow all
3298 request_header_access Retry-After allow all
3299 request_header_access Title allow all
3300 request_header_access Connection allow all
3301 request_header_access Proxy-Connection allow all
3302 request_header_access All deny all
3304 although many of those are HTTP reply headers, and so should be
3305 controlled with the reply_header_access directive.
3307 By default, all headers are allowed (no anonymizing is
3311 NAME: reply_header_access
3312 IFDEF: HTTP_VIOLATIONS
3313 TYPE: http_header_access[]
3314 LOC: Config.reply_header_access
3317 Usage: reply_header_access header_name allow|deny [!]aclname ...
3319 WARNING: Doing this VIOLATES the HTTP standard. Enabling
3320 this feature could make you liable for problems which it
3323 This option only applies to reply headers, i.e., from the
3324 server to the client.
3326 This is the same as request_header_access, but in the other
3329 This option replaces the old 'anonymize_headers' and the
3330 older 'http_anonymizer' option with something that is much
3331 more configurable. This new method creates a list of ACLs
3332 for each header, allowing you very fine-tuned header
3335 You can only specify known headers for the header name.
3336 Other headers are reclassified as 'Other'. You can also
3337 refer to all the headers with 'All'.
3339 For example, to achieve the same behavior as the old
3340 'http_anonymizer standard' option, you should use:
3342 reply_header_access From deny all
3343 reply_header_access Referer deny all
3344 reply_header_access Server deny all
3345 reply_header_access User-Agent deny all
3346 reply_header_access WWW-Authenticate deny all
3347 reply_header_access Link deny all
3349 Or, to reproduce the old 'http_anonymizer paranoid' feature
3352 reply_header_access Allow allow all
3353 reply_header_access Authorization allow all
3354 reply_header_access WWW-Authenticate allow all
3355 reply_header_access Proxy-Authorization allow all
3356 reply_header_access Proxy-Authenticate allow all
3357 reply_header_access Cache-Control allow all
3358 reply_header_access Content-Encoding allow all
3359 reply_header_access Content-Length allow all
3360 reply_header_access Content-Type allow all
3361 reply_header_access Date allow all
3362 reply_header_access Expires allow all
3363 reply_header_access Host allow all
3364 reply_header_access If-Modified-Since allow all
3365 reply_header_access Last-Modified allow all
3366 reply_header_access Location allow all
3367 reply_header_access Pragma allow all
3368 reply_header_access Accept allow all
3369 reply_header_access Accept-Charset allow all
3370 reply_header_access Accept-Encoding allow all
3371 reply_header_access Accept-Language allow all
3372 reply_header_access Content-Language allow all
3373 reply_header_access Mime-Version allow all
3374 reply_header_access Retry-After allow all
3375 reply_header_access Title allow all
3376 reply_header_access Connection allow all
3377 reply_header_access Proxy-Connection allow all
3378 reply_header_access All deny all
3380 although the HTTP request headers won't be usefully controlled
3381 by this directive -- see request_header_access for details.
3383 By default, all headers are allowed (no anonymizing is
3387 NAME: header_replace
3388 IFDEF: HTTP_VIOLATIONS
3389 TYPE: http_header_replace[]
3390 LOC: Config.request_header_access
3393 Usage: header_replace header_name message
3394 Example: header_replace User-Agent Nutscrape/1.0 (CP/M; 8-bit)
3396 This option allows you to change the contents of headers
3397 denied with header_access above, by replacing them with
3398 some fixed string. This replaces the old fake_user_agent
3401 This only applies to request headers, not reply headers.
3403 By default, headers are removed if denied.
3406 NAME: relaxed_header_parser
3407 COMMENT: on|off|warn
3409 LOC: Config.onoff.relaxed_header_parser
3412 In the default "on" setting Squid accepts certain forms
3413 of non-compliant HTTP messages where it is unambiguous
3414 what the sending application intended even if the message
3415 is not correctly formatted. The messages is then normalized
3416 to the correct form when forwarded by Squid.
3418 If set to "warn" then a warning will be emitted in cache.log
3419 each time such HTTP error is encountered.
3421 If set to "off" then such HTTP errors will cause the request
3422 or response to be rejected.
3427 -----------------------------------------------------------------------------
3430 NAME: forward_timeout
3433 LOC: Config.Timeout.forward
3436 This parameter specifies how long Squid should at most attempt in
3437 finding a forwarding path for the request before giving up.
3440 NAME: connect_timeout
3443 LOC: Config.Timeout.connect
3446 This parameter specifies how long to wait for the TCP connect to
3447 the requested server or peer to complete before Squid should
3448 attempt to find another path where to forward the request.
3451 NAME: peer_connect_timeout
3454 LOC: Config.Timeout.peer_connect
3457 This parameter specifies how long to wait for a pending TCP
3458 connection to a peer cache. The default is 30 seconds. You
3459 may also set different timeout values for individual neighbors
3460 with the 'connect-timeout' option on a 'cache_peer' line.
3466 LOC: Config.Timeout.read
3469 The read_timeout is applied on server-side connections. After
3470 each successful read(), the timeout will be extended by this
3471 amount. If no data is read again after this amount of time,
3472 the request is aborted and logged with ERR_READ_TIMEOUT. The
3473 default is 15 minutes.
3476 NAME: request_timeout
3478 LOC: Config.Timeout.request
3481 How long to wait for an HTTP request after initial
3482 connection establishment.
3485 NAME: persistent_request_timeout
3487 LOC: Config.Timeout.persistent_request
3490 How long to wait for the next HTTP request on a persistent
3491 connection after the previous request completes.
3494 NAME: client_lifetime
3497 LOC: Config.Timeout.lifetime
3500 The maximum amount of time a client (browser) is allowed to
3501 remain connected to the cache process. This protects the Cache
3502 from having a lot of sockets (and hence file descriptors) tied up
3503 in a CLOSE_WAIT state from remote clients that go away without
3504 properly shutting down (either because of a network failure or
3505 because of a poor client implementation). The default is one
3508 NOTE: The default value is intended to be much larger than any
3509 client would ever need to be connected to your cache. You
3510 should probably change client_lifetime only as a last resort.
3511 If you seem to have many client connections tying up
3512 filedescriptors, we recommend first tuning the read_timeout,
3513 request_timeout, persistent_request_timeout and quick_abort values.
3516 NAME: half_closed_clients
3518 LOC: Config.onoff.half_closed_clients
3521 Some clients may shutdown the sending side of their TCP
3522 connections, while leaving their receiving sides open. Sometimes,
3523 Squid can not tell the difference between a half-closed and a
3524 fully-closed TCP connection. By default, half-closed client
3525 connections are kept open until a read(2) or write(2) on the
3526 socket returns an error. Change this option to 'off' and Squid
3527 will immediately close client connections when read(2) returns
3528 "no more data to read."
3533 LOC: Config.Timeout.pconn
3536 Timeout for idle persistent connections to servers and other
3543 LOC: Config.Timeout.ident
3546 Maximum time to wait for IDENT lookups to complete.
3548 If this is too high, and you enabled IDENT lookups from untrusted
3549 users, you might be susceptible to denial-of-service by having
3550 many ident requests going at once.
3553 NAME: shutdown_lifetime
3556 LOC: Config.shutdownLifetime
3559 When SIGTERM or SIGHUP is received, the cache is put into
3560 "shutdown pending" mode until all active sockets are closed.
3561 This value is the lifetime to set for all open descriptors
3562 during shutdown mode. Any active clients after this many
3563 seconds will receive a 'timeout' message.
3567 ADMINISTRATIVE PARAMETERS
3568 -----------------------------------------------------------------------------
3574 LOC: Config.adminEmail
3576 Email-address of local cache manager who will receive
3577 mail if the cache dies. The default is "webmaster."
3583 LOC: Config.EmailFrom
3585 From: email-address for mail sent when the cache dies.
3586 The default is to use 'appname@unique_hostname'.
3587 Default appname value is "squid", can be changed into
3588 src/globals.h before building squid.
3594 LOC: Config.EmailProgram
3596 Email program used to send mail if the cache dies.
3597 The default is "mail". The specified program must comply
3598 with the standard Unix mail syntax:
3599 mail-program recipient < mailfile
3601 Optional command line options can be specified.
3604 NAME: cache_effective_user
3606 DEFAULT: @DEFAULT_CACHE_EFFECTIVE_USER@
3607 LOC: Config.effectiveUser
3609 If you start Squid as root, it will change its effective/real
3610 UID/GID to the user specified below. The default is to change
3611 to UID of @DEFAULT_CACHE_EFFECTIVE_USER@.
