3 # $Id: cf.data.pre,v 1.408 2005/12/01 23:23:59 wessels Exp $
6 # SQUID Web Proxy Cache http://www.squid-cache.org/
7 # ----------------------------------------------------------
9 # Squid is the result of efforts by numerous individuals from
10 # the Internet community; see the CONTRIBUTORS file for full
11 # details. Many organizations have provided support for Squid's
12 # development; see the SPONSORS file for full details. Squid is
13 # Copyrighted (C) 2000 by the Regents of the University of
14 # California; see the COPYRIGHT file for full details. Squid
15 # incorporates software developed and/or copyrighted by other
16 # sources; see the CREDITS file for full details.
18 # This program is free software; you can redistribute it and/or modify
19 # it under the terms of the GNU General Public License as published by
20 # the Free Software Foundation; either version 2 of the License, or
21 # (at your option) any later version.
23 # This program is distributed in the hope that it will be useful,
24 # but WITHOUT ANY WARRANTY; without even the implied warranty of
25 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
26 # GNU General Public License for more details.
28 # You should have received a copy of the GNU General Public License
29 # along with this program; if not, write to the Free Software
30 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
34 WELCOME TO SQUID @VERSION@
35 ----------------------------
37 This is the default Squid configuration file. You may wish
38 to look at the Squid home page (http://www.squid-cache.org/)
39 for the FAQ and other documentation.
41 The default Squid config file shows what the defaults for
42 various options happen to be. If you don't need to change the
43 default, you shouldn't uncomment the line. Doing so may cause
44 run-time problems. In some cases "none" refers to no default
45 setting at all, while in other cases it refers to a valid
46 option - the comments for that keyword indicate if this is the
53 -----------------------------------------------------------------------------
56 NAME: http_port ascii_port
59 LOC: Config.Sockaddr.http
62 hostname:port [options]
63 1.2.3.4:port [options]
65 The socket addresses where Squid will listen for HTTP client
66 requests. You may specify multiple socket addresses.
67 There are three forms: port alone, hostname with port, and
68 IP address with port. If you specify a hostname or IP
69 address, Squid binds the socket to that specific
70 address. This replaces the old 'tcp_incoming_address'
71 option. Most likely, you do not need to bind to a specific
72 address, so you can use the port number alone.
74 If you are running Squid in accelerator mode, you
75 probably want to listen on port 80 also, or instead.
77 The -a command line option will override the *first* port
78 number listed here. That option will NOT override an IP
81 You may specify multiple socket addresses on multiple lines.
85 transparent Support for transparent proxies
87 accel Accelerator mode. Also set implicit by the other
88 accelerator directives
90 vhost Accelerator mode using Host header for virtual
93 vport Accelerator with IP based virtual host support
95 vport=NN As above, but uses specified port number rather
96 than the http_port number
98 defaultsite= Main web site name for accelerators
100 protocol= Protocol to reconstruct accelerated requests with.
103 disable-pmtu-discovery=
104 Control Path-MTU discovery usage:
105 off lets OS decide on what to do (default).
106 transparent disable PMTU discovery when transparent
108 always disable always PMTU discovery.
110 In many setups of transparently intercepting proxies Path-MTU
111 discovery can not work on traffic towards the clients. This is
112 the case when the intercepting device does not fully track
113 connections and fails to forward ICMP must fragment messages
114 to the cache server. If you have such setup and experience that
115 certain clients sporadically hang or never complete requests set
116 disable-pmtu-discovery option to 'transparent'.
118 If you run Squid on a dual-homed machine with an internal
119 and an external interface we recommend you to specify the
120 internal address:port in http_port. This way Squid will only be
121 visible on the internal address.
123 # Squid normally listens to port 3128
124 http_port @DEFAULT_HTTP_PORT@
130 TYPE: https_port_list
132 LOC: Config.Sockaddr.https
134 Usage: [ip:]port cert=certificate.pem [key=key.pem] [options...]
136 The socket address where Squid will listen for HTTPS client
139 This is really only useful for situations where you are running
140 squid in accelerator mode and you want to do the SSL work at the
143 You may specify multiple socket addresses on multiple lines,
144 each with their own SSL certificate and/or options.
148 defaultsite= The name of the https site presented on
151 protocol= Protocol to reconstruct accelerated requests
152 with. Defaults to https
154 cert= Path to SSL certificate (PEM format)
156 key= Path to SSL private key file (PEM format)
157 if not specified, the certificate file is
158 assumed to be a combined certificate and
161 version= The version of SSL/TLS supported
162 1 automatic (default)
167 cipher= Colon separated list of supported ciphers
169 options= Various SSL engine options. The most important
171 NO_SSLv2 Disallow the use of SSLv2
172 NO_SSLv3 Disallow the use of SSLv3
173 NO_TLSv1 Disallow the use of TLSv1
174 SINGLE_DH_USE Always create a new key when using
175 temporary/ephemeral DH key exchanges
176 See src/ssl_support.c or OpenSSL SSL_CTX_set_options
177 documentation for a complete list of options
179 clientca= File containing the list of CAs to use when
180 requesting a client certificate
182 cafile= File containing additional CA certificates to
183 use when verifying client certificates. If unset
184 clientca will be used
186 capath= Directory containing additional CA certificates
187 and CRL lists to use when verifying client certificates
189 crlfile= File of additional CRL lists to use when verifying
190 the client certificate, in addition to CRLs stored in
191 the capath. Implies VERIFY_CRL flag below.
193 dhparams= File containing DH parameters for temporary/ephemeral
196 sslflags= Various flags modifying the use of SSL:
198 Don't request client certificates
199 immediately, but wait until acl processing
200 requires a certificate (not yet implemented)
202 Don't use the default CA lists built in
205 Don't allow for session reuse. Each connection
206 will result in a new SSL session.
208 Verify CRL lists when accepting client
211 Verify CRL lists for all certificates in the
212 client certificate chain
214 sslcontext= SSL session ID context identifier.
216 accel Accelerator mode. Also set implicit by the other
217 accelerator directives
219 vhost Accelerator mode using Host header for virtual
222 vport Accelerator with IP based virtual host support
224 vport=NN As above, but uses specified port number rather
225 than the https_port number
229 NAME: ssl_unclean_shutdown
233 LOC: Config.SSL.unclean_shutdown
235 Some browsers (especially MSIE) bugs out on SSL shutdown
242 LOC: Config.SSL.ssl_engine
245 The openssl engine to use. You will need to set this if you
246 would like to use hardware SSL acceleration for example.
249 NAME: sslproxy_client_certificate
252 LOC: Config.ssl_client.cert
255 Client SSL Certificate to use when proxying https:// URLs
258 NAME: sslproxy_client_key
261 LOC: Config.ssl_client.key
264 Client SSL Key to use when proxying https:// URLs
267 NAME: sslproxy_version
270 LOC: Config.ssl_client.version
273 SSL version level to use when proxying https:// URLs
276 NAME: sslproxy_options
279 LOC: Config.ssl_client.options
282 SSL engine options to use when proxying https:// URLs
285 NAME: sslproxy_cipher
288 LOC: Config.ssl_client.cipher
291 SSL cipher list to use when proxying https:// URLs
294 NAME: sslproxy_cafile
297 LOC: Config.ssl_client.cafile
300 file containing CA certificates to use when verifying server
301 certificates while proxying https:// URLs
304 NAME: sslproxy_capath
307 LOC: Config.ssl_client.capath
310 directory containing CA certificates to use when verifying
311 server certificates while proxying https:// URLs
317 LOC: Config.ssl_client.flags
320 Various flags modifying the use of SSL while proxying https:// URLs:
321 DONT_VERIFY_PEER Accept certificates even if they fail to
323 NO_DEFAULT_CA Don't use the default CA list built in
327 NAME: sslpassword_program
330 LOC: Config.Program.ssl_password
333 Specify a program used for entering SSL key passphrases
334 when using encrypted SSL certificate keys. If not specified
335 keys must either be unencrypted, or Squid started with the -N
336 option to allow it to query interactively for the passphrase.
339 NAME: icp_port udp_port
344 The port number where Squid sends and receives ICP queries to
345 and from neighbor caches. The standard UDP port for ICP is 3130.
346 Default is disabled (0).
348 icp_port @DEFAULT_ICP_PORT@
356 LOC: Config.Port.htcp
358 The port number where Squid sends and receives HTCP queries to
359 and from neighbor caches. Default is 4827. To disable use
366 LOC: Config.mcast_group_list
369 This tag specifies a list of multicast groups which your server
370 should join to receive multicasted ICP queries.
372 NOTE! Be very careful what you put here! Be sure you
373 understand the difference between an ICP _query_ and an ICP
374 _reply_. This option is to be set only if you want to RECEIVE
375 multicast queries. Do NOT set this option to SEND multicast
376 ICP (use cache_peer for that). ICP replies are always sent via
377 unicast, so this option does not affect whether or not you will
378 receive replies from multicast group members.
380 You must be very careful to NOT use a multicast address which
381 is already in use by another group of caches.
383 If you are unsure about multicast, please read the Multicast
384 chapter in the Squid FAQ (http://www.squid-cache.org/FAQ/).
386 Usage: mcast_groups 239.128.16.128 224.0.1.20
388 By default, Squid doesn't listen on any multicast groups.
392 NAME: udp_incoming_address
394 LOC:Config.Addrs.udp_incoming
398 NAME: udp_outgoing_address
400 LOC: Config.Addrs.udp_outgoing
401 DEFAULT: 255.255.255.255
403 udp_incoming_address is used for the ICP socket receiving packets
405 udp_outgoing_address is used for ICP packets sent out to other
408 The default behavior is to not bind to any specific address.
410 A udp_incoming_address value of 0.0.0.0 indicates Squid
411 should listen for UDP messages on all available interfaces.
413 If udp_outgoing_address is set to 255.255.255.255 (the default)
414 it will use the same socket as udp_incoming_address. Only
415 change this if you want to have ICP queries sent using another
416 address than where this Squid listens for ICP queries from other
419 NOTE, udp_incoming_address and udp_outgoing_address can not
420 have the same value since they both use port 3130.
424 OPTIONS WHICH AFFECT THE NEIGHBOR SELECTION ALGORITHM
425 -----------------------------------------------------------------------------
433 To specify other caches in a hierarchy, use the format:
435 cache_peer hostname type http_port icp_port [options]
440 # hostname type port port options
441 # -------------------- -------- ----- ----- -----------
442 cache_peer parent.foo.net parent 3128 3130 [proxy-only]
443 cache_peer sib1.foo.net sibling 3128 3130 [proxy-only]
444 cache_peer sib2.foo.net sibling 3128 3130 [proxy-only]
446 type: either 'parent', 'sibling', or 'multicast'.
448 proxy_port: The port number where the cache listens for proxy
451 icp_port: Used for querying neighbor caches about
452 objects. To have a non-ICP neighbor
453 specify '7' for the ICP port and make sure the
454 neighbor machine has the UDP echo port
455 enabled in its /etc/inetd.conf file.
472 login=user:password | PASS | *:password
482 sslcert=/path/to/ssl/certificate
483 sslkey=/path/to/ssl/key
487 front-end-https[=on|auto]
489 use 'proxy-only' to specify objects fetched
490 from this cache should not be saved locally.
492 use 'weight=n' to specify a weighted parent.
493 The weight must be an integer. The default weight
494 is 1, larger weights are favored more.
496 use 'basetime=n' to specify a base amount to
497 be subtracted from round trip times of parents.
498 It is subtracted before division by weight in calculating
499 which parent to fectch from. If the rtt is less than the
500 base time the rtt is set to a minimal value.
502 use 'ttl=n' to specify a IP multicast TTL to use
503 when sending an ICP queries to this address.
504 Only useful when sending to a multicast group.
505 Because we don't accept ICP replies from random
506 hosts, you must configure other group members as
507 peers with the 'multicast-responder' option below.