3612 see also; cache_effective_group
3615 NAME: cache_effective_group
3618 LOC: Config.effectiveGroup
3620 Squid sets the GID to the effective user's default group ID
3621 (taken from the password file) and supplementary group list
3622 from the groups membership.
3624 If you want Squid to run with a specific GID regardless of
3625 the group memberships of the effective user then set this
3626 to the group (or GID) you want Squid to run as. When set
3627 all other group privileges of the effective user are ignored
3628 and only this GID is effective. If Squid is not started as
3629 root the user starting Squid MUST be member of the specified
3632 This option is not recommended by the Squid Team.
3633 Our preference is for administrators to configure a secure
3634 user account for squid with UID/GID matching system policies.
3637 NAME: httpd_suppress_version_string
3641 LOC: Config.onoff.httpd_suppress_version_string
3643 Suppress Squid version string info in HTTP headers and HTML error pages.
3646 NAME: visible_hostname
3648 LOC: Config.visibleHostname
3651 If you want to present a special hostname in error messages, etc,
3652 define this. Otherwise, the return value of gethostname()
3653 will be used. If you have multiple caches in a cluster and
3654 get errors about IP-forwarding you must set them to have individual
3655 names with this setting.
3658 NAME: unique_hostname
3660 LOC: Config.uniqueHostname
3663 If you want to have multiple machines with the same
3664 'visible_hostname' you must give each machine a different
3665 'unique_hostname' so forwarding loops can be detected.
3668 NAME: hostname_aliases
3670 LOC: Config.hostnameAliases
3673 A list of other DNS names your cache has.
3681 Minimum umask which should be enforced while the proxy
3682 is running, in addition to the umask set at startup.
3684 For a traditional octal representation of umasks, start
3689 OPTIONS FOR THE CACHE REGISTRATION SERVICE
3690 -----------------------------------------------------------------------------
3692 This section contains parameters for the (optional) cache
3693 announcement service. This service is provided to help
3694 cache administrators locate one another in order to join or
3695 create cache hierarchies.
3697 An 'announcement' message is sent (via UDP) to the registration
3698 service by Squid. By default, the announcement message is NOT
3699 SENT unless you enable it with 'announce_period' below.
3701 The announcement message includes your hostname, plus the
3702 following information from this configuration file:
3708 All current information is processed regularly and made
3709 available on the Web at http://www.ircache.net/Cache/Tracker/.
3712 NAME: announce_period
3714 LOC: Config.Announce.period
3717 This is how frequently to send cache announcements. The
3718 default is `0' which disables sending the announcement
3721 To enable announcing your cache, just uncomment the line
3725 #To enable announcing your cache, just uncomment the line below.
3726 #announce_period 1 day
3732 DEFAULT: tracker.ircache.net
3733 LOC: Config.Announce.host
3739 LOC: Config.Announce.file
3745 LOC: Config.Announce.port
3747 announce_host and announce_port set the hostname and port
3748 number where the registration message will be sent.
3750 Hostname will default to 'tracker.ircache.net' and port will
3751 default default to 3131. If the 'filename' argument is given,
3752 the contents of that file will be included in the announce
3757 HTTPD-ACCELERATOR OPTIONS
3758 -----------------------------------------------------------------------------
3761 NAME: httpd_accel_surrogate_id
3762 IFDEF: USE_SQUID_ESI
3764 LOC: Config.Accel.surrogate_id
3767 Surrogates (http://www.esi.org/architecture_spec_1.0.html)
3768 need an identification token to allow control targeting. Because
3769 a farm of surrogates may all perform the same tasks, they may share
3770 an identification token.
3773 NAME: http_accel_surrogate_remote
3774 IFDEF: USE_SQUID_ESI
3778 LOC: Config.onoff.surrogate_is_remote
3780 Remote surrogates (such as those in a CDN) honour Surrogate-Control: no-store-remote.
3781 Set this to on to have squid behave as a remote surrogate.
3785 IFDEF: USE_SQUID_ESI
3786 COMMENT: libxml2|expat|custom
3788 LOC: ESIParser::Type
3791 ESI markup is not strictly XML compatible. The custom ESI parser
3792 will give higher performance, but cannot handle non ASCII character
3797 DELAY POOL PARAMETERS
3798 -----------------------------------------------------------------------------
3802 TYPE: delay_pool_count
3807 This represents the number of delay pools to be used. For example,
3808 if you have one class 2 delay pool and one class 3 delays pool, you
3809 have a total of 2 delay pools.
3813 TYPE: delay_pool_class
3818 This defines the class of each delay pool. There must be exactly one
3819 delay_class line for each delay pool. For example, to define two
3820 delay pools, one of class 2 and one of class 3, the settings above
3824 delay_pools 4 # 4 delay pools
3825 delay_class 1 2 # pool 1 is a class 2 pool
3826 delay_class 2 3 # pool 2 is a class 3 pool
3827 delay_class 3 4 # pool 3 is a class 4 pool
3828 delay_class 4 5 # pool 4 is a class 5 pool
3830 The delay pool classes are:
3832 class 1 Everything is limited by a single aggregate
3835 class 2 Everything is limited by a single aggregate
3836 bucket as well as an "individual" bucket chosen
3837 from bits 25 through 32 of the IP address.
3839 class 3 Everything is limited by a single aggregate
3840 bucket as well as a "network" bucket chosen
3841 from bits 17 through 24 of the IP address and a
3842 "individual" bucket chosen from bits 17 through
3843 32 of the IP address.
3845 class 4 Everything in a class 3 delay pool, with an
3846 additional limit on a per user basis. This
3847 only takes effect if the username is established
3848 in advance - by forcing authentication in your
3851 class 5 Requests are grouped according their tag (see
3852 external_acl's tag= reply).
3854 NOTE: If an IP address is a.b.c.d
3855 -> bits 25 through 32 are "d"
3856 -> bits 17 through 24 are "c"
3857 -> bits 17 through 32 are "c * 256 + d"
3861 TYPE: delay_pool_access
3866 This is used to determine which delay pool a request falls into.
3868 delay_access is sorted per pool and the matching starts with pool 1,
3869 then pool 2, ..., and finally pool N. The first delay pool where the
3870 request is allowed is selected for the request. If it does not allow
3871 the request to any pool then the request is not delayed (default).
3873 For example, if you want some_big_clients in delay
3874 pool 1 and lotsa_little_clients in delay pool 2:
3877 delay_access 1 allow some_big_clients
3878 delay_access 1 deny all
3879 delay_access 2 allow lotsa_little_clients
3880 delay_access 2 deny all
3881 delay_access 3 allow authenticated_clients
3884 NAME: delay_parameters
3885 TYPE: delay_pool_rates
3890 This defines the parameters for a delay pool. Each delay pool has
3891 a number of "buckets" associated with it, as explained in the
3892 description of delay_class. For a class 1 delay pool, the syntax is:
3894 delay_parameters pool aggregate
3896 For a class 2 delay pool:
3898 delay_parameters pool aggregate individual
3900 For a class 3 delay pool:
3902 delay_parameters pool aggregate network individual
3904 For a class 4 delay pool:
3906 delay_parameters pool aggregate network individual user
3908 For a class 5 delay pool:
3910 delay_parameters pool tag
3912 The variables here are:
3914 pool a pool number - ie, a number between 1 and the
3915 number specified in delay_pools as used in
3918 aggregate the "delay parameters" for the aggregate bucket
3921 individual the "delay parameters" for the individual
3922 buckets (class 2, 3).
3924 network the "delay parameters" for the network buckets
3927 user the delay parameters for the user buckets
3930 tag the delay parameters for the tag buckets
3933 A pair of delay parameters is written restore/maximum, where restore is
3934 the number of bytes (not bits - modem and network speeds are usually
3935 quoted in bits) per second placed into the bucket, and maximum is the
3936 maximum number of bytes which can be in the bucket at any time.