509 use 'no-query' to NOT send ICP queries to this
512 use 'background-ping' to only send ICP queries to this
513 neighbor infrequently. This is used to keep the neighbor
514 round trip time updated and is usually used in
515 conjunction with weighted-round-robin.
517 use 'default' if this is a parent cache which can
518 be used as a "last-resort." You should probably
519 only use 'default' in situations where you cannot
520 use ICP with your parent cache(s).
522 use 'round-robin' to define a set of parents which
523 should be used in a round-robin fashion in the
524 absence of any ICP queries.
526 use 'weighted-round-robin' to define a set of parents
527 which should be used in a round-robin fashion with the
528 frequency of each parent being based on the round trip
529 time. Closer parents are used more often.
530 Usually used for background-ping parents.
532 use 'carp' to define a set of parents which should
533 be used as a CARP array. The requests will be
534 distributed among the parents based on the CARP load
535 balancing hash function based on their weigth.
537 'multicast-responder' indicates the named peer
538 is a member of a multicast group. ICP queries will
539 not be sent directly to the peer, but ICP replies
540 will be accepted from it.
542 'closest-only' indicates that, for ICP_OP_MISS
543 replies, we'll only forward CLOSEST_PARENT_MISSes
544 and never FIRST_PARENT_MISSes.
546 use 'no-digest' to NOT request cache digests from
549 'no-netdb-exchange' disables requesting ICMP
550 RTT database (NetDB) from the neighbor.
552 use 'no-delay' to prevent access to this neighbor
553 from influencing the delay pools.
555 use 'login=user:password' if this is a personal/workgroup
556 proxy and your parent requires proxy authentication.
557 Note: The string can include URL escapes (i.e. %20 for
558 spaces). This also means % must be written as %%.
560 use 'login=PASS' if users must authenticate against
561 the upstream proxy or in the case of a reverse proxy
562 configuration, the origin web server. This will pass
563 the users credentials as they are to the peer.
564 This only works for the Basic HTTP authentication scheme.
565 Note: To combine this with proxy_auth both proxies must
566 share the same user database as HTTP only allows for
568 Also be warned this will expose your users proxy
569 password to the peer. USE WITH CAUTION
571 use 'login=*:password' to pass the username to the
572 upstream cache, but with a fixed password. This is meant
573 to be used when the peer is in another administrative
574 domain, but it is still needed to identify each user.
575 The star can optionally be followed by some extra
576 information which is added to the username. This can
577 be used to identify this proxy to the peer, similar to
578 the login=username:password option above.
580 use 'connect-timeout=nn' to specify a peer
581 specific connect timeout (also see the
582 peer_connect_timeout directive)
584 use 'digest-url=url' to tell Squid to fetch the cache
585 digest (if digests are enabled) for this host from
586 the specified URL rather than the Squid default
589 use 'allow-miss' to disable Squid's use of only-if-cached
590 when forwarding requests to siblings. This is primarily
591 useful when icp_hit_stale is used by the sibling. To
592 extensive use of this option may result in forwarding
593 loops, and you should avoid having two-way peerings
594 with this option. (for example to deny peer usage on
595 requests from peer by denying cache_peer_access if the
598 use 'max-conn' to limit the amount of connections Squid
599 may open to this peer.
601 use 'htcp' to send HTCP, instead of ICP, queries
602 to the neighbor. You probably also want to
603 set the "icp port" to 4827 instead of 3130.
605 'originserver' causes this parent peer to be contacted as
606 a origin server. Meant to be used in accelerator setups.
608 use 'name=xxx' if you have multiple peers on the same
609 host but different ports. This name can be used to
610 differentiate the peers in cache_peer_access and similar
613 use 'forceddomain=name' to forcibly set the Host header
614 of requests forwarded to this peer. Useful in accelerator
615 setups where the server (peer) expects a certain domain
616 name and using redirectors to feed this domainname
619 use 'ssl' to indicate connections to this peer should
620 bs SSL/TLS encrypted.
622 use 'sslcert=/path/to/ssl/certificate' to specify a client
623 SSL certificate to use when connecting to this peer.
625 use 'sslkey=/path/to/ssl/key' to specify the private SSL
626 key corresponding to sslcert above. If 'sslkey' is not
627 specified 'sslcert' is assumed to reference a
628 combined file containing both the certificate and the key.
630 use sslversion=1|2|3|4 to specify the SSL version to use
631 when connecting to this peer
632 1 = automatic (default)
637 use sslcipher=... to specify the list of valid SSL chipers
638 to use when connecting to this peer
640 use ssloptions=... to specify various SSL engine options:
641 NO_SSLv2 Disallow the use of SSLv2
642 NO_SSLv3 Disallow the use of SSLv3
643 NO_TLSv1 Disallow the use of TLSv1
644 See src/ssl_support.c or the OpenSSL documentation for
645 a more complete list.
647 use cafile=... to specify a file containing additional
648 CA certificates to use when verifying the peer certificate
650 use capath=... to specify a directory containing additional
651 CA certificates to use when verifying the peer certificate
653 use sslflags=... to specify various flags modifying the
656 Accept certificates even if they fail to
659 Don't use the default CA list built in
662 Don't verify the peer certificate
663 matches the server name
665 use sslname= to specify the peer name as advertised
666 in it's certificate. Used for verifying the correctness
667 of the received peer certificate. If not specified the
668 peer hostname will be used.
670 use front-end-https to enable the "Front-End-Https: On"
671 header needed when using Squid as a SSL frontend infront
672 of Microsoft OWA. See MS KB document Q307347 for details
673 on this header. If set to auto the header will
674 only be added if the request is forwarded as a https://
677 NOTE: non-ICP neighbors must be specified as 'parent'.
680 NAME: cache_peer_domain cache_host_domain
685 Use to limit the domains for which a neighbor cache will be
688 cache_peer_domain cache-host domain [domain ...]
689 cache_peer_domain cache-host !domain
691 For example, specifying
693 cache_peer_domain parent.foo.net .edu
695 has the effect such that UDP query packets are sent to
696 'bigserver' only when the requested object exists on a
697 server in the .edu domain. Prefixing the domainname
698 with '!' means the cache will be queried for objects
701 NOTE: * Any number of domains may be given for a cache-host,
702 either on the same or separate lines.
703 * When multiple domains are given for a particular
704 cache-host, the first matched domain is applied.
705 * Cache hosts with no domain restrictions are queried
707 * There are no defaults.
708 * There is also a 'cache_peer_access' tag in the ACL
713 NAME: neighbor_type_domain
718 usage: neighbor_type_domain neighbor parent|sibling domain domain ...
720 Modifying the neighbor type for specific domains is now
721 possible. You can treat some domains differently than the the
722 default neighbor type specified on the 'cache_peer' line.
723 Normally it should only be necessary to list domains which
724 should be treated differently because the default neighbor type
725 applies for hostnames which do not match domains listed here.
728 cache_peer parent cache.foo.org 3128 3130
729 neighbor_type_domain cache.foo.org sibling .com .net
730 neighbor_type_domain cache.foo.org sibling .au .de
733 NAME: icp_query_timeout
737 LOC: Config.Timeout.icp_query
739 Normally Squid will automatically determine an optimal ICP
740 query timeout value based on the round-trip-time of recent ICP
741 queries. If you want to override the value determined by
742 Squid, set this 'icp_query_timeout' to a non-zero value. This
743 value is specified in MILLISECONDS, so, to use a 2-second
744 timeout (the old default), you would write:
746 icp_query_timeout 2000
749 NAME: maximum_icp_query_timeout
753 LOC: Config.Timeout.icp_query_max
755 Normally the ICP query timeout is determined dynamically. But
756 sometimes it can lead to very large values (say 5 seconds).
757 Use this option to put an upper limit on the dynamic timeout
758 value. Do NOT use this option to always use a fixed (instead
759 of a dynamic) timeout value. To set a fixed timeout see the
760 'icp_query_timeout' directive.
763 NAME: minimum_icp_query_timeout
767 LOC: Config.Timeout.icp_query_min
769 Normally the ICP query timeout is determined dynamically. But
770 sometimes it can lead to very small timeouts, even lower than
771 the normal latency variance on your link due to traffic.
772 Use this option to put an lower limit on the dynamic timeout
773 value. Do NOT use this option to always use a fixed (instead
774 of a dynamic) timeout value. To set a fixed timeout see the
775 'icp_query_timeout' directive.
778 NAME: mcast_icp_query_timeout
782 LOC: Config.Timeout.mcast_icp_query
784 For Multicast peers, Squid regularly sends out ICP "probes" to
785 count how many other peers are listening on the given multicast
786 address. This value specifies how long Squid should wait to
787 count all the replies. The default is 2000 msec, or 2
791 NAME: dead_peer_timeout
795 LOC: Config.Timeout.deadPeer
797 This controls how long Squid waits to declare a peer cache
798 as "dead." If there are no ICP replies received in this
799 amount of time, Squid will declare the peer dead and not
800 expect to receive any further ICP replies. However, it
801 continues to send ICP queries, and will mark the peer as
802 alive upon receipt of the first subsequent ICP reply.
804 This timeout also affects when Squid expects to receive ICP
805 replies from peers. If more than 'dead_peer' seconds have
806 passed since the last ICP reply was received, Squid will not
807 expect to receive an ICP reply on the next query. Thus, if
808 your time between requests is greater than this timeout, you
809 will see a lot of requests sent DIRECT to origin servers
810 instead of to your parents.
814 NAME: hierarchy_stoplist
817 LOC: Config.hierarchy_stoplist
819 A list of words which, if found in a URL, cause the object to
820 be handled directly by this cache. In other words, use this
821 to not query neighbor caches for certain objects. You may
822 list this option multiple times.
824 #We recommend you to use at least the following line.
825 hierarchy_stoplist cgi-bin ?
833 LOC: Config.accessList.noCache
835 A list of ACL elements which, if matched, cause the request to
836 not be satisfied from the cache and the reply to not be cached.
837 In other words, use this to force certain objects to never be cached.
839 You must use the word 'DENY' to indicate the ACL names which should
843 #We recommend you to use the following two lines.
844 acl QUERY urlpath_regex cgi-bin \?
849 NAME: background_ping_rate
853 LOC: Config.backgroundPingRate
855 Controls how often the ICP pings are sent to siblings that
856 have background-ping set.
861 OPTIONS WHICH AFFECT THE CACHE SIZE
862 -----------------------------------------------------------------------------
869 LOC: Config.memMaxSize
871 NOTE: THIS PARAMETER DOES NOT SPECIFY THE MAXIMUM PROCESS SIZE.
872 IT ONLY PLACES A LIMIT ON HOW MUCH ADDITIONAL MEMORY SQUID WILL
873 USE AS A MEMORY CACHE OF OBJECTS. SQUID USES MEMORY FOR OTHER
874 THINGS AS WELL. SEE THE SQUID FAQ SECTION 8 FOR DETAILS.
876 'cache_mem' specifies the ideal amount of memory to be used
880 * Negative-Cached objects
882 Data for these objects are stored in 4 KB blocks. This
883 parameter specifies the ideal upper limit on the total size of
884 4 KB blocks allocated. In-Transit objects take the highest
887 In-transit objects have priority over the others. When
888 additional space is needed for incoming data, negative-cached
889 and hot objects will be released. In other words, the
890 negative-cached and hot objects will fill up any unused space
891 not needed for in-transit objects.
893 If circumstances require, this limit will be exceeded.
894 Specifically, if your incoming request rate requires more than
895 'cache_mem' of memory to hold in-transit objects, Squid will
896 exceed this limit to satisfy the new requests. When the load
897 decreases, blocks will be freed until the high-water mark is
898 reached. Thereafter, blocks will be used to store hot
904 COMMENT: (percent, 0-100)
907 LOC: Config.Swap.lowWaterMark
910 NAME: cache_swap_high
911 COMMENT: (percent, 0-100)
914 LOC: Config.Swap.highWaterMark
917 The low- and high-water marks for cache object replacement.
918 Replacement begins when the swap (disk) usage is above the
919 low-water mark and attempts to maintain utilization near the
920 low-water mark. As swap utilization gets close to high-water
921 mark object eviction becomes more aggressive. If utilization is
922 close to the low-water mark less replacement is done each time.
924 Defaults are 90% and 95%. If you have a large cache, 5% could be
925 hundreds of MB. If this is the case you may wish to set these
926 numbers closer together.
929 NAME: maximum_object_size
933 LOC: Config.Store.maxObjectSize
935 Objects larger than this size will NOT be saved on disk. The
936 value is specified in kilobytes, and the default is 4MB. If
937 you wish to get a high BYTES hit ratio, you should probably
938 increase this (one 32 MB object hit counts for 3200 10KB
939 hits). If you wish to increase speed more than your want to
940 save bandwidth you should leave this low.
942 NOTE: if using the LFUDA replacement policy you should increase
943 this value to maximize the byte hit rate improvement of LFUDA!
944 See replacement_policy below for a discussion of this policy.
947 NAME: minimum_object_size
951 LOC: Config.Store.minObjectSize
953 Objects smaller than this size will NOT be saved on disk. The
954 value is specified in kilobytes, and the default is 0 KB, which
955 means there is no minimum.
958 NAME: maximum_object_size_in_memory
962 LOC: Config.Store.maxInMemObjSize
964 Objects greater than this size will not be attempted to kept in
965 the memory cache. This should be set high enough to keep objects
966 accessed frequently in memory to improve performance whilst low
967 enough to keep larger objects from hoarding cache_mem .
971 COMMENT: (number of entries)
974 LOC: Config.ipcache.size
981 LOC: Config.ipcache.low
988 LOC: Config.ipcache.high
990 The size, low-, and high-water marks for the IP cache.
994 COMMENT: (number of entries)
997 LOC: Config.fqdncache.size
999 Maximum number of FQDN cache entries.
1002 NAME: cache_replacement_policy
1004 LOC: Config.replPolicy
1007 The cache replacement policy parameter determines which
1008 objects are evicted (replaced) when disk space is needed.
1010 lru : Squid's original list based LRU policy
1011 heap GDSF : Greedy-Dual Size Frequency
1012 heap LFUDA: Least Frequently Used with Dynamic Aging
1013 heap LRU : LRU policy implemented using a heap
1015 Applies to any cache_dir lines listed below this.
1017 The LRU policies keeps recently referenced objects.
1019 The heap GDSF policy optimizes object hit rate by keeping smaller
1020 popular objects in cache so it has a better chance of getting a
1021 hit. It achieves a lower byte hit rate than LFUDA though since
1022 it evicts larger (possibly popular) objects.
1024 The heap LFUDA policy keeps popular objects in cache regardless of
1025 their size and thus optimizes byte hit rate at the expense of
1026 hit rate since one large, popular object will prevent many
1027 smaller, slightly less popular objects from being cached.
1029 Both policies utilize a dynamic aging mechanism that prevents
1030 cache pollution that can otherwise occur with frequency-based
1031 replacement policies.
1033 NOTE: if using the LFUDA replacement policy you should increase
1034 the value of maximum_object_size above its default of 4096 KB to
1035 to maximize the potential byte hit rate improvement of LFUDA.
1037 For more information about the GDSF and LFUDA cache replacement
1038 policies see http://www.hpl.hp.com/techreports/1999/HPL-1999-69.html
1039 and http://fog.hpl.external.hp.com/techreports/98/HPL-98-173.html.
1042 NAME: memory_replacement_policy
1044 LOC: Config.memPolicy
1047 The memory replacement policy parameter determines which
1048 objects are purged from memory when memory space is needed.
1050 See cache_replacement_policy for details.
1055 LOGFILE PATHNAMES AND CACHE DIRECTORIES
1056 -----------------------------------------------------------------------------
1062 DEFAULT_IF_NONE: ufs @DEFAULT_SWAP_DIR@ 100 16 256
1063 LOC: Config.cacheSwap
1067 cache_dir Type Directory-Name Fs-specific-data [options]
1069 You can specify multiple cache_dir lines to spread the
1070 cache among different disk partitions.
1072 Type specifies the kind of storage system to use. Only "ufs"
1073 is built by default. To enable any of the other storage systems
1074 see the --enable-storeio configure option.
1076 'Directory' is a top-level directory where cache swap
1077 files will be stored. If you want to use an entire disk
1078 for caching, this can be the mount-point directory.
1079 The directory must exist and be writable by the Squid
1080 process. Squid will NOT create this directory for you.
1084 "ufs" is the old well-known Squid storage format that has always
1087 cache_dir ufs Directory-Name Mbytes L1 L2 [options]
1089 'Mbytes' is the amount of disk space (MB) to use under this
1090 directory. The default is 100 MB. Change this to suit your
1091 configuration. Do NOT put the size of your disk drive here.
1092 Instead, if you want Squid to use the entire disk drive,
1093 subtract 20% and use that value.
1095 'Level-1' is the number of first-level subdirectories which
1096 will be created under the 'Directory'. The default is 16.
1098 'Level-2' is the number of second-level subdirectories which
1099 will be created under each first-level directory. The default
1102 The aufs store type:
1104 "aufs" uses the same storage format as "ufs", utilizing
1105 POSIX-threads to avoid blocking the main Squid process on
1106 disk-I/O. This was formerly known in Squid as async-io.
1108 cache_dir aufs Directory-Name Mbytes L1 L2 [options]
1110 see argument descriptions under ufs above
1112 The diskd store type:
1114 "diskd" uses the same storage format as "ufs", utilizing a
1115 separate process to avoid blocking the main Squid process on
1118 cache_dir diskd Directory-Name Mbytes L1 L2 [options] [Q1=n] [Q2=n]
1120 see argument descriptions under ufs above
1122 Q1 specifies the number of unacknowledged I/O requests when Squid
1123 stops opening new files. If this many messages are in the queues,
1124 Squid won't open new files. Default is 64
1126 Q2 specifies the number of unacknowledged messages when Squid
1127 starts blocking. If this many messages are in the queues,
1128 Squid blocks until it receives some replies. Default is 72
1130 When Q1 < Q2 (the default), the cache directory is optimized
1131 for lower response time at the expense of a decrease in hit
1132 ratio. If Q1 > Q2, the cache directory is optimized for
1133 higher hit ratio at the expense of an increase in response
1136 The coss store type:
1138 block-size=n defines the "block size" for COSS cache_dir's.
1139 Squid uses file numbers as block numbers. Since file numbers
1140 are limited to 24 bits, the block size determines the maximum
1141 size of the COSS partition. The default is 512 bytes, which
1142 leads to a maximum cache_dir size of 512<<24, or 8 GB. Note
1143 you should not change the coss block size after Squid
1144 has written some objects to the cache_dir.
1146 The coss file store has changed from 2.5. Now it uses a file
1147 called 'stripe' in the directory names in the config - and
1148 this will be created by squid -z.
1152 read-only, this cache_dir is read only.
1154 max-size=n, refers to the max object size this storedir supports.
1155 It is used to initially choose the storedir to dump the object.
1156 Note: To make optimal use of the max-size limits you should order
1157 the cache_dir lines with the smallest max-size value first and the
1158 ones with no max-size specification last.
1160 Note for coss, max-size must be less than COSS_MEMBUF_SZ,
1161 which can be changed with the --with-coss-membuf-size=N configure
1164 The null store type:
1166 no options are allowed or required
1172 LOC: Config.Log.logformats
1177 logformat <name> <format specification>
1179 Defines an access log format.
1181 The <format specification> is a string with embedded % format codes
1183 % format codes all follow the same basic structure where all but
1184 the formatcode is optional. Output strings are automatically escaped
1185 as required according to their context and the output format
1186 modifiers are usually not needed, but can be specified if an explicit
1187 output format is desired.
1189 % ["|[|'|#] [-] [[0]width] [{argument}] formatcode
1191 " output in quoted string format
1192 [ output in squid text log format as used by log_mime_hdrs
1193 # output in URL quoted format
1197 width field width. If starting with 0 the
1198 output is zero padded
1199 {arg} argument such as header name etc
1203 >a Client source IP address
1205 <A Server IP address or peer name
1206 la Local IP address (http_port)
1207 lp Local port number (http_port)
1208 ts Seconds since epoch
1209 tu subsecond time (milliseconds)
1210 tl Local time. Optional strftime format argument
1211 default %d/%b/%Y:%H:%M:S %z
1212 tg GMT time. Optional strftime format argument
1213 default %d/%b/%Y:%H:%M:S %z
1214 tr Response time (milliseconds)
1215 >h Request header. Optional header name argument
1216 on the format header[:[separator]element]
1217 <h Reply header. Optional header name argument
1222 ue User from external acl
1224 Ss Squid request status (TCP_MISS etc)
1225 Sh Squid hierarchy status (DEFAULT_PARENT etc)
1226 mt MIME content type
1227 rm Request method (GET/POST etc)
1229 rv Request protocol version
1230 et Tag returned by external acl
1231 ea Log string returned by external acl
1232 <st Reply size including HTTP headers
1233 <sH Reply high offset sent
1234 <sS Upstream object size
1235 % a literal % character
1237 logformat squid %ts.%03tu %6tr %>a %Ss/%03Hs %<st %rm %ru %un %Sh/%<A %mt
1238 logformat squidmime %ts.%03tu %6tr %>a %Ss/%03Hs %<st %rm %ru %un %Sh/%<A %mt [%>h] [%<h]
1239 logformat common %>a %ui %un [%tl] "%rm %ru HTTP/%rv" %Hs %<st %Ss:%Sh
1240 logformat combined %>a %ui %un [%tl] "%rm %ru HTTP/%rv" %Hs %<st "%{Referer}>h" "%{User-Agent}>h" %Ss:%Sh
1243 NAME: access_log cache_access_log
1245 LOC: Config.Log.accesslogs
1247 DEFAULT_IF_NONE: @DEFAULT_ACCESS_LOG@
1249 These files log client request activities. Has a line every HTTP or
1250 ICP request. The format is:
1251 access_log <filepath> [<logformat name> [acl acl ...]]
1252 access_log none [acl acl ...]]
1254 Will log to the specified file using the specified format (which
1255 must be defined in a logformat directive) those entries which match
1256 ALL the acl's specified (which must be defined in acl clauses).
1257 If no acl is specified, all requests will be logged to this file.
1259 To disable logging of a request use the filepath "none", in which case
1260 a logformat name should not be specified.
1262 To log the request via syslog specify a filepath of "syslog"
1268 DEFAULT: @DEFAULT_CACHE_LOG@
1271 Cache logging file. This is where general information about
1272 your cache's behavior goes. You can increase the amount of data
1273 logged to this file with the "debug_options" tag below.
1277 NAME: cache_store_log
1279 DEFAULT: @DEFAULT_STORE_LOG@
1280 LOC: Config.Log.store
1282 Logs the activities of the storage manager. Shows which
1283 objects are ejected from the cache, and which objects are
1284 saved and for how long. To disable, enter "none". There are
1285 not really utilities to analyze this data, so you can safely
1290 NAME: cache_swap_state cache_swap_log
1292 LOC: Config.Log.swap
1295 Location for the cache "swap.state" file. This index file holds
1296 the metadata of objects saved on disk. It is used to rebuild
1297 the cache during startup. Normally this file resides in each
1298 'cache_dir' directory, but you may specify an alternate
1299 pathname here. Note you must give a full filename, not just
1300 a directory. Since this is the index for the whole object
1301 list you CANNOT periodically rotate it!