3938 For example, if delay pool number 1 is a class 2 delay pool as in the
3939 above example, and is being used to strictly limit each host to 64kbps
3940 (plus overheads), with no overall limit, the line is:
3942 delay_parameters 1 -1/-1 8000/8000
3944 Note that the figure -1 is used to represent "unlimited".
3946 And, if delay pool number 2 is a class 3 delay pool as in the above
3947 example, and you want to limit it to a total of 256kbps (strict limit)
3948 with each 8-bit network permitted 64kbps (strict limit) and each
3949 individual host permitted 4800bps with a bucket maximum size of 64kb
3950 to permit a decent web page to be downloaded at a decent speed
3951 (if the network is not being limited due to overuse) but slow down
3952 large downloads more significantly:
3954 delay_parameters 2 32000/32000 8000/8000 600/8000
3956 There must be one delay_parameters line for each delay pool.
3958 Finally, for a class 4 delay pool as in the example - each user will
3959 be limited to 128Kb no matter how many workstations they are logged into.:
3961 delay_parameters 4 32000/32000 8000/8000 600/64000 16000/16000
3964 NAME: delay_initial_bucket_level
3965 COMMENT: (percent, 0-100)
3969 LOC: Config.Delay.initial
3971 The initial bucket percentage is used to determine how much is put
3972 in each bucket when squid starts, is reconfigured, or first notices
3973 a host accessing it (in class 2 and class 3, individual hosts and
3974 networks only have buckets associated with them once they have been
3979 WCCPv1 AND WCCPv2 CONFIGURATION OPTIONS
3980 -----------------------------------------------------------------------------
3985 LOC: Config.Wccp.router
3989 Use this option to define your WCCP ``home'' router for
3992 wccp_router supports a single WCCP(v1) router
3994 wccp2_router supports multiple WCCPv2 routers
3996 only one of the two may be used at the same time and defines
3997 which version of WCCP to use.
4001 TYPE: IPAddress_list
4002 LOC: Config.Wccp2.router
4006 Use this option to define your WCCP ``home'' router for
4009 wccp_router supports a single WCCP(v1) router
4011 wccp2_router supports multiple WCCPv2 routers
4013 only one of the two may be used at the same time and defines
4014 which version of WCCP to use.
4019 LOC: Config.Wccp.version
4023 This directive is only relevant if you need to set up WCCP(v1)
4024 to some very old and end-of-life Cisco routers. In all other
4025 setups it must be left unset or at the default setting.
4026 It defines an internal version in the WCCP(v1) protocol,
4027 with version 4 being the officially documented protocol.
4029 According to some users, Cisco IOS 11.2 and earlier only
4030 support WCCP version 3. If you're using that or an earlier
4031 version of IOS, you may need to change this value to 3, otherwise
4032 do not specify this parameter.
4035 NAME: wccp2_rebuild_wait
4037 LOC: Config.Wccp2.rebuildwait
4041 If this is enabled Squid will wait for the cache dir rebuild to finish
4042 before sending the first wccp2 HereIAm packet
4045 NAME: wccp2_forwarding_method
4047 LOC: Config.Wccp2.forwarding_method
4051 WCCP2 allows the setting of forwarding methods between the
4052 router/switch and the cache. Valid values are as follows:
4054 gre - GRE encapsulation (forward the packet in a GRE/WCCP tunnel)
4055 l2 - L2 redirect (forward the packet using Layer 2/MAC rewriting)
4057 Currently (as of IOS 12.4) cisco routers only support GRE.
4058 Cisco switches only support the L2 redirect assignment method.
4061 NAME: wccp2_return_method
4063 LOC: Config.Wccp2.return_method
4067 WCCP2 allows the setting of return methods between the
4068 router/switch and the cache for packets that the cache
4069 decides not to handle. Valid values are as follows:
4071 gre - GRE encapsulation (forward the packet in a GRE/WCCP tunnel)
4072 l2 - L2 redirect (forward the packet using Layer 2/MAC rewriting)
4074 Currently (as of IOS 12.4) cisco routers only support GRE.
4075 Cisco switches only support the L2 redirect assignment.
4077 If the "ip wccp redirect exclude in" command has been
4078 enabled on the cache interface, then it is still safe for
4079 the proxy server to use a l2 redirect method even if this
4080 option is set to GRE.
4083 NAME: wccp2_assignment_method
4085 LOC: Config.Wccp2.assignment_method
4089 WCCP2 allows the setting of methods to assign the WCCP hash
4090 Valid values are as follows:
4092 hash - Hash assignment
4093 mask - Mask assignment
4095 As a general rule, cisco routers support the hash assignment method
4096 and cisco switches support the mask assignment method.
4101 LOC: Config.Wccp2.info
4103 DEFAULT_IF_NONE: standard 0
4106 WCCP2 allows for multiple traffic services. There are two
4107 types: "standard" and "dynamic". The standard type defines
4108 one service id - http (id 0). The dynamic service ids can be from
4109 51 to 255 inclusive. In order to use a dynamic service id
4110 one must define the type of traffic to be redirected; this is done
4111 using the wccp2_service_info option.
4113 The "standard" type does not require a wccp2_service_info option,
4114 just specifying the service id will suffice.
4116 MD5 service authentication can be enabled by adding
4117 "password=<password>" to the end of this service declaration.
4121 wccp2_service standard 0 # for the 'web-cache' standard service
4122 wccp2_service dynamic 80 # a dynamic service type which will be
4123 # fleshed out with subsequent options.
4124 wccp2_service standard 0 password=foo
4127 NAME: wccp2_service_info
4128 TYPE: wccp2_service_info
4129 LOC: Config.Wccp2.info
4133 Dynamic WCCPv2 services require further information to define the
4134 traffic you wish to have diverted.
4138 wccp2_service_info <id> protocol=<protocol> flags=<flag>,<flag>..
4139 priority=<priority> ports=<port>,<port>..
4141 The relevant WCCPv2 flags:
4142 + src_ip_hash, dst_ip_hash
4143 + source_port_hash, dst_port_hash
4144 + src_ip_alt_hash, dst_ip_alt_hash
4145 + src_port_alt_hash, dst_port_alt_hash
4148 The port list can be one to eight entries.
4152 wccp2_service_info 80 protocol=tcp flags=src_ip_hash,ports_source
4153 priority=240 ports=80
4155 Note: the service id must have been defined by a previous
4156 'wccp2_service dynamic <id>' entry.
4161 LOC: Config.Wccp2.weight
4165 Each cache server gets assigned a set of the destination
4166 hash proportional to their weight.
4171 LOC: Config.Wccp.address
4178 LOC: Config.Wccp2.address
4182 Use this option if you require WCCP to use a specific
4185 The default behavior is to not bind to any specific address.
4189 PERSISTENT CONNECTION HANDLING
4190 -----------------------------------------------------------------------------
4192 Also see "pconn_timeout" in the TIMEOUTS section
4195 NAME: client_persistent_connections
4197 LOC: Config.onoff.client_pconns
4201 NAME: server_persistent_connections
4203 LOC: Config.onoff.server_pconns
4206 Persistent connection support for clients and servers. By
4207 default, Squid uses persistent connections (when allowed)
4208 with its clients and servers. You can use these options to
4209 disable persistent connections with clients and/or servers.
4212 NAME: persistent_connection_after_error
4214 LOC: Config.onoff.error_pconns
4217 With this directive the use of persistent connections after
4218 HTTP errors can be disabled. Useful if you have clients
4219 who fail to handle errors on persistent connections proper.
4222 NAME: detect_broken_pconn
4224 LOC: Config.onoff.detect_broken_server_pconns
4227 Some servers have been found to incorrectly signal the use
4228 of HTTP/1.0 persistent connections even on replies not
4229 compatible, causing significant delays. This server problem
4230 has mostly been seen on redirects.
4232 By enabling this directive Squid attempts to detect such
4233 broken replies and automatically assume the reply is finished
4234 after 10 seconds timeout.
4238 CACHE DIGEST OPTIONS
4239 -----------------------------------------------------------------------------
4242 NAME: digest_generation
4243 IFDEF: USE_CACHE_DIGESTS
4245 LOC: Config.onoff.digest_generation
4248 This controls whether the server will generate a Cache Digest
4249 of its contents. By default, Cache Digest generation is
4250 enabled if Squid is compiled with --enable-cache-digests defined.