1303 If %s can be used in the file name it will be replaced with a
1304 a representation of the cache_dir name where each / is replaced
1305 with '.'. This is needed to allow adding/removing cache_dir
1306 lines when cache_swap_log is being used.
1308 If have more than one 'cache_dir', and %s is not used in the name
1309 these swap logs will have names such as:
1315 The numbered extension (which is added automatically)
1316 corresponds to the order of the 'cache_dir' lines in this
1317 configuration file. If you change the order of the 'cache_dir'
1318 lines in this file, these log files will NOT correspond to
1319 the correct 'cache_dir' entry (unless you manually rename
1320 them). We recommend you do NOT use this option. It is
1321 better to keep these log files in each 'cache_dir' directory.
1325 NAME: emulate_httpd_log
1329 LOC: Config.onoff.common_log
1331 The Cache can emulate the log file format which many 'httpd'
1332 programs use. To disable/enable this emulation, set
1333 emulate_httpd_log to 'off' or 'on'. The default
1334 is to use the native log format since it includes useful
1335 information Squid-specific log analyzers use.
1338 NAME: log_ip_on_direct
1342 LOC: Config.onoff.log_ip_on_direct
1344 Log the destination IP address in the hierarchy log tag when going
1345 direct. Earlier Squid versions logged the hostname here. If you
1346 prefer the old way set this to off.
1351 DEFAULT: @DEFAULT_MIME_TABLE@
1352 LOC: Config.mimeTablePathname
1354 Pathname to Squid's MIME table. You shouldn't need to change
1355 this, but the default file contains examples and formatting
1356 information if you do.
1363 LOC: Config.onoff.log_mime_hdrs
1366 The Cache can record both the request and the response MIME
1367 headers for each HTTP transaction. The headers are encoded
1368 safely and will appear as two bracketed fields at the end of
1369 the access log (for either the native or httpd-emulated log
1370 formats). To enable this logging set log_mime_hdrs to 'on'.
1376 LOC: Config.Log.useragent
1378 IFDEF: USE_USERAGENT_LOG
1380 Squid will write the User-Agent field from HTTP requests
1381 to the filename specified here. By default useragent_log
1388 LOC: Config.Log.referer
1390 IFDEF: USE_REFERER_LOG
1392 Squid will write the Referer field from HTTP requests to the
1393 filename specified here. By default referer_log is disabled.
1399 DEFAULT: @DEFAULT_PID_FILE@
1400 LOC: Config.pidFilename
1402 A filename to write the process-id to. To disable, enter "none".
1409 LOC: Config.debugOptions
1411 Logging options are set as section,level where each source file
1412 is assigned a unique section. Lower levels result in less
1413 output, Full debugging (level 9) can result in a very large
1414 log file, so be careful. The magic word "ALL" sets debugging
1415 levels for all sections. We recommend normally running with
1424 LOC: Config.onoff.log_fqdn
1426 Turn this on if you wish to log fully qualified domain names
1427 in the access.log. To do this Squid does a DNS lookup of all
1428 IP's connecting to it. This can (in some situations) increase
1429 latency, which makes your cache seem slower for interactive
1434 NAME: client_netmask
1436 LOC: Config.Addrs.client_netmask
1437 DEFAULT: 255.255.255.255
1439 A netmask for client addresses in logfiles and cachemgr output.
1440 Change this to protect the privacy of your cache clients.
1441 A netmask of 255.255.255.0 will log all IP's in that range with
1442 the last digit set to '0'.
1447 OPTIONS FOR EXTERNAL SUPPORT PROGRAMS
1448 -----------------------------------------------------------------------------
1454 LOC: Config.Ftp.anon_user
1456 If you want the anonymous login password to be more informative
1457 (and enable the use of picky ftp servers), set this to something
1458 reasonable for your domain, like wwwuser@somewhere.net
1460 The reason why this is domainless by default is the
1461 request can be made on the behalf of a user in any domain,
1462 depending on how the cache is used.
1463 Some ftp server also validate the email address is valid
1464 (for example perl.com).
1467 NAME: ftp_list_width
1470 LOC: Config.Ftp.list_width
1472 Sets the width of ftp listings. This should be set to fit in
1473 the width of a standard browser. Setting this too small
1474 can cut off long filenames when browsing ftp sites.
1480 LOC: Config.Ftp.passive
1482 If your firewall does not allow Squid to use passive
1483 connections, turn off this option.
1486 NAME: ftp_sanitycheck
1489 LOC: Config.Ftp.sanitycheck
1491 For security and data integrity reasons Squid by default performs
1492 sanity checks of the addresses of FTP data connections ensure the
1493 data connection is to the requested server. If you need to allow
1494 FTP connections to servers using another IP address for the data
1495 connection turn this off.
1498 NAME: check_hostnames
1501 LOC: Config.onoff.check_hostnames
1503 For security and stability reasons Squid by default checks
1504 hostnames for Internet standard RFC compliance. If you do not want
1505 Squid to perform these checks turn this directive off.
1508 NAME: ftp_telnet_protocol
1511 LOC: Config.Ftp.telnet
1513 The FTP protocol is officially defined to use the telnet protocol
1514 as transport channel for the control connection. However, many
1515 implementations are broken and does not respect this aspect of
1518 If you have trouble accessing files with ASCII code 255 in the
1519 path or similar problems involving this ASCII code you can
1520 try setting this directive to off. If that helps, report to the
1521 operator of the FTP server in question that their FTP server
1522 is broken and does not follow the FTP standard.
1525 NAME: cache_dns_program
1527 IFDEF: USE_DNSSERVERS
1528 DEFAULT: @DEFAULT_DNSSERVER@
1529 LOC: Config.Program.dnsserver
1531 Specify the location of the executable for dnslookup process.
1536 IFDEF: USE_DNSSERVERS
1538 LOC: Config.dnsChildren
1540 The number of processes spawn to service DNS name lookups.
1541 For heavily loaded caches on large servers, you should
1542 probably increase this value to at least 10. The maximum
1543 is 32. The default is 5.
1545 You must have at least one dnsserver process.
1548 NAME: dns_retransmit_interval
1551 LOC: Config.Timeout.idns_retransmit
1552 IFDEF: !USE_DNSSERVERS
1554 Initial retransmit interval for DNS queries. The interval is
1555 doubled each time all configured DNS servers have been tried.
1562 LOC: Config.Timeout.idns_query
1563 IFDEF: !USE_DNSSERVERS
1565 DNS Query timeout. If no response is received to a DNS query
1566 within this time all DNS servers for the queried domain
1567 are assumed to be unavailable.
1574 LOC: Config.onoff.res_defnames
1576 Normally the RES_DEFNAMES resolver option is disabled
1577 (see res_init(3)). This prevents caches in a hierarchy
1578 from interpreting single-component hostnames locally. To allow
1579 Squid to handle single-component names, enable this option.
1582 NAME: dns_nameservers
1585 LOC: Config.dns_nameservers
1587 Use this if you want to specify a list of DNS name servers
1588 (IP addresses) to use instead of those given in your
1589 /etc/resolv.conf file.
1590 On Windows platforms, if no value is specified here or in
1591 the /etc/resolv.conf file, the list of DNS name servers are
1592 taken from the Windows registry, both static and dynamic DHCP
1593 configurations are supported.
1595 Example: dns_nameservers 10.0.0.1 192.172.0.4
1600 DEFAULT: @DEFAULT_HOSTS@
1601 LOC: Config.etcHostsPath
1603 Location of the host-local IP name-address associations
1604 database. Most Operating Systems have such a file on different
1606 - Un*X & Linux: /etc/hosts
1607 - Windows NT/2000: %SystemRoot%\system32\drivers\etc\hosts
1608 (%SystemRoot% value install default is c:\winnt)
1609 - Windows XP/2003: %SystemRoot%\system32\drivers\etc\hosts
1610 (%SystemRoot% value install default is c:\windows)
1611 - Windows 9x/Me: %windir%\hosts
1612 (%windir% value is usually c:\windows)
1613 - Cygwin: /etc/hosts
1615 The file contains newline-separated definitions, in the
1616 form ip_address_in_dotted_form name [name ...] names are
1617 whitespace-separated. Lines beginning with an hash (#)
1618 character are comments.
1620 The file is checked at startup and upon configuration.
1621 If set to 'none', it won't be checked.
1622 If append_domain is used, that domain will be added to
1623 domain-local (i.e. not containing any dot character) host
1629 DEFAULT: @DEFAULT_DISKD@
1630 LOC: Config.Program.diskd
1632 Specify the location of the diskd executable.
1633 Note this is only useful if you have compiled in
1634 diskd as one of the store io modules.
1637 NAME: unlinkd_program
1640 DEFAULT: @DEFAULT_UNLINKD@
1641 LOC: Config.Program.unlinkd
1643 Specify the location of the executable for file deletion process.
1646 NAME: pinger_program
1648 DEFAULT: @DEFAULT_PINGER@
1649 LOC: Config.Program.pinger
1652 Specify the location of the executable for the pinger process.
1656 NAME: redirect_program
1658 LOC: Config.Program.redirect
1661 Specify the location of the executable for the URL redirector.
1662 Since they can perform almost any function there isn't one included.
1663 See the FAQ (section 15) for information on how to write one.
1664 By default, a redirector is not used.
1668 NAME: redirect_children
1671 LOC: Config.redirectChildren
1673 The number of redirector processes to spawn. If you start
1674 too few Squid will have to wait for them to process a backlog of
1675 URLs, slowing it down. If you start too many they will use RAM
1676 and other system resources.
1679 NAME: redirect_concurrency
1682 LOC: Config.redirectConcurrency
1684 The number of requests each redirector helper can handle in
1685 parallell. Defaults to 0 which indicates the redirector
1686 is a old-style singlethreaded redirector.
1689 NAME: redirect_rewrites_host_header
1692 LOC: Config.onoff.redir_rewrites_host
1694 By default Squid rewrites any Host: header in redirected
1695 requests. If you are running an accelerator this may
1696 not be a wanted effect of a redirector.
1698 WARNING: Entries are cached on the result of the URL rewriting
1699 process, so be careful if you have domain-virtual hosts.
1702 NAME: redirector_access
1705 LOC: Config.accessList.redirector
1707 If defined, this access list specifies which requests are
1708 sent to the redirector processes. By default all requests
1714 LOC: Config.authConfiguration
1717 This is used to pass parameters to the various authentication
1719 format: auth_param scheme parameter [setting]
1721 auth_param basic program @DEFAULT_PREFIX@/bin/ncsa_auth @DEFAULT_PREFIX@/etc/passwd
1722 would tell the basic authentication scheme it's program parameter.
1724 The order authentication prompts are presented to the client_agent
1725 is dependent on the order the scheme first appears in config file.
1726 IE has a bug (it's not rfc 2617 compliant) in that it will use the basic
1727 scheme if basic is the first entry presented, even if more secure schemes
1728 are presented. For now use the order in the file below. If other browsers
1729 have difficulties (don't recognize the schemes offered even if you are using
1730 basic) either put basic first, or disable the other schemes (by commenting
1731 out their program entry).
1733 Once an authentication scheme is fully configured, it can only be shutdown
1734 by shutting squid down and restarting. Changes can be made on the fly and
1735 activated with a reconfigure. I.E. You can change to a different helper,
1736 but not unconfigure the helper completely.
1738 === Parameters for the basic scheme follow. ===
1741 Specify the command for the external authenticator. Such a
1742 program reads a line containing "username password" and replies
1743 "ERR" in an endless loop. "ERR" responses may optionally be followed
1744 by a error description available as %m in the returned error page.