4253 NAME: digest_bits_per_entry
4254 IFDEF: USE_CACHE_DIGESTS
4256 LOC: Config.digest.bits_per_entry
4259 This is the number of bits of the server's Cache Digest which
4260 will be associated with the Digest entry for a given HTTP
4261 Method and URL (public key) combination. The default is 5.
4264 NAME: digest_rebuild_period
4265 IFDEF: USE_CACHE_DIGESTS
4268 LOC: Config.digest.rebuild_period
4271 This is the wait time between Cache Digest rebuilds.
4274 NAME: digest_rewrite_period
4276 IFDEF: USE_CACHE_DIGESTS
4278 LOC: Config.digest.rewrite_period
4281 This is the wait time between Cache Digest writes to
4285 NAME: digest_swapout_chunk_size
4288 IFDEF: USE_CACHE_DIGESTS
4289 LOC: Config.digest.swapout_chunk_size
4292 This is the number of bytes of the Cache Digest to write to
4293 disk at a time. It defaults to 4096 bytes (4KB), the Squid
4297 NAME: digest_rebuild_chunk_percentage
4298 COMMENT: (percent, 0-100)
4299 IFDEF: USE_CACHE_DIGESTS
4301 LOC: Config.digest.rebuild_chunk_percentage
4304 This is the percentage of the Cache Digest to be scanned at a
4305 time. By default it is set to 10% of the Cache Digest.
4310 -----------------------------------------------------------------------------
4315 LOC: Config.Port.snmp
4319 The port number where Squid listens for SNMP requests. To enable
4320 SNMP support set this to a suitable port number. Port number
4321 3401 is often used for the Squid SNMP agent. By default it's
4322 set to "0" (disabled)
4330 LOC: Config.accessList.snmp
4332 DEFAULT_IF_NONE: deny all
4335 Allowing or denying access to the SNMP port.
4337 All access to the agent is denied by default.
4340 snmp_access allow|deny [!]aclname ...
4343 snmp_access allow snmppublic localhost
4344 snmp_access deny all
4347 NAME: snmp_incoming_address
4349 LOC: Config.Addrs.snmp_incoming
4354 NAME: snmp_outgoing_address
4356 LOC: Config.Addrs.snmp_outgoing
4357 DEFAULT: 255.255.255.255
4360 Just like 'udp_incoming_address', but for the SNMP port.
4362 snmp_incoming_address is used for the SNMP socket receiving
4363 messages from SNMP agents.
4364 snmp_outgoing_address is used for SNMP packets returned to SNMP
4367 The default snmp_incoming_address (0.0.0.0) is to listen on all
4368 available network interfaces.
4370 If snmp_outgoing_address is set to 255.255.255.255 (the default)
4371 it will use the same socket as snmp_incoming_address. Only
4372 change this if you want to have SNMP replies sent using another
4373 address than where this Squid listens for SNMP queries.
4375 NOTE, snmp_incoming_address and snmp_outgoing_address can not have
4376 the same value since they both use port 3401.
4381 -----------------------------------------------------------------------------
4384 NAME: icp_port udp_port
4387 LOC: Config.Port.icp
4389 The port number where Squid sends and receives ICP queries to
4390 and from neighbor caches. The standard UDP port for ICP is 3130.
4391 Default is disabled (0).
4393 #icp_port @DEFAULT_ICP_PORT@
4401 LOC: Config.Port.htcp
4403 The port number where Squid sends and receives HTCP queries to
4404 and from neighbor caches. To turn it on you want to set it to
4405 4827. By default it is set to "0" (disabled).
4411 NAME: log_icp_queries
4415 LOC: Config.onoff.log_udp
4417 If set, ICP queries are logged to access.log. You may wish
4418 do disable this if your ICP load is VERY high to speed things
4419 up or to simplify log analysis.
4422 NAME: udp_incoming_address
4424 LOC:Config.Addrs.udp_incoming
4427 udp_incoming_address is used for UDP packets received from other
4430 The default behavior is to not bind to any specific address.
4432 Only change this if you want to have all UDP queries received on
4433 a specific interface/address.
4435 NOTE: udp_incoming_address is used by the ICP, HTCP, and DNS
4436 modules. Altering it will affect all of them in the same manner.
4438 see also; udp_outgoing_address
4440 NOTE, udp_incoming_address and udp_outgoing_address can not
4441 have the same value since they both use the same port.
4444 NAME: udp_outgoing_address
4446 LOC: Config.Addrs.udp_outgoing
4447 DEFAULT: 255.255.255.255
4449 udp_outgoing_address is used for UDP packets sent out to other
4452 The default behavior is to not bind to any specific address.
4454 Instead it will use the same socket as udp_incoming_address.
4455 Only change this if you want to have UDP queries sent using another
4456 address than where this Squid listens for UDP queries from other
4459 NOTE: udp_outgoing_address is used by the ICP, HTCP, and DNS
4460 modules. Altering it will affect all of them in the same manner.
4462 see also; udp_incoming_address
4464 NOTE, udp_incoming_address and udp_outgoing_address can not
4465 have the same value since they both use the same port.
4472 LOC: Config.onoff.icp_hit_stale
4474 If you want to return ICP_HIT for stale cache objects, set this
4475 option to 'on'. If you have sibling relationships with caches
4476 in other administrative domains, this should be 'off'. If you only
4477 have sibling relationships with caches under your control,
4478 it is probably okay to set this to 'on'.
4479 If set to 'on', your siblings should use the option "allow-miss"
4480 on their cache_peer lines for connecting to you.
4483 NAME: minimum_direct_hops
4486 LOC: Config.minDirectHops
4488 If using the ICMP pinging stuff, do direct fetches for sites
4489 which are no more than this many hops away.
4492 NAME: minimum_direct_rtt
4495 LOC: Config.minDirectRtt
4497 If using the ICMP pinging stuff, do direct fetches for sites
4498 which are no more than this many rtt milliseconds away.
4504 LOC: Config.Netdb.low
4510 LOC: Config.Netdb.high
4512 The low and high water marks for the ICMP measurement
4513 database. These are counts, not percents. The defaults are
4514 900 and 1000. When the high water mark is reached, database
4515 entries will be deleted until the low mark is reached.
4518 NAME: netdb_ping_period
4520 LOC: Config.Netdb.period
4523 The minimum period for measuring a site. There will be at
4524 least this much delay between successive pings to the same
4525 network. The default is five minutes.
4532 LOC: Config.onoff.query_icmp
4534 If you want to ask your peers to include ICMP data in their ICP
4535 replies, enable this option.
4537 If your peer has configured Squid (during compilation) with
4538 '--enable-icmp' that peer will send ICMP pings to origin server
4539 sites of the URLs it receives. If you enable this option the
4540 ICP replies from that peer will include the ICMP data (if available).
4541 Then, when choosing a parent cache, Squid will choose the parent with
4542 the minimal RTT to the origin server. When this happens, the
4543 hierarchy field of the access.log will be
4544 "CLOSEST_PARENT_MISS". This option is off by default.
4547 NAME: test_reachability
4551 LOC: Config.onoff.test_reachability
4553 When this is 'on', ICP MISS replies will be ICP_MISS_NOFETCH
4554 instead of ICP_MISS if the target host is NOT in the ICMP
4555 database, or has a zero RTT.
4558 NAME: icp_query_timeout
4562 LOC: Config.Timeout.icp_query
4564 Normally Squid will automatically determine an optimal ICP
4565 query timeout value based on the round-trip-time of recent ICP
4566 queries. If you want to override the value determined by
4567 Squid, set this 'icp_query_timeout' to a non-zero value. This
4568 value is specified in MILLISECONDS, so, to use a 2-second
4569 timeout (the old default), you would write:
4571 icp_query_timeout 2000
4574 NAME: maximum_icp_query_timeout
4578 LOC: Config.Timeout.icp_query_max
4580 Normally the ICP query timeout is determined dynamically. But
4581 sometimes it can lead to very large values (say 5 seconds).
4582 Use this option to put an upper limit on the dynamic timeout
4583 value. Do NOT use this option to always use a fixed (instead
4584 of a dynamic) timeout value. To set a fixed timeout see the
4585 'icp_query_timeout' directive.
4588 NAME: minimum_icp_query_timeout
4592 LOC: Config.Timeout.icp_query_min
4594 Normally the ICP query timeout is determined dynamically. But
4595 sometimes it can lead to very small timeouts, even lower than
4596 the normal latency variance on your link due to traffic.
4597 Use this option to put an lower limit on the dynamic timeout
4598 value. Do NOT use this option to always use a fixed (instead
4599 of a dynamic) timeout value. To set a fixed timeout see the
4600 'icp_query_timeout' directive.
4603 NAME: background_ping_rate
4607 LOC: Config.backgroundPingRate
4609 Controls how often the ICP pings are sent to siblings that
4610 have background-ping set.
4614 MULTICAST ICP OPTIONS
4615 -----------------------------------------------------------------------------
4620 LOC: Config.mcast_group_list
4623 This tag specifies a list of multicast groups which your server
4624 should join to receive multicasted ICP queries.
4626 NOTE! Be very careful what you put here! Be sure you
4627 understand the difference between an ICP _query_ and an ICP
4628 _reply_. This option is to be set only if you want to RECEIVE
4629 multicast queries. Do NOT set this option to SEND multicast
4630 ICP (use cache_peer for that). ICP replies are always sent via
4631 unicast, so this option does not affect whether or not you will
4632 receive replies from multicast group members.
4634 You must be very careful to NOT use a multicast address which
4635 is already in use by another group of caches.
4637 If you are unsure about multicast, please read the Multicast
4638 chapter in the Squid FAQ (http://www.squid-cache.org/FAQ/).
4640 Usage: mcast_groups 239.128.16.128 224.0.1.20
4642 By default, Squid doesn't listen on any multicast groups.
4645 NAME: mcast_miss_addr
4646 IFDEF: MULTICAST_MISS_STREAM
4648 LOC: Config.mcast_miss.addr
4649 DEFAULT: 255.255.255.255
4651 If you enable this option, every "cache miss" URL will
4652 be sent out on the specified multicast address.
4654 Do not enable this option unless you are are absolutely
4655 certain you understand what you are doing.
4658 NAME: mcast_miss_ttl
4659 IFDEF: MULTICAST_MISS_STREAM
4661 LOC: Config.mcast_miss.ttl
4664 This is the time-to-live value for packets multicasted
4665 when multicasting off cache miss URLs is enabled. By
4666 default this is set to 'site scope', i.e. 16.
4669 NAME: mcast_miss_port
4670 IFDEF: MULTICAST_MISS_STREAM
4672 LOC: Config.mcast_miss.port
4675 This is the port number to be used in conjunction with
4679 NAME: mcast_miss_encode_key
4680 IFDEF: MULTICAST_MISS_STREAM
4682 LOC: Config.mcast_miss.encode_key
4683 DEFAULT: XXXXXXXXXXXXXXXX
4685 The URLs that are sent in the multicast miss stream are
4686 encrypted. This is the encryption key.
4689 NAME: mcast_icp_query_timeout
4693 LOC: Config.Timeout.mcast_icp_query
4695 For multicast peers, Squid regularly sends out ICP "probes" to
4696 count how many other peers are listening on the given multicast
4697 address. This value specifies how long Squid should wait to
4698 count all the replies. The default is 2000 msec, or 2
4703 INTERNAL ICON OPTIONS
4704 -----------------------------------------------------------------------------
4707 NAME: icon_directory
4709 LOC: Config.icons.directory
4710 DEFAULT: @DEFAULT_ICON_DIR@
4712 Where the icons are stored. These are normally kept in
4716 NAME: global_internal_static
4718 LOC: Config.onoff.global_internal_static
4721 This directive controls is Squid should intercept all requests for
4722 /squid-internal-static/ no matter which host the URL is requesting
4723 (default on setting), or if nothing special should be done for
4724 such URLs (off setting). The purpose of this directive is to make
4725 icons etc work better in complex cache hierarchies where it may
4726 not always be possible for all corners in the cache mesh to reach
4727 the server generating a directory listing.
4730 NAME: short_icon_urls
4732 LOC: Config.icons.use_short_names
4735 If this is enabled Squid will use short URLs for icons.
4736 If disabled it will revert to the old behavior of including
4737 it's own name and port in the URL.
4739 If you run a complex cache hierarchy with a mix of Squid and
4740 other proxies you may need to disable this directive.
4745 -----------------------------------------------------------------------------
4748 NAME: error_directory
4750 LOC: Config.errorDirectory
4753 If you wish to create your own versions of the default
4754 error files to customize them to suit your company copy
4755 the error/template files to another directory and point
4758 WARNING: This option will disable multi-language support
4759 on error pages if used.
4761 The squid developers are interested in making squid available in
4762 a wide variety of languages. If you are making translations for a
4763 language that Squid does not currently provide please consider
4764 contributing your translation back to the project.
4765 http://wiki.squid-cache.org/Translations
4767 The squid developers working on translations are happy to supply drop-in
4768 translated error files in exchange for any new language contributions.
4771 NAME: error_default_language
4772 IFDEF: USE_ERR_LOCALES
4774 LOC: Config.errorDefaultLanguage
4777 Set the default language which squid will send error pages in
4778 if no existing translation matches the clients language
4781 If unset (default) generic English will be used.
4783 The squid developers are interested in making squid available in
4784 a wide variety of languages. If you are interested in making
4785 translations for any language see the squid wiki for details.
4786 http://wiki.squid-cache.org/Translations
4791 LOC: Config.errHtmlText
4794 HTML text to include in error messages. Make this a "mailto"
4795 URL to your admin address, or maybe just a link to your
4796 organizations Web page.
4798 To include this in your error messages, you must rewrite
4799 the error template files (found in the "errors" directory).
4800 Wherever you want the 'err_html_text' line to appear,
4801 insert a %L tag in the error template file.
4804 NAME: email_err_data
4807 LOC: Config.onoff.emailErrData
4810 If enabled, information about the occurred error will be
4811 included in the mailto links of the ERR pages (if %W is set)
4812 so that the email body contains the data.
4813 Syntax is <A HREF="mailto:%w%W">%w</A>
4818 LOC: Config.denyInfoList
4821 Usage: deny_info err_page_name acl
4822 or deny_info http://... acl
4823 or deny_info TCP_RESET acl
4825 This can be used to return a ERR_ page for requests which
4826 do not pass the 'http_access' rules. Squid remembers the last
4827 acl it evaluated in http_access, and if a 'deny_info' line exists
4828 for that ACL Squid returns a corresponding error page.
4830 The acl is typically the last acl on the http_access deny line which
4831 denied access. The exceptions to this rule are:
4832 - When Squid needs to request authentication credentials. It's then
4833 the first authentication related acl encountered
4834 - When none of the http_access lines matches. It's then the last
4835 acl processed on the last http_access line.
4837 NP: If providing your own custom error pages with error_directory
4838 you may also specify them by your custom file name:
4839 Example: deny_info ERR_CUSTOM_ACCESS_DENIED bad_guys
4841 Alternatively you can specify an error URL. The browsers will
4842 get redirected (302) to the specified URL. %s in the redirection
4843 URL will be replaced by the requested URL.
4845 Alternatively you can tell Squid to reset the TCP connection
4846 by specifying TCP_RESET.
4850 OPTIONS INFLUENCING REQUEST FORWARDING
4851 -----------------------------------------------------------------------------
4854 NAME: nonhierarchical_direct
4856 LOC: Config.onoff.nonhierarchical_direct
4859 By default, Squid will send any non-hierarchical requests
4860 (matching hierarchy_stoplist or not cacheable request type) direct
4863 If you set this to off, Squid will prefer to send these
4864 requests to parents.
4866 Note that in most configurations, by turning this off you will only
4867 add latency to these request without any improvement in global hit
4870 If you are inside an firewall see never_direct instead of
4876 LOC: Config.onoff.prefer_direct
4879 Normally Squid tries to use parents for most requests. If you for some
4880 reason like it to first try going direct and only use a parent if
4881 going direct fails set this to on.
4883 By combining nonhierarchical_direct off and prefer_direct on you
4884 can set up Squid to use a parent as a backup path if going direct
4887 Note: If you want Squid to use parents for all requests see
4888 the never_direct directive. prefer_direct only modifies how Squid
4889 acts on cacheable requests.
4894 LOC: Config.accessList.AlwaysDirect
4897 Usage: always_direct allow|deny [!]aclname ...
4899 Here you can use ACL elements to specify requests which should
4900 ALWAYS be forwarded by Squid to the origin servers without using
4901 any peers. For example, to always directly forward requests for
4902 local servers ignoring any parents or siblings you may have use
4905 acl local-servers dstdomain my.domain.net
4906 always_direct allow local-servers
4908 To always forward FTP requests directly, use
4911 always_direct allow FTP
4913 NOTE: There is a similar, but opposite option named
4914 'never_direct'. You need to be aware that "always_direct deny
4915 foo" is NOT the same thing as "never_direct allow foo". You
4916 may need to use a deny rule to exclude a more-specific case of
4917 some other rule. Example:
4919 acl local-external dstdomain external.foo.net
4920 acl local-servers dstdomain .foo.net
4921 always_direct deny local-external
4922 always_direct allow local-servers
4924 NOTE: If your goal is to make the client forward the request
4925 directly to the origin server bypassing Squid then this needs
4926 to be done in the client configuration. Squid configuration
4927 can only tell Squid how Squid should fetch the object.