1745 If you use an authenticator, make sure you have 1 acl of type proxy_auth.
1746 By default, the basic authentication scheme is not used unless a program
1749 If you want to use the traditional proxy authentication,
1750 jump over to the ../helpers/basic_auth/NCSA directory and
1755 Then, set this line to something like
1757 auth_param basic program @DEFAULT_PREFIX@/libexec/ncsa_auth @DEFAULT_PREFIX@/etc/passwd
1759 "children" numberofchildren
1760 The number of authenticator processes to spawn (no default).
1761 If you start too few Squid will have to wait for them to
1762 process a backlog of usercode/password verifications, slowing
1763 it down. When password verifications are done via a (slow)
1764 network you are likely to need lots of authenticator
1766 auth_param basic children 5
1768 "concurrency" concurrency
1769 The number of concurrent requests the helper can process.
1770 The default of 0 is used for helpers who only supports
1771 one request at a time.
1772 auth_param basic concurrency 0
1775 Specifies the realm name which is to be reported to the
1776 client for the basic proxy authentication scheme (part of
1777 the text the user will see when prompted their username and
1778 password). There is no default.
1779 auth_param basic realm Squid proxy-caching web server
1781 "credentialsttl" timetolive
1782 Specifies how long squid assumes an externally validated
1783 username:password pair is valid for - in other words how
1784 often the helper program is called for that user. Set this
1785 low to force revalidation with short lived passwords. Note
1786 setting this high does not impact your susceptibility
1787 to replay attacks unless you are using an one-time password
1788 system (such as SecureID). If you are using such a system,
1789 you will be vulnerable to replay attacks unless you also
1790 use the max_user_ip ACL in an http_access rule.
1792 "casesensitive" on|off
1793 Specifies if usernames are case sensitive. Most user databases are
1794 case insensitive allowing the same username to be spelled using both
1795 lower and upper case letters, but some are case sensitive. This
1796 makes a big difference for user_max_ip ACL processing and similar.
1797 auth_param basic casesensitive off
1799 === Parameters for the digest scheme follow ===
1802 Specify the command for the external authenticator. Such
1803 a program reads a line containing "username":"realm" and
1804 replies with the appropriate H(A1) value base64 encoded or
1805 ERR if the user (or his H(A1) hash) does not exists.
1806 See rfc 2616 for the definition of H(A1).
1807 "ERR" responses may optionally be followed by a error description
1808 available as %m in the returned error page.
1810 By default, the digest authentication is not used unless a
1811 program is specified.
1813 If you want to use a digest authenticator, jump over to the
1814 helpers/digest_auth/ directory and choose the authenticator
1815 to use. In it's directory type
1819 Then, set this line to something like
1821 auth_param digest program @DEFAULT_PREFIX@/bin/digest_auth_pw @DEFAULT_PREFIX@/etc/digpass
1824 "children" numberofchildren
1825 The number of authenticator processes to spawn (no default).
1826 If you start too few Squid will have to wait for them to
1827 process a backlog of H(A1) calculations, slowing it down.
1828 When the H(A1) calculations are done via a (slow) network
1829 you are likely to need lots of authenticator processes.
1830 auth_param digest children 5
1833 Specifies the realm name which is to be reported to the
1834 client for the digest proxy authentication scheme (part of
1835 the text the user will see when prompted their username and
1836 password). There is no default.
1837 auth_param digest realm Squid proxy-caching web server
1839 "nonce_garbage_interval" timeinterval
1840 Specifies the interval that nonces that have been issued
1841 to client_agent's are checked for validity.
1843 "nonce_max_duration" timeinterval
1844 Specifies the maximum length of time a given nonce will be
1847 "nonce_max_count" number
1848 Specifies the maximum number of times a given nonce can be
1851 "nonce_strictness" on|off
1852 Determines if squid requires strict increment-by-1 behavior
1853 for nonce counts, or just incrementing (off - for use when
1854 useragents generate nonce counts that occasionally miss 1
1855 (ie, 1,2,4,6)). Default off.
1857 "check_nonce_count" on|off
1858 This directive if set to off can disable the nonce count check
1859 completely to work around buggy digest qop implementations in
1860 certain mainstream browser versions. Default on to check the
1861 nonce count to protect from authentication replay attacks.
1863 "post_workaround" on|off
1864 This is a workaround to certain buggy browsers who sends
1865 an incorrect request digest in POST requests when reusing
1866 the same nonce as acquired earlier on a GET request.
1868 === NTLM scheme options follow ===
1871 Specify the command for the external NTLM authenticator.
1872 Such a program reads exchanged NTLMSSP packets with
1873 the browser via Squid until authentication is completed.
1874 If you use an NTLM authenticator, make sure you have 1 acl
1875 of type proxy_auth. By default, the NTLM authenticator_program
1878 auth_param ntlm program @DEFAULT_PREFIX@/bin/ntlm_auth
1880 "children" numberofchildren
1881 The number of authenticator processes to spawn (no default).
1882 If you start too few Squid will have to wait for them to
1883 process a backlog of credential verifications, slowing it
1884 down. When credential verifications are done via a (slow)
1885 network you are likely to need lots of authenticator
1888 auth_param ntlm children 5
1891 If you experience problems with PUT/POST requests when using the
1892 Negotiate authentication scheme then you can try setting this to
1893 off. This will cause Squid to forcibly close the connection on
1894 the initial requests where the browser asks which schemes are
1895 supported by the proxy.
1897 auth_param ntlm keep_alive on
1899 === Options for configuring the NEGOTIATE auth-scheme follow ===
1902 Specify the command for the external Negotiate authenticator.
1903 This protocol is used in Microsoft Active-Directory enabled setups with
1904 the Microsoft Internet Explorer or Mozilla Firefox browsers.
1905 Its main purpose is to exchange credentials with the Squid proxy
1906 using the Kerberos mechanisms.
1907 If you use a Negotiate authenticator, make sure you have at least one acl
1908 of type proxy_auth active. By default, the negotiate authenticator_program
1910 The only supported program for this role is the ntlm_auth
1911 program distributed as part of Samba, version 4 or later.
1913 auth_param negotiate program @DEFAULT_PREFIX@/bin/ntlm_auth --helper-protocol=gss-spnego
1915 "children" numberofchildren
1916 The number of authenticator processes to spawn (no default).
1917 If you start too few Squid will have to wait for them to
1918 process a backlog of credential verifications, slowing it
1919 down. When crendential verifications are done via a (slow)
1920 network you are likely to need lots of authenticator
1922 auth_param negotiate children 5
1925 If you experience problems with PUT/POST requests when using the
1926 Negotiate authentication scheme then you can try setting this to
1927 off. This will cause Squid to forcibly close the connection on
1928 the initial requests where the browser asks which schemes are
1929 supported by the proxy.
1931 auth_param negotiate keep_alive on
1934 #Recommended minimum configuration per scheme:
1935 #auth_param negotiate program <uncomment and complete this line to activate>
1936 #auth_param negotiate children 5
1937 #auth_param negotiate keep_alive on
1938 #auth_param ntlm program <uncomment and complete this line to activate>
1939 #auth_param ntlm children 5
1940 #auth_param ntlm keep_alive on
1941 #auth_param digest program <uncomment and complete this line>
1942 #auth_param digest children 5
1943 #auth_param digest realm Squid proxy-caching web server
1944 #auth_param digest nonce_garbage_interval 5 minutes
1945 #auth_param digest nonce_max_duration 30 minutes
1946 #auth_param digest nonce_max_count 50
1947 #auth_param basic program <uncomment and complete this line>
1948 #auth_param basic children 5
1949 #auth_param basic realm Squid proxy-caching web server
1950 #auth_param basic credentialsttl 2 hours
1954 NAME: authenticate_cache_garbage_interval
1957 LOC: Config.authenticateGCInterval
1959 The time period between garbage collection across the
1960 username cache. This is a tradeoff between memory utilization
1961 (long intervals - say 2 days) and CPU (short intervals -
1962 say 1 minute). Only change if you have good reason to.
1965 NAME: authenticate_ttl
1968 LOC: Config.authenticateTTL
1970 The time a user & their credentials stay in the logged in
1971 user cache since their last request. When the garbage
1972 interval passes, all user credentials that have passed their
1973 TTL are removed from memory.
1976 NAME: authenticate_ip_ttl
1978 LOC: Config.authenticateIpTTL
1981 If you use proxy authentication and the 'max_user_ip' ACL,
1982 this directive controls how long Squid remembers the IP
1983 addresses associated with each user. Use a small value
1984 (e.g., 60 seconds) if your users might change addresses
1985 quickly, as is the case with dialups. You might be safe
1986 using a larger value (e.g., 2 hours) in a corporate LAN
1987 environment with relatively static address assignments.
1990 NAME: external_acl_type
1991 TYPE: externalAclHelper
1992 LOC: Config.externalAclHelperList
1995 This option defines external acl classes using a helper program
1996 to look up the status
1998 external_acl_type name [options] FORMAT.. /path/to/helper [helper arguments..]
2002 ttl=n TTL in seconds for cached results (defaults to 3600
2005 TTL for cached negative lookups (default same
2007 children=n Number of acl helper processes spawn to service
2008 external acl lookups of this type.
2009 concurrency=n concurrency level per process. Use 0 for old style
2010 helpers who can only process a single request at a
2012 cache=n result cache size, 0 is unbounded (default)
2013 grace=n Percentage remaining of TTL where a refresh of a
2014 cached entry should be initiated without needing to
2015 wait for a new reply. (default 0 for no grace period)
2016 protocol=2.5 Compatibility mode for Squid-2.5 external acl helpers
2018 FORMAT specifications
2020 %LOGIN Authenticated user login name
2021 %EXT_USER Username from external acl
2022 %IDENT Ident user name
2024 %SRCPORT Client source port
2026 %PROTO Requested protocol
2027 %PORT Requested port
2028 %PATH Requested URL path
2029 %METHOD Request method
2030 %MYADDR Squid interface address
2031 %MYPORT Squid http_port number
2032 %USER_CERT SSL User certificate in PEM format
2033 %USER_CERTCHAIN SSL User certificate chain in PEM format
2034 %USER_CERT_xx SSL User certificate subject attribute xx
2035 %USER_CA_xx SSL User certificate issuer attribute xx
2036 %{Header} HTTP request header
2037 %{Hdr:member} HTTP request header list member
2039 HTTP request header list member using ; as
2040 list separator. ; can be any non-alphanumeric
2043 In addition, any string specified in the referencing acl will
2044 also be included in the helper request line, after the specified
2045 formats (see the "acl external" directive)
2047 The helper receives lines per the above format specification,
2048 and returns lines starting with OK or ERR indicating the validity
2049 of the request and optionally followed by additional keywords with
2050 more details. To protect from odd characters the data is URL
2053 General result syntax:
2055 OK/ERR keyword=value ...
2059 user= The users name (login)
2060 password= The users password (for login= cache_peer option)
2061 message= Message describing the reason. Available as %o
2063 tag= Apply a tag to a request (for both ERR and OK results)
2064 Only sets a tag, does not alter existing tags.
2065 log= String to be logged in access.log. Available as
2066 %ea in logformat specifications
2068 Keyword values need to be URL escaped if they may contain
2069 contain whitespace or quotes.
2071 In Squid-2.5 compatibility mode quoting using " and \ is used
2072 instead of URL escaping.
2076 OPTIONS FOR TUNING THE CACHE
2077 -----------------------------------------------------------------------------
2080 NAME: wais_relay_host
2083 LOC: Config.Wais.relayHost
2086 NAME: wais_relay_port
2089 LOC: Config.Wais.relayPort
2091 Relay WAIS request to host (1st arg) at port (2 arg).
2095 NAME: request_header_max_size
2099 LOC: Config.maxRequestHeaderSize
2101 This specifies the maximum size for HTTP headers in a request.
2102 Request headers are usually relatively small (about 512 bytes).
2103 Placing a limit on the request header size will catch certain
2104 bugs (for example with persistent connections) and possibly
2105 buffer-overflow or denial-of-service attacks.