4929 NOTE: This directive is not related to caching. The replies
4930 is cached as usual even if you use always_direct. To not cache
4931 the replies see no_cache.
4933 This option replaces some v1.1 options such as local_domain
4939 LOC: Config.accessList.NeverDirect
4942 Usage: never_direct allow|deny [!]aclname ...
4944 never_direct is the opposite of always_direct. Please read
4945 the description for always_direct if you have not already.
4947 With 'never_direct' you can use ACL elements to specify
4948 requests which should NEVER be forwarded directly to origin
4949 servers. For example, to force the use of a proxy for all
4950 requests, except those in your local domain use something like:
4952 acl local-servers dstdomain .foo.net
4953 never_direct deny local-servers
4954 never_direct allow all
4956 or if Squid is inside a firewall and there are local intranet
4957 servers inside the firewall use something like:
4959 acl local-intranet dstdomain .foo.net
4960 acl local-external dstdomain external.foo.net
4961 always_direct deny local-external
4962 always_direct allow local-intranet
4963 never_direct allow all
4965 This option replaces some v1.1 options such as inside_firewall
4970 ADVANCED NETWORKING OPTIONS
4971 -----------------------------------------------------------------------------
4974 NAME: incoming_icp_average
4977 LOC: Config.comm_incoming.icp_average
4980 NAME: incoming_http_average
4983 LOC: Config.comm_incoming.http_average
4986 NAME: incoming_dns_average
4989 LOC: Config.comm_incoming.dns_average
4992 NAME: min_icp_poll_cnt
4995 LOC: Config.comm_incoming.icp_min_poll
4998 NAME: min_dns_poll_cnt
5001 LOC: Config.comm_incoming.dns_min_poll
5004 NAME: min_http_poll_cnt
5007 LOC: Config.comm_incoming.http_min_poll
5009 Heavy voodoo here. I can't even believe you are reading this.
5010 Are you crazy? Don't even think about adjusting these unless
5011 you understand the algorithms in comm_select.c first!
5017 LOC: Config.accept_filter
5021 The name of an accept(2) filter to install on Squid's
5022 listen socket(s). This feature is perhaps specific to
5023 FreeBSD and requires support in the kernel.
5025 The 'httpready' filter delays delivering new connections
5026 to Squid until a full HTTP request has been received.
5027 See the accf_http(9) man page for details.
5029 The 'dataready' filter delays delivering new connections
5030 to Squid until there is some data to process.
5031 See the accf_dataready(9) man page for details.
5035 The 'data' filter delays delivering of new connections
5036 to Squid until there is some data to process by TCP_ACCEPT_DEFER.
5037 You may optionally specify a number of seconds to wait by
5038 'data=N' where N is the number of seconds. Defaults to 30
5039 if not specified. See the tcp(7) man page for details.
5042 accept_filter httpready
5047 NAME: tcp_recv_bufsize
5051 LOC: Config.tcpRcvBufsz
5053 Size of receive buffer to set for TCP sockets. Probably just
5054 as easy to change your kernel's default. Set to zero to use
5055 the default buffer size.
5060 -----------------------------------------------------------------------------
5067 LOC: TheICAPConfig.onoff
5070 If you want to enable the ICAP module support, set this to on.
5073 NAME: icap_connect_timeout
5076 LOC: TheICAPConfig.connect_timeout_raw
5079 This parameter specifies how long to wait for the TCP connect to
5080 the requested ICAP server to complete before giving up and either
5081 terminating the HTTP transaction or bypassing the failure.
5083 The default for optional services is peer_connect_timeout.
5084 The default for essential services is connect_timeout.
5085 If this option is explicitly set, its value applies to all services.
5088 NAME: icap_io_timeout
5092 LOC: TheICAPConfig.io_timeout_raw
5095 This parameter specifies how long to wait for an I/O activity on
5096 an established, active ICAP connection before giving up and
5097 either terminating the HTTP transaction or bypassing the
5100 The default is read_timeout.
5103 NAME: icap_service_failure_limit
5106 LOC: TheICAPConfig.service_failure_limit
5109 The limit specifies the number of failures that Squid tolerates
5110 when establishing a new TCP connection with an ICAP service. If
5111 the number of failures exceeds the limit, the ICAP service is
5112 not used for new ICAP requests until it is time to refresh its
5113 OPTIONS. The per-service failure counter is reset to zero each
5114 time Squid fetches new service OPTIONS.
5116 A negative value disables the limit. Without the limit, an ICAP
5117 service will not be considered down due to connectivity failures
5118 between ICAP OPTIONS requests.
5121 NAME: icap_service_revival_delay
5124 LOC: TheICAPConfig.service_revival_delay
5127 The delay specifies the number of seconds to wait after an ICAP
5128 OPTIONS request failure before requesting the options again. The
5129 failed ICAP service is considered "down" until fresh OPTIONS are
5132 The actual delay cannot be smaller than the hardcoded minimum
5133 delay of 30 seconds.
5136 NAME: icap_preview_enable
5140 LOC: TheICAPConfig.preview_enable
5143 The ICAP Preview feature allows the ICAP server to handle the
5144 HTTP message by looking only at the beginning of the message body
5145 or even without receiving the body at all. In some environments,
5146 previews greatly speedup ICAP processing.
5148 During an ICAP OPTIONS transaction, the server may tell Squid what
5149 HTTP messages should be previewed and how big the preview should be.
5150 Squid will not use Preview if the server did not request one.
5152 To disable ICAP Preview for all ICAP services, regardless of
5153 individual ICAP server OPTIONS responses, set this option to "off".
5155 icap_preview_enable off
5158 NAME: icap_preview_size
5161 LOC: TheICAPConfig.preview_size
5164 The default size of preview data to be sent to the ICAP server.
5165 -1 means no preview. This value might be overwritten on a per server
5166 basis by OPTIONS requests.
5169 NAME: icap_default_options_ttl
5172 LOC: TheICAPConfig.default_options_ttl
5175 The default TTL value for ICAP OPTIONS responses that don't have
5176 an Options-TTL header.
5179 NAME: icap_persistent_connections
5183 LOC: TheICAPConfig.reuse_connections
5186 Whether or not Squid should use persistent connections to
5190 NAME: icap_send_client_ip
5194 LOC: TheICAPConfig.send_client_ip
5197 This adds the header "X-Client-IP" to ICAP requests.
5200 NAME: icap_send_client_username
5204 LOC: TheICAPConfig.send_client_username
5207 This sends authenticated HTTP client username (if available) to
5208 the ICAP service. The username value is encoded based on the
5209 icap_client_username_encode option and is sent using the header
5210 specified by the icap_client_username_header option.
5213 NAME: icap_client_username_header
5216 LOC: TheICAPConfig.client_username_header
5217 DEFAULT: X-Client-Username
5219 ICAP request header name to use for send_client_username.
5222 NAME: icap_client_username_encode
5226 LOC: TheICAPConfig.client_username_encode
5229 Whether to base64 encode the authenticated client username.
5233 TYPE: icap_service_type
5238 Defines a single ICAP service
5240 icap_service servicename vectoring_point bypass service_url
5242 vectoring_point = reqmod_precache|reqmod_postcache|respmod_precache|respmod_postcache
5243 This specifies at which point of transaction processing the
5244 ICAP service should be activated. *_postcache vectoring points
5245 are not yet supported.
5247 If set to 1, the ICAP service is treated as optional. If the
5248 service cannot be reached or malfunctions, Squid will try to
5249 ignore any errors and process the message as if the service
5250 was not enabled. No all ICAP errors can be bypassed.
5251 If set to 0, the ICAP service is treated as essential and all
5252 ICAP errors will result in an error page returned to the
5254 service_url = icap://servername:port/service
5257 icap_service service_1 reqmod_precache 0 icap://icap1.mydomain.net:1344/reqmod
5258 icap_service service_2 respmod_precache 0 icap://icap2.mydomain.net:1344/respmod
5262 TYPE: icap_class_type
5267 This depricated option was documented to define an ICAP service
5268 chain, even though it actually defined a set of similar, redundant
5269 services, and the chains were not supported.
5271 To define a set of redundant services, please use the
5272 adaptation_service_set directive.
5274 If you need adaptation service chains, patches or sponsorship
5279 TYPE: icap_access_type
5284 This option is depricated. Please use adaptation_access, which
5285 has the same ICAP functionality, but comes with better
5286 documentation, and eCAP support.
5291 -----------------------------------------------------------------------------
5294 NAME: loadable_modules
5296 IFDEF: USE_LOADABLE_MODULES
5297 LOC: Config.loadable_module_names
5300 Instructs Squid to load the specified dynamic module(s) or activate
5301 preloaded module(s).
5303 loadable_modules @DEFAULT_PREFIX@/lib/MinimalAdapter.so
5307 MESSAGE ADAPTATION OPTIONS
5308 -----------------------------------------------------------------------------
5311 NAME: adaptation_service_set
5312 TYPE: adaptation_service_set_type
5313 IFDEF: USE_ADAPTATION
5318 Defines a named adaptation service set. The set is populated in
5319 the order of adaptation_service_set directives in this file.
5320 When adaptation ACLs are processed, the first and only the first
5321 applicable adaptation service from the set will be used. Thus,
5322 the set should group similar, redundant services, rather than a
5323 chain of complementary services.
5325 If you have a single adaptation service, you do not need to
5326 define a set containing it because adaptation_access accepts
5329 See also: adaptation_access
5332 adaptation_service_set svcBlocker urlFilterPrimary urlFilterBackup
5333 adaptation service_set svcLogger loggerLocal loggerRemote
5336 NAME: adaptation_access
5337 TYPE: adaptation_access_type
5338 IFDEF: USE_ADAPTATION
5342 Sends an HTTP transaction to an ICAP or eCAP adaptation service.
5344 adaptation_access service_name allow|deny [!]aclname...
5345 adaptation_access set_name allow|deny [!]aclname...
5347 At each supported vectoring point, the adaptation_access
5348 statements are processed in the order they appear in this
5349 configuration file. Statements pointing to the following services
5350 are ignored (i.e., skipped without checking their ACL):
5352 - services serving different vectoring points
5353 - "broken-but-bypassable" services
5354 - "up" services configured to ignore such transactions
5355 (e.g., based on the ICAP Transfer-Ignore header).
5357 When a set_name is used, all services in the set are checked
5358 using the same rules, to find the first applicable one. See
5359 adaptation_service_set for details.
5361 If an access list is checked and there is a match, the
5362 processing stops: For an "allow" rule, the corresponding
5363 adaptation service is used for the transaction. For a "deny"
5364 rule, no adaptation service is activated.
5366 It is currently not possible to apply more than one adaptation
5367 service at the same vectoring point to the same HTTP transaction.
5369 See also: icap_service and ecap_service
5372 adaptation_access service_1 allow all
5377 -----------------------------------------------------------------------------
5380 NAME: check_hostnames
5383 LOC: Config.onoff.check_hostnames
5385 For security and stability reasons Squid can check
5386 hostnames for Internet standard RFC compliance. If you want
5387 Squid to perform these checks turn this directive on.
5390 NAME: allow_underscore
5393 LOC: Config.onoff.allow_underscore
5395 Underscore characters is not strictly allowed in Internet hostnames
5396 but nevertheless used by many sites. Set this to off if you want
5397 Squid to be strict about the standard.
5398 This check is performed only when check_hostnames is set to on.
5401 NAME: cache_dns_program
5403 IFDEF: USE_DNSSERVERS
5404 DEFAULT: @DEFAULT_DNSSERVER@
5405 LOC: Config.Program.dnsserver
5407 Specify the location of the executable for dnslookup process.
5412 IFDEF: USE_DNSSERVERS
5414 LOC: Config.dnsChildren
5416 The number of processes spawn to service DNS name lookups.
5417 For heavily loaded caches on large servers, you should
5418 probably increase this value to at least 10. The maximum
5419 is 32. The default is 5.
5421 You must have at least one dnsserver process.
5424 NAME: dns_retransmit_interval
5427 LOC: Config.Timeout.idns_retransmit
5428 IFDEF: !USE_DNSSERVERS
5430 Initial retransmit interval for DNS queries. The interval is
5431 doubled each time all configured DNS servers have been tried.
5438 LOC: Config.Timeout.idns_query
5439 IFDEF: !USE_DNSSERVERS
5441 DNS Query timeout. If no response is received to a DNS query
5442 within this time all DNS servers for the queried domain
5443 are assumed to be unavailable.
5450 LOC: Config.onoff.res_defnames
5452 Normally the RES_DEFNAMES resolver option is disabled
5453 (see res_init(3)). This prevents caches in a hierarchy
5454 from interpreting single-component hostnames locally. To allow
5455 Squid to handle single-component names, enable this option.
5458 NAME: dns_nameservers
5461 LOC: Config.dns_nameservers
5463 Use this if you want to specify a list of DNS name servers
5464 (IP addresses) to use instead of those given in your
5465 /etc/resolv.conf file.
5466 On Windows platforms, if no value is specified here or in
5467 the /etc/resolv.conf file, the list of DNS name servers are
5468 taken from the Windows registry, both static and dynamic DHCP
5469 configurations are supported.
5471 Example: dns_nameservers 10.0.0.1 192.172.0.4
5476 DEFAULT: @DEFAULT_HOSTS@
5477 LOC: Config.etcHostsPath
5479 Location of the host-local IP name-address associations
5480 database. Most Operating Systems have such a file on different
5482 - Un*X & Linux: /etc/hosts
5483 - Windows NT/2000: %SystemRoot%\system32\drivers\etc\hosts
5484 (%SystemRoot% value install default is c:\winnt)
5485 - Windows XP/2003: %SystemRoot%\system32\drivers\etc\hosts
5486 (%SystemRoot% value install default is c:\windows)
5487 - Windows 9x/Me: %windir%\hosts
5488 (%windir% value is usually c:\windows)
5489 - Cygwin: /etc/hosts
5491 The file contains newline-separated definitions, in the
5492 form ip_address_in_dotted_form name [name ...] names are
5493 whitespace-separated. Lines beginning with an hash (#)
5494 character are comments.
5496 The file is checked at startup and upon configuration.
5497 If set to 'none', it won't be checked.
5498 If append_domain is used, that domain will be added to
5499 domain-local (i.e. not containing any dot character) host
5505 LOC: Config.appendDomain
5508 Appends local domain name to hostnames without any dots in
5509 them. append_domain must begin with a period.
5511 Be warned there are now Internet names with no dots in
5512 them using only top-domain names, so setting this may
5513 cause some Internet sites to become unavailable.
5516 append_domain .yourdomain.com
5519 NAME: ignore_unknown_nameservers
5521 LOC: Config.onoff.ignore_unknown_nameservers
5524 By default Squid checks that DNS responses are received
5525 from the same IP addresses they are sent to. If they
5526 don't match, Squid ignores the response and writes a warning
5527 message to cache.log. You can allow responses from unknown
5528 nameservers by setting this option to 'off'.
5531 NAME: dns_v4_fallback
5534 LOC: Config.onoff.dns_require_A
5536 Standard practice with DNS is to lookup either A or AAAA records
5537 and use the results if it succeeds. Only looking up the other if
5538 the first attempt fails or otherwise produces no results.
5540 That policy however will cause squid to produce error pages for some
5541 servers that advertise AAAA but are unreachable over IPv6.
5543 If this is ON squid will always lookup both AAAA and A, using both.
5544 If this is OFF squid will lookup AAAA and only try A if none found.
5546 WARNING: There are some possibly unwanted side-effects with this on:
5547 *) Doubles the load placed by squid on the DNS network.
5548 *) May negatively impact connection delay times.
5552 COMMENT: (number of entries)
5555 LOC: Config.ipcache.size
5562 LOC: Config.ipcache.low
5569 LOC: Config.ipcache.high
5571 The size, low-, and high-water marks for the IP cache.
5574 NAME: fqdncache_size
5575 COMMENT: (number of entries)
5578 LOC: Config.fqdncache.size
5580 Maximum number of FQDN cache entries.
5585 -----------------------------------------------------------------------------
5592 LOC: Config.onoff.mem_pools
5594 If set, Squid will keep pools of allocated (but unused) memory
5595 available for future use. If memory is a premium on your
5596 system and you believe your malloc library outperforms Squid
5597 routines, disable this.