2108 NAME: request_body_max_size
2112 LOC: Config.maxRequestBodySize
2114 This specifies the maximum size for an HTTP request body.
2115 In other words, the maximum size of a PUT/POST request.
2116 A user who attempts to send a request with a body larger
2117 than this limit receives an "Invalid Request" error message.
2118 If you set this parameter to a zero (the default), there will
2119 be no limit imposed.
2122 NAME: refresh_pattern
2123 TYPE: refreshpattern
2127 usage: refresh_pattern [-i] regex min percent max [options]
2129 By default, regular expressions are CASE-SENSITIVE. To make
2130 them case-insensitive, use the -i option.
2132 'Min' is the time (in minutes) an object without an explicit
2133 expiry time should be considered fresh. The recommended
2134 value is 0, any higher values may cause dynamic applications
2135 to be erroneously cached unless the application designer
2136 has taken the appropriate actions.
2138 'Percent' is a percentage of the objects age (time since last
2139 modification age) an object without explicit expiry time
2140 will be considered fresh.
2142 'Max' is an upper limit on how long objects without an explicit
2143 expiry time will be considered fresh.
2145 options: override-expire
2155 override-expire enforces min age even if the server
2156 sent a Expires: header. Doing this VIOLATES the HTTP
2157 standard. Enabling this feature could make you liable
2158 for problems which it causes.
2160 override-lastmod enforces min age even on objects
2161 that were modified recently.
2163 reload-into-ims changes client no-cache or ``reload''
2164 to If-Modified-Since requests. Doing this VIOLATES the
2165 HTTP standard. Enabling this feature could make you
2166 liable for problems which it causes.
2168 ignore-reload ignores a client no-cache or ``reload''
2169 header. Doing this VIOLATES the HTTP standard. Enabling
2170 this feature could make you liable for problems which
2173 ignore-no-cache ignores any ``Pragma: no-cache'' and
2174 ``Cache-control: no-cache'' headers received from a server.
2175 The HTTP RFC never allows the use of this (Pragma) header
2176 from a server, only a client, though plenty of servers
2179 ignore-no-store ignores any ``Cache-control: no-store''
2180 headers received from a server. Doing this VIOLATES
2181 the HTTP standard. Enabling this feature could make you
2182 liable for problems which it causes.
2184 ignore-private ignores any ``Cache-control: private''
2185 headers received from a server. Doing this VIOLATES
2186 the HTTP standard. Enabling this feature could make you
2187 liable for problems which it causes.
2189 ignore-auth caches responses to requests with authorization,
2190 irrespective of ``Cache-control'' headers received from
2191 a server. Doing this VIOLATES the HTTP standard. Enabling
2192 this feature could make you liable for problems which
2195 refresh-ims causes squid to contact the origin server
2196 when a client issues an If-Modified-Since request. This
2197 ensures that the client will receive an updated version
2198 if one is available.
2200 Basically a cached object is:
2202 FRESH if expires < now, else STALE
2204 FRESH if lm-factor < percent, else STALE
2208 The refresh_pattern lines are checked in the order listed here.
2209 The first entry which matches is used. If none of the entries
2210 match the default will be used.
2212 Note, you must uncomment all the default lines if you want
2213 to change one. The default setting is only active if none is
2218 refresh_pattern ^ftp: 1440 20% 10080
2219 refresh_pattern ^gopher: 1440 0% 1440
2220 refresh_pattern . 0 20% 4320
2224 NAME: quick_abort_min
2228 LOC: Config.quickAbort.min
2231 NAME: quick_abort_max
2235 LOC: Config.quickAbort.max
2238 NAME: quick_abort_pct
2242 LOC: Config.quickAbort.pct
2244 The cache by default continues downloading aborted requests
2245 which are almost completed (less than 16 KB remaining). This
2246 may be undesirable on slow (e.g. SLIP) links and/or very busy
2247 caches. Impatient users may tie up file descriptors and
2248 bandwidth by repeatedly requesting and immediately aborting
2251 When the user aborts a request, Squid will check the
2252 quick_abort values to the amount of data transfered until
2255 If the transfer has less than 'quick_abort_min' KB remaining,
2256 it will finish the retrieval.
2258 If the transfer has more than 'quick_abort_max' KB remaining,
2259 it will abort the retrieval.
2261 If more than 'quick_abort_pct' of the transfer has completed,
2262 it will finish the retrieval.
2264 If you do not want any retrieval to continue after the client
2265 has aborted, set both 'quick_abort_min' and 'quick_abort_max'
2268 If you want retrievals to always continue if they are being
2269 cached set 'quick_abort_min' to '-1 KB'.
2272 NAME: read_ahead_gap
2273 COMMENT: buffer-size
2275 LOC: Config.readAheadGap
2278 The amount of data the cache will buffer ahead of what has been
2279 sent to the client when retrieving an object from another server.
2285 LOC: Config.negativeTtl
2288 Time-to-Live (TTL) for failed requests. Certain types of
2289 failures (such as "connection refused" and "404 Not Found") are
2290 negatively-cached for a configurable amount of time. The
2291 default is 5 minutes. Note that this is different from
2292 negative caching of DNS lookups.
2296 NAME: positive_dns_ttl
2299 LOC: Config.positiveDnsTtl
2302 Time-to-Live (TTL) for positive caching of successful DNS lookups.
2303 Default is 6 hours (360 minutes). If you want to minimize the
2304 use of Squid's ipcache, set this to 1, not 0.
2308 NAME: negative_dns_ttl
2311 LOC: Config.negativeDnsTtl
2314 Time-to-Live (TTL) for negative caching of failed DNS lookups.
2317 NAME: range_offset_limit
2320 LOC: Config.rangeOffsetLimit
2323 Sets a upper limit on how far into the the file a Range request
2324 may be to cause Squid to prefetch the whole file. If beyond this
2325 limit Squid forwards the Range request as it is and the result
2328 This is to stop a far ahead range request (lets say start at 17MB)
2329 from making Squid fetch the whole object up to that point before
2330 sending anything to the client.
2332 A value of -1 causes Squid to always fetch the object from the
2333 beginning so it may cache the result. (2.0 style)
2335 A value of 0 causes Squid to never fetch more than the
2336 client requested. (default)
2342 -----------------------------------------------------------------------------
2345 NAME: forward_timeout
2348 LOC: Config.Timeout.forward
2351 This parameter specifies how long Squid should at most attempt in
2352 finding a forwarding path for the request before giving up.
2355 NAME: connect_timeout
2358 LOC: Config.Timeout.connect
2361 This parameter specifies how long to wait for the TCP connect to
2362 the requested server or peer to complete before Squid should
2363 attempt to find another path where to forward the request.
2366 NAME: peer_connect_timeout
2369 LOC: Config.Timeout.peer_connect
2372 This parameter specifies how long to wait for a pending TCP
2373 connection to a peer cache. The default is 30 seconds. You
2374 may also set different timeout values for individual neighbors
2375 with the 'connect-timeout' option on a 'cache_peer' line.
2381 LOC: Config.Timeout.read
2384 The read_timeout is applied on server-side connections. After
2385 each successful read(), the timeout will be extended by this
2386 amount. If no data is read again after this amount of time,
2387 the request is aborted and logged with ERR_READ_TIMEOUT. The
2388 default is 15 minutes.
2392 NAME: request_timeout
2394 LOC: Config.Timeout.request
2397 How long to wait for an HTTP request after initial
2398 connection establishment.
2402 NAME: persistent_request_timeout
2404 LOC: Config.Timeout.persistent_request
2407 How long to wait for the next HTTP request on a persistent
2408 connection after the previous request completes.
2412 NAME: client_lifetime
2415 LOC: Config.Timeout.lifetime
2418 The maximum amount of time a client (browser) is allowed to
2419 remain connected to the cache process. This protects the Cache
2420 from having a lot of sockets (and hence file descriptors) tied up
2421 in a CLOSE_WAIT state from remote clients that go away without
2422 properly shutting down (either because of a network failure or
2423 because of a poor client implementation). The default is one
2426 NOTE: The default value is intended to be much larger than any
2427 client would ever need to be connected to your cache. You
2428 should probably change client_lifetime only as a last resort.
2429 If you seem to have many client connections tying up
2430 filedescriptors, we recommend first tuning the read_timeout,
2431 request_timeout, persistent_request_timeout and quick_abort values.
2434 NAME: half_closed_clients
2436 LOC: Config.onoff.half_closed_clients
2439 Some clients may shutdown the sending side of their TCP
2440 connections, while leaving their receiving sides open. Sometimes,
2441 Squid can not tell the difference between a half-closed and a
2442 fully-closed TCP connection. By default, half-closed client
2443 connections are kept open until a read(2) or write(2) on the
2444 socket returns an error. Change this option to 'off' and Squid
2445 will immediately close client connections when read(2) returns
2446 "no more data to read."
2451 LOC: Config.Timeout.pconn
2452 DEFAULT: 120 seconds
2454 Timeout for idle persistent connections to servers and other
2461 LOC: Config.Timeout.ident
2464 Maximum time to wait for IDENT lookups to complete.
2466 If this is too high, and you enabled IDENT lookups from untrusted
2467 users, you might be susceptible to denial-of-service by having
2468 many ident requests going at once.
2472 NAME: shutdown_lifetime
2475 LOC: Config.shutdownLifetime
2478 When SIGTERM or SIGHUP is received, the cache is put into
2479 "shutdown pending" mode until all active sockets are closed.
2480 This value is the lifetime to set for all open descriptors
2481 during shutdown mode. Any active clients after this many
2482 seconds will receive a 'timeout' message.
2487 -----------------------------------------------------------------------------
2495 Defining an Access List
2497 acl aclname acltype string1 ...
2498 acl aclname acltype "file" ...
2500 when using "file", the file should contain one item per line
2502 acltype is one of the types described below
2504 By default, regular expressions are CASE-SENSITIVE. To make
2505 them case-insensitive, use the -i option.
2507 acl aclname src ip-address/netmask ... (clients IP address)
2508 acl aclname src addr1-addr2/netmask ... (range of addresses)
2509 acl aclname dst ip-address/netmask ... (URL host's IP address)
2510 acl aclname myip ip-address/netmask ... (local socket IP address)
2512 acl aclname arp mac-address ... (xx:xx:xx:xx:xx:xx notation)
2513 # The arp ACL requires the special configure option --enable-arp-acl.
2514 # Furthermore, the ARP ACL code is not portable to all operating systems.
2515 # It works on Linux, Solaris, Windows, FreeBSD, and some other *BSD variants.
2517 # NOTE: Squid can only determine the MAC address for clients that are on
2518 # the same subnet. If the client is on a different subnet, then Squid cannot
2519 # find out its MAC address.
2521 acl aclname srcdomain .foo.com ... # reverse lookup, client IP
2522 acl aclname dstdomain .foo.com ... # Destination server from URL
2523 acl aclname srcdom_regex [-i] xxx ... # regex matching client name
2524 acl aclname dstdom_regex [-i] xxx ... # regex matching server
2525 # For dstdomain and dstdom_regex a reverse lookup is tried if a IP
2526 # based URL is used and no match is found. The name "none" is used
2527 # if the reverse lookup fails.
2529 acl aclname http_status 200 301 500- 400-403 ... # status code in reply
2531 acl aclname time [day-abbrevs] [h1:m1-h2:m2]
2540 h1:m1 must be less than h2:m2
2541 acl aclname url_regex [-i] ^http:// ... # regex matching on whole URL
2542 acl aclname urlpath_regex [-i] \.gif$ ... # regex matching on URL path
2543 acl aclname port 80 70 21 ...
2544 acl aclname port 0-1024 ... # ranges allowed
2545 acl aclname myport 3128 ... # (local socket TCP port)
2546 acl aclname proto HTTP FTP ...
2547 acl aclname method GET POST ...
2548 acl aclname browser [-i] regexp ...
2549 # pattern match on User-Agent header
2550 acl aclname referer_regex [-i] regexp ...
2551 # pattern match on Referer header
2552 # Referer is highly unreliable, so use with care
2553 acl aclname ident username ...
2554 acl aclname ident_regex [-i] pattern ...
2555 # string match on ident output.
2556 # use REQUIRED to accept any non-null ident.
2557 acl aclname src_as number ...
2558 acl aclname dst_as number ...
2559 # Except for access control, AS numbers can be used for
2560 # routing of requests to specific caches. Here's an
2561 # example for routing all requests for AS#1241 and only
2562 # those to mycache.mydomain.net:
2563 # acl asexample dst_as 1241
2564 # cache_peer_access mycache.mydomain.net allow asexample
2565 # cache_peer_access mycache_mydomain.net deny all
2567 acl aclname proxy_auth [-i] username ...
2568 acl aclname proxy_auth_regex [-i] pattern ...
2569 # list of valid usernames
2570 # use REQUIRED to accept any valid username.
2572 # NOTE: when a Proxy-Authentication header is sent but it is not
2573 # needed during ACL checking the username is NOT logged
2576 # NOTE: proxy_auth requires a EXTERNAL authentication program
2577 # to check username/password combinations (see
2578 # auth_param directive).
2580 # NOTE: proxy_auth can't be used in a transparent proxy as
2581 # the browser needs to be configured for using a proxy in order
2582 # to respond to proxy authentication.
2584 acl aclname snmp_community string ...
2585 # A community string to limit access to your SNMP Agent
2588 # acl snmppublic snmp_community public
2590 acl aclname maxconn number
2591 # This will be matched when the client's IP address has
2592 # more than <number> HTTP connections established.
2594 acl aclname max_user_ip [-s] number
2595 # This will be matched when the user attempts to log in from more
2596 # than <number> different ip addresses. The authenticate_ip_ttl
2597 # parameter controls the timeout on the ip entries.
2598 # If -s is specified the limit is strict, denying browsing
2599 # from any further IP addresses until the ttl has expired. Without
2600 # -s Squid will just annoy the user by "randomly" denying requests.
2601 # (the counter is reset each time the limit is reached and a
2602 # request is denied)
2603 # NOTE: in acceleration mode or where there is mesh of child proxies,
2604 # clients may appear to come from multiple addresses if they are
2605 # going through proxy farms, so a limit of 1 may cause user problems.
2607 acl aclname req_mime_type mime-type1 ...
2608 # regex match agains the mime type of the request generated
2609 # by the client. Can be used to detect file upload or some
2610 # types HTTP tunneling requests.
2611 # NOTE: This does NOT match the reply. You cannot use this
2612 # to match the returned file type.
2614 acl aclname rep_mime_type mime-type1 ...
2615 # regex match against the mime type of the reply received by
2616 # squid. Can be used to detect file download or some
2617 # types HTTP tunneling requests.
2618 # NOTE: This has no effect in http_access rules. It only has
2619 # effect in rules that affect the reply data stream such as
2620 # http_reply_access.
2622 acl acl_name external class_name [arguments...]
2623 # external ACL lookup via a helper class defined by the
2624 # external_acl_type directive.
2626 acl aclname user_cert attribute values...
2627 # match against attributes in a user SSL certificate
2628 # attribute is one of DN/C/O/CN/L/ST
2630 acl aclname ca_cert attribute values...
2631 # match against attributes a users issuing CA SSL certificate
2632 # attribute is one of DN/C/O/CN/L/ST
2634 acl aclname ext_user username ...
2635 acl aclname ext_user_regex [-i] pattern ...
2636 # string match on username returned by external acl processing
2637 # use REQUIRED to accept any non-null user name.
2640 acl macaddress arp 09:00:2b:23:45:67
2641 acl myexample dst_as 1241
2642 acl password proxy_auth REQUIRED
2643 acl fileupload req_mime_type -i ^multipart/form-data$
2644 acl javascript rep_mime_type -i ^application/x-javascript$
2647 #Recommended minimum configuration:
2648 acl all src 0.0.0.0/0.0.0.0
2649 acl manager proto cache_object
2650 acl localhost src 127.0.0.1/255.255.255.255
2651 acl to_localhost dst 127.0.0.0/8
2652 acl SSL_ports port 443 563
2653 acl Safe_ports port 80 # http
2654 acl Safe_ports port 21 # ftp
2655 acl Safe_ports port 443 563 # https, snews
2656 acl Safe_ports port 70 # gopher
2657 acl Safe_ports port 210 # wais
2658 acl Safe_ports port 1025-65535 # unregistered ports
2659 acl Safe_ports port 280 # http-mgmt
2660 acl Safe_ports port 488 # gss-http
2661 acl Safe_ports port 591 # filemaker
2662 acl Safe_ports port 777 # multiling http
2663 acl CONNECT method CONNECT
2669 LOC: Config.accessList.http
2671 DEFAULT_IF_NONE: deny all
2673 Allowing or Denying access based on defined access lists
2675 Access to the HTTP port:
2676 http_access allow|deny [!]aclname ...
2678 NOTE on default values:
2680 If there are no "access" lines present, the default is to deny
2683 If none of the "access" lines cause a match, the default is the
2684 opposite of the last line in the list. If the last line was
2685 deny, the default is allow. Conversely, if the last line
2686 is allow, the default will be deny. For these reasons, it is a
2687 good idea to have an "deny all" or "allow all" entry at the end
2688 of your access lists to avoid potential confusion.
2691 #Recommended minimum configuration:
2693 # Only allow cachemgr access from localhost
2694 http_access allow manager localhost
2695 http_access deny manager
2696 # Deny requests to unknown ports
2697 http_access deny !Safe_ports
2698 # Deny CONNECT to other than SSL ports
2699 http_access deny CONNECT !SSL_ports
2701 # We strongly recommend the following be uncommented to protect innocent
2702 # web applications running on the proxy server who think the only
2703 # one who can access services on "localhost" is a local user
2704 #http_access deny to_localhost
2706 # INSERT YOUR OWN RULE(S) HERE TO ALLOW ACCESS FROM YOUR CLIENTS
2708 # Example rule allowing access from your local networks. Adapt
2709 # to list your (internal) IP networks from where browsing should
2711 #acl our_networks src 192.168.1.0/24 192.168.2.0/24
2712 #http_access allow our_networks
2714 # And finally deny all other access to this proxy
2715 http_access deny all
2719 NAME: http_reply_access
2721 LOC: Config.accessList.reply
2723 DEFAULT_IF_NONE: allow all
2725 Allow replies to client requests. This is complementary to http_access.
2727 http_reply_access allow|deny [!] aclname ...
2729 NOTE: if there are no access lines present, the default is to allow
2732 If none of the access lines cause a match the opposite of the
2733 last line will apply. Thus it is good practice to end the rules
2734 with an "allow all" or "deny all" entry.
2737 #Recommended minimum configuration:
2739 # Insert your own rules here.
2742 # and finally allow by default
2743 http_reply_access allow all
2750 LOC: Config.accessList.icp
2752 DEFAULT_IF_NONE: deny all
2754 Allowing or Denying access to the ICP port based on defined
2757 icp_access allow|deny [!]aclname ...
2759 See http_access for details
2762 #Allow ICP queries from everyone
2763 icp_access allow all
2770 LOC: Config.accessList.miss
2773 Use to force your neighbors to use you as a sibling instead of
2774 a parent. For example:
2776 acl localclients src 172.16.0.0/16
2777 miss_access allow localclients
2778 miss_access deny !localclients
2780 This means only your local clients are allowed to fetch
2781 MISSES and all other clients can only fetch HITS.
2783 By default, allow all clients who passed the http_access rules
2784 to fetch MISSES from us.
2788 # miss_access allow all
2793 NAME: cache_peer_access
2798 Similar to 'cache_peer_domain' but provides more flexibility by
2801 cache_peer_access cache-host allow|deny [!]aclname ...
2803 The syntax is identical to 'http_access' and the other lists of
2804 ACL elements. See the comments for 'http_access' below, or
2805 the Squid FAQ (http://www.squid-cache.org/FAQ/FAQ-10.html).
2808 NAME: ident_lookup_access
2812 DEFAULT_IF_NONE: deny all
2813 LOC: Config.accessList.identLookup
2815 A list of ACL elements which, if matched, cause an ident
2816 (RFC 931) lookup to be performed for this request. For
2817 example, you might choose to always perform ident lookups
2818 for your main multi-user Unix boxes, but not for your Macs
2819 and PCs. By default, ident lookups are not performed for
2822 To enable ident lookups for specific client addresses, you
2823 can follow this example:
2825 acl ident_aware_hosts src 198.168.1.0/255.255.255.0
2826 ident_lookup_access allow ident_aware_hosts
2827 ident_lookup_access deny all
2829 Only src type ACL checks are fully supported. A src_domain
2830 ACL might work at times, but it will not always provide
2834 NAME: tcp_outgoing_tos tcp_outgoing_ds tcp_outgoing_dscp
2837 LOC: Config.accessList.outgoing_tos
2839 Allows you to select a TOS/Diffserv value to mark outgoing
2840 connections with, based on the username or source address
2843 tcp_outgoing_tos ds-field [!]aclname ...
2845 Example where normal_service_net uses the TOS value 0x00
2846 and normal_service_net uses 0x20
2848 acl normal_service_net src 10.0.0.0/255.255.255.0
2849 acl good_service_net src 10.0.1.0/255.255.255.0
2850 tcp_outgoing_tos 0x00 normal_service_net 0x00
2851 tcp_outgoing_tos 0x20 good_service_net
2853 TOS/DSCP values really only have local significance - so you should
2854 know what you're specifying. For more, see RFC 2474
2856 The TOS/DSCP byte must be exactly that - a byte, value 0 - 255, or
2857 "default" to use whatever default your host has.
2859 Processing proceeds in the order specified, and stops at first fully
2863 NAME: tcp_outgoing_address
2866 LOC: Config.accessList.outgoing_address
2868 Allows you to map requests to different outgoing IP addresses
2869 based on the username or sourceaddress of the user making
2872 tcp_outgoing_address ipaddr [[!]aclname] ...
2874 Example where requests from 10.0.0.0/24 will be forwarded
2875 with source address 10.1.0.1, 10.0.2.0/24 forwarded with
2876 source address 10.1.0.2 and the rest will be forwarded with
2877 source address 10.1.0.3.
2879 acl normal_service_net src 10.0.0.0/255.255.255.0
2880 acl good_service_net src 10.0.1.0/255.255.255.0
2881 tcp_outgoing_address 10.0.0.1 normal_service_net
2882 tcp_outgoing_address 10.0.0.2 good_service_net
2883 tcp_outgoing_address 10.0.0.3
2885 Processing proceeds in the order specified, and stops at first fully
2889 NAME: reply_header_max_size
2893 LOC: Config.maxReplyHeaderSize
2895 This specifies the maximum size for HTTP headers in a reply.
2896 Reply headers are usually relatively small (about 512 bytes).
2897 Placing a limit on the reply header size will catch certain
2898 bugs (for example with persistent connections) and possibly
2899 buffer-overflow or denial-of-service attacks.
2902 NAME: reply_body_max_size
2903 COMMENT: size [acl acl...]
2906 LOC: Config.ReplyBodySize
2908 This option specifies the maximum size of a reply body. It can be
2909 used to prevent users from downloading very large files, such as
2910 MP3's and movies. When the reply headers are received, the
2911 reply_body_max_size lines are processed, and the first line where
2912 all (if any) listed ACLs are true is used as the maximum body size
2915 This size is checked twice. First when we get the reply headers,
2916 we check the content-length value. If the content length value exists
2917 and is larger than the allowed size, the request is denied and the
2918 user receives an error message that says "the request or reply
2919 is too large." If there is no content-length, and the reply
2920 size exceeds this limit, the client's connection is just closed
2921 and they will receive a partial reply.
2923 WARNING: downstream caches probably can not detect a partial reply
2924 if there is no content-length header, so they will cache
2925 partial responses and give them out as hits. You should NOT
2926 use this option if you have downstream caches.
2928 WARNING: A maximum size smaller than the size of squid's error messages
2929 will cause an infinite loop and crash squid. Ensure that the smallest
2930 non-zero value you use is greater that the maximum header size plus
2931 the size of your largest error page.
2933 If you set this parameter none (the default), there will be
2939 LOC: Config.accessList.log
2941 COMMENT: allow|deny acl acl...
2943 This options allows you to control which requests gets logged
2944 to access.log (see access_log directive). Requests denied for
2945 logging will also not be accounted for in performance counters.
2949 ADMINISTRATIVE PARAMETERS
2950 -----------------------------------------------------------------------------
2956 LOC: Config.adminEmail
2958 Email-address of local cache manager who will receive
2959 mail if the cache dies. The default is "webmaster."
2966 LOC: Config.EmailFrom
2968 From: email-address for mail sent when the cache dies.
2969 The default is to use 'appname@unique_hostname'.
2970 Default appname value is "squid", can be changed into
2971 src/globals.h before building squid.
2978 LOC: Config.EmailProgram
2980 Email program used to send mail if the cache dies.
2981 The default is "mail". The specified program must complain
2982 with the standard Unix mail syntax:
2983 mail_program recipient < mailfile
2984 Optional command line options can be specified.
2988 NAME: cache_effective_user
2991 LOC: Config.effectiveUser
2993 If you start Squid as root, it will change its effective/real
2994 UID/GID to the user specified below. The default is to change
2995 to UID to nobody. If you define cache_effective_user, but not
2996 cache_effective_group, Squid sets the GID to the effective
2997 user's default group ID (taken from the password file) and
2998 supplementary group list from the from groups membership of
2999 cache_effective_user.
3003 NAME: cache_effective_group
3006 LOC: Config.effectiveGroup
3008 If you want Squid to run with a specific GID regardless of
3009 the group memberships of the effective user then set this
3010 to the group (or GID) you want Squid to run as. When set
3011 all other group privileges of the effective user is ignored
3012 and only this GID is effective. If Squid is not started as
3013 root the user starting Squid must be member of the specified
3018 NAME: httpd_suppress_version_string
3022 LOC: Config.onoff.httpd_suppress_version_string
3024 Suppress Squid version string info in HTTP headers and HTML error pages.
3028 NAME: visible_hostname
3030 LOC: Config.visibleHostname
3033 If you want to present a special hostname in error messages, etc,
3034 define this. Otherwise, the return value of gethostname()
3035 will be used. If you have multiple caches in a cluster and
3036 get errors about IP-forwarding you must set them to have individual
3037 names with this setting.
3041 NAME: unique_hostname
3043 LOC: Config.uniqueHostname
3046 If you want to have multiple machines with the same
3047 'visible_hostname' you must give each machine a different
3048 'unique_hostname' so forwarding loops can be detected.
3052 NAME: hostname_aliases
3054 LOC: Config.hostnameAliases
3057 A list of other DNS names your cache has.
3061 OPTIONS FOR THE CACHE REGISTRATION SERVICE
3062 -----------------------------------------------------------------------------
3064 This section contains parameters for the (optional) cache
3065 announcement service. This service is provided to help
3066 cache administrators locate one another in order to join or
3067 create cache hierarchies.
3069 An 'announcement' message is sent (via UDP) to the registration
3070 service by Squid. By default, the announcement message is NOT
3071 SENT unless you enable it with 'announce_period' below.
3073 The announcement message includes your hostname, plus the
3074 following information from this configuration file:
3080 All current information is processed regularly and made
3081 available on the Web at http://www.ircache.net/Cache/Tracker/.
3084 NAME: announce_period
3086 LOC: Config.Announce.period
3089 This is how frequently to send cache announcements. The
3090 default is `0' which disables sending the announcement
3093 To enable announcing your cache, just uncomment the line
3097 #To enable announcing your cache, just uncomment the line below.
3098 #announce_period 1 day
3105 DEFAULT: tracker.ircache.net
3106 LOC: Config.Announce.host
3112 LOC: Config.Announce.file
3118 LOC: Config.Announce.port
3120 announce_host and announce_port set the hostname and port
3121 number where the registration message will be sent.
3123 Hostname will default to 'tracker.ircache.net' and port will
3124 default default to 3131. If the 'filename' argument is given,
3125 the contents of that file will be included in the announce
3129 NAME: httpd_accel_surrogate_id
3132 LOC: Config.Accel.surrogate_id
3135 Surrogates (http://www.esi.org/architecture_spec_1.0.html)
3136 need an identification token to allow control targeting. Because
3137 a farm of surrogates may all perform the same tasks, they may share
3138 an identification token.
3141 NAME: http_accel_surrogate_remote
3146 LOC: Config.onoff.surrogate_is_remote
3148 Remote surrogates (such as those in a CDN) honour Surrogate-Control: no-store-remote.
3149 Set this to on to have squid behave as a remote surrogate.
3154 COMMENT: libxml2|expat|custom
3156 LOC: ESIParser::Type
3159 ESI markup is not strictly XML compatible. The custom ESI parser
3160 will give higher performance, but cannot handle non ASCII character
3166 -----------------------------------------------------------------------------
3171 LOC: Config.dns_testname_list
3173 DEFAULT_IF_NONE: netscape.com internic.net nlanr.net microsoft.com
3175 The DNS tests exit as soon as the first site is successfully looked up
3177 This test can be disabled with the -D command line option.
3181 NAME: logfile_rotate
3184 LOC: Config.Log.rotateNumber
3186 Specifies the number of logfile rotations to make when you
3187 type 'squid -k rotate'. The default is 10, which will rotate
3188 with extensions 0 through 9. Setting logfile_rotate to 0 will
3189 disable the rotation, but the logfiles are still closed and
3190 re-opened. This will enable you to rename the logfiles
3191 yourself just before sending the rotate signal.
3193 Note, the 'squid -k rotate' command normally sends a USR1
3194 signal to the running squid process. In certain situations
3195 (e.g. on Linux with Async I/O), USR1 is used for other
3196 purposes, so -k rotate uses another signal. It is best to get
3197 in the habit of using 'squid -k rotate' instead of 'kill -USR1
3204 LOC: Config.appendDomain
3207 Appends local domain name to hostnames without any dots in
3208 them. append_domain must begin with a period.
3210 Be warned there are now Internet names with no dots in
3211 them using only top-domain names, so setting this may
3212 cause some Internet sites to become unavailable.
3215 append_domain .yourdomain.com
3219 NAME: tcp_recv_bufsize
3223 LOC: Config.tcpRcvBufsz
3225 Size of receive buffer to set for TCP sockets. Probably just
3226 as easy to change your kernel's default. Set to zero to use
3227 the default buffer size.
3232 LOC: Config.errHtmlText
3235 HTML text to include in error messages. Make this a "mailto"
3236 URL to your admin address, or maybe just a link to your
3237 organizations Web page.
3239 To include this in your error messages, you must rewrite
3240 the error template files (found in the "errors" directory).
3241 Wherever you want the 'err_html_text' line to appear,
3242 insert a %L tag in the error template file.
3245 NAME: email_err_data
3248 LOC: Config.onoff.emailErrData
3251 If enabled, information about the occurred error will be
3252 included in the mailto links of the ERR pages (if %W is set)
3253 so that the email body contains the data.
3254 Syntax is <A HREF="mailto:%w%W">%w</A>
3260 LOC: Config.denyInfoList
3263 Usage: deny_info err_page_name acl
3264 or deny_info http://... acl
3265 Example: deny_info ERR_CUSTOM_ACCESS_DENIED bad_guys
3267 This can be used to return a ERR_ page for requests which
3268 do not pass the 'http_access' rules. A single ACL will cause
3269 the http_access check to fail. If a 'deny_info' line exists
3270 for that ACL Squid returns a corresponding error page.
3272 You may use ERR_ pages that come with Squid or create your own pages
3273 and put them into the configured errors/ directory.
3275 Alternatively you can specify an error URL. The browsers will
3276 get redirected (302) to the specified URL. %s in the redirection
3277 URL will be replaced by the requested URL.
3279 Alternatively you can tell Squid to reset the TCP connection
3280 by specifying TCP_RESET.
3287 LOC: Config.onoff.mem_pools
3289 If set, Squid will keep pools of allocated (but unused) memory
3290 available for future use. If memory is a premium on your
3291 system and you believe your malloc library outperforms Squid
3292 routines, disable this.
3295 NAME: memory_pools_limit
3299 LOC: Config.MemPools.limit
3301 Used only with memory_pools on:
3302 memory_pools_limit 50 MB
3304 If set to a non-zero value, Squid will keep at most the specified
3305 limit of allocated (but unused) memory in memory pools. All free()
3306 requests that exceed this limit will be handled by your malloc
3307 library. Squid does not pre-allocate any memory, just safe-keeps
3308 objects that otherwise would be free()d. Thus, it is safe to set
3309 memory_pools_limit to a reasonably high value even if your
3310 configuration will use less memory.
3312 If set to zero, Squid will keep all memory it can. That is, there
3313 will be no limit on the total amount of memory used for safe-keeping.
3315 To disable memory allocation optimization, do not set
3316 memory_pools_limit to 0. Set memory_pools to "off" instead.
3318 An overhead for maintaining memory pools is not taken into account
3319 when the limit is checked. This overhead is close to four bytes per
3320 object kept. However, pools may actually _save_ memory because of
3321 reduced memory thrashing in your malloc library.
3325 IFDEF: HTTP_VIOLATIONS
3329 LOC: Config.onoff.via
3331 If set (default), Squid will include a Via header in requests and
3332 replies as required by RFC2616.
3339 LOC: opt_forwarded_for
3341 If set, Squid will include your system's IP address or name
3342 in the HTTP requests it forwards. By default it looks like
3345 X-Forwarded-For: 192.1.2.3
3347 If you disable this, it will appear as
3349 X-Forwarded-For: unknown
3352 NAME: log_icp_queries
3356 LOC: Config.onoff.log_udp
3358 If set, ICP queries are logged to access.log. You may wish
3359 do disable this if your ICP load is VERY high to speed things
3360 up or to simplify log analysis.
3367 LOC: Config.onoff.icp_hit_stale
3369 If you want to return ICP_HIT for stale cache objects, set this
3370 option to 'on'. If you have sibling relationships with caches
3371 in other administrative domains, this should be 'off'. If you only
3372 have sibling relationships with caches under your control,
3373 it is probably okay to set this to 'on'.
3374 If set to 'on', your siblings should use the option "allow-miss"
3375 on their cache_peer lines for connecting to you.
3379 NAME: minimum_direct_hops
3382 LOC: Config.minDirectHops
3384 If using the ICMP pinging stuff, do direct fetches for sites
3385 which are no more than this many hops away.
3388 NAME: minimum_direct_rtt
3391 LOC: Config.minDirectRtt
3393 If using the ICMP pinging stuff, do direct fetches for sites
3394 which are no more than this many rtt milliseconds away.
3397 NAME: cachemgr_passwd
3398 TYPE: cachemgrpasswd
3400 LOC: Config.passwd_list
3402 Specify passwords for cachemgr operations.
3404 Usage: cachemgr_passwd password action action ...
3406 Some valid actions are (see cache manager menu for a full list):
3445 * Indicates actions which will not be performed without a
3446 valid password, others can be performed if not listed here.
3448 To disable an action, set the password to "disable".
3449 To allow performing an action without a password, set the
3452 Use the keyword "all" to set the same password for all actions