5600 NAME: memory_pools_limit
5604 LOC: Config.MemPools.limit
5606 Used only with memory_pools on:
5607 memory_pools_limit 50 MB
5609 If set to a non-zero value, Squid will keep at most the specified
5610 limit of allocated (but unused) memory in memory pools. All free()
5611 requests that exceed this limit will be handled by your malloc
5612 library. Squid does not pre-allocate any memory, just safe-keeps
5613 objects that otherwise would be free()d. Thus, it is safe to set
5614 memory_pools_limit to a reasonably high value even if your
5615 configuration will use less memory.
5617 If set to zero, Squid will keep all memory it can. That is, there
5618 will be no limit on the total amount of memory used for safe-keeping.
5620 To disable memory allocation optimization, do not set
5621 memory_pools_limit to 0. Set memory_pools to "off" instead.
5623 An overhead for maintaining memory pools is not taken into account
5624 when the limit is checked. This overhead is close to four bytes per
5625 object kept. However, pools may actually _save_ memory because of
5626 reduced memory thrashing in your malloc library.
5630 COMMENT: on|off|transparent|truncate|delete
5633 LOC: opt_forwarded_for
5635 If set to "on", Squid will append your client's IP address
5636 in the HTTP requests it forwards. By default it looks like:
5638 X-Forwarded-For: 192.1.2.3
5640 If set to "off", it will appear as
5642 X-Forwarded-For: unknown
5644 If set to "transparent", Squid will not alter the
5645 X-Forwarded-For header in any way.
5647 If set to "delete", Squid will delete the entire
5648 X-Forwarded-For header.
5650 If set to "truncate", Squid will remove all existing
5651 X-Forwarded-For entries, and place itself as the sole entry.
5654 NAME: cachemgr_passwd
5655 TYPE: cachemgrpasswd
5657 LOC: Config.passwd_list
5659 Specify passwords for cachemgr operations.
5661 Usage: cachemgr_passwd password action action ...
5663 Some valid actions are (see cache manager menu for a full list):
5703 * Indicates actions which will not be performed without a
5704 valid password, others can be performed if not listed here.
5706 To disable an action, set the password to "disable".
5707 To allow performing an action without a password, set the
5710 Use the keyword "all" to set the same password for all actions.
5713 cachemgr_passwd secret shutdown
5714 cachemgr_passwd lesssssssecret info stats/objects
5715 cachemgr_passwd disable all
5722 LOC: Config.onoff.client_db
5724 If you want to disable collecting per-client statistics,
5725 turn off client_db here.
5728 NAME: refresh_all_ims
5732 LOC: Config.onoff.refresh_all_ims
5734 When you enable this option, squid will always check
5735 the origin server for an update when a client sends an
5736 If-Modified-Since request. Many browsers use IMS
5737 requests when the user requests a reload, and this
5738 ensures those clients receive the latest version.
5740 By default (off), squid may return a Not Modified response
5741 based on the age of the cached version.
5744 NAME: reload_into_ims
5745 IFDEF: HTTP_VIOLATIONS
5749 LOC: Config.onoff.reload_into_ims
5751 When you enable this option, client no-cache or ``reload''
5752 requests will be changed to If-Modified-Since requests.
5753 Doing this VIOLATES the HTTP standard. Enabling this
5754 feature could make you liable for problems which it
5757 see also refresh_pattern for a more selective approach.
5760 NAME: maximum_single_addr_tries
5762 LOC: Config.retry.maxtries
5765 This sets the maximum number of connection attempts for a
5766 host that only has one address (for multiple-address hosts,
5767 each address is tried once).
5769 The default value is one attempt, the (not recommended)
5770 maximum is 255 tries. A warning message will be generated
5771 if it is set to a value greater than ten.
5773 Note: This is in addition to the request re-forwarding which
5774 takes place if Squid fails to get a satisfying response.
5777 NAME: retry_on_error
5779 LOC: Config.retry.onerror
5782 If set to on Squid will automatically retry requests when
5783 receiving an error response. This is mainly useful if you
5784 are in a complex cache hierarchy to work around access
5788 NAME: as_whois_server
5790 LOC: Config.as_whois_server
5791 DEFAULT: whois.ra.net
5792 DEFAULT_IF_NONE: whois.ra.net
5794 WHOIS server to query for AS numbers. NOTE: AS numbers are
5795 queried only when Squid starts up, not for every request.
5800 LOC: Config.onoff.offline
5803 Enable this option and Squid will never try to validate cached
5807 NAME: uri_whitespace
5808 TYPE: uri_whitespace
5809 LOC: Config.uri_whitespace
5812 What to do with requests that have whitespace characters in the
5815 strip: The whitespace characters are stripped out of the URL.
5816 This is the behavior recommended by RFC2396.
5817 deny: The request is denied. The user receives an "Invalid
5819 allow: The request is allowed and the URI is not changed. The
5820 whitespace characters remain in the URI. Note the
5821 whitespace is passed to redirector processes if they
5823 encode: The request is allowed and the whitespace characters are
5824 encoded according to RFC1738. This could be considered
5825 a violation of the HTTP/1.1
5826 RFC because proxies are not allowed to rewrite URI's.
5827 chop: The request is allowed and the URI is chopped at the
5828 first whitespace. This might also be considered a
5834 LOC: Config.coredump_dir
5836 DEFAULT_IF_NONE: none
5838 By default Squid leaves core files in the directory from where
5839 it was started. If you set 'coredump_dir' to a directory
5840 that exists, Squid will chdir() to that directory at startup
5841 and coredump files will be left there.
5844 # Leave coredumps in the first cache dir
5845 coredump_dir @DEFAULT_SWAP_DIR@
5851 LOC: Config.chroot_dir
5854 Use this to have Squid do a chroot() while initializing. This
5855 also causes Squid to fully drop root privileges after
5856 initializing. This means, for example, if you use a HTTP
5857 port less than 1024 and try to reconfigure, you will may get an
5858 error saying that Squid can not open the port.
5861 NAME: balance_on_multiple_ip
5863 LOC: Config.onoff.balance_on_multiple_ip
5866 Modern IP resolvers in squid sort lookup results by preferred access.
5867 By default squid will use these IP in order and only rotates to
5868 the next listed when the most preffered fails.
5870 Some load balancing servers based on round robin DNS have been
5871 found not to preserve user session state across requests
5872 to different IP addresses.
5874 Enabling this directive Squid rotates IP's per request.
5877 NAME: pipeline_prefetch
5879 LOC: Config.onoff.pipeline_prefetch
5882 To boost the performance of pipelined requests to closer
5883 match that of a non-proxied environment Squid can try to fetch
5884 up to two requests in parallel from a pipeline.
5886 Defaults to off for bandwidth management and access logging
5890 NAME: high_response_time_warning
5893 LOC: Config.warnings.high_rptm
5896 If the one-minute median response time exceeds this value,
5897 Squid prints a WARNING with debug level 0 to get the
5898 administrators attention. The value is in milliseconds.
5901 NAME: high_page_fault_warning
5903 LOC: Config.warnings.high_pf
5906 If the one-minute average page fault rate exceeds this
5907 value, Squid prints a WARNING with debug level 0 to get
5908 the administrators attention. The value is in page faults
5912 NAME: high_memory_warning
5914 LOC: Config.warnings.high_memory
5917 If the memory usage (as determined by mallinfo) exceeds
5918 this amount, Squid prints a WARNING with debug level 0 to get
5919 the administrators attention.
5922 NAME: sleep_after_fork
5923 COMMENT: (microseconds)
5925 LOC: Config.sleep_after_fork
5928 When this is set to a non-zero value, the main Squid process
5929 sleeps the specified number of microseconds after a fork()
5930 system call. This sleep may help the situation where your
5931 system reports fork() failures due to lack of (virtual)
5932 memory. Note, however, if you have a lot of child
5933 processes, these sleep delays will add up and your
5934 Squid will not service requests for some amount of time
5935 until all the child processes have been started.
5936 On Windows value less then 1000 (1 milliseconds) are
5940 NAME: windows_ipaddrchangemonitor
5944 LOC: Config.onoff.WIN32_IpAddrChangeMonitor
5946 On Windows Squid by default will monitor IP address changes and will
5947 reconfigure itself after any detected event. This is very useful for
5948 proxies connected to internet with dial-up interfaces.
5949 In some cases (a Proxy server acting as VPN gateway is one) it could be
5950 desiderable to disable this behaviour setting this to 'off'.
5951 Note: after changing this, Squid service must be restarted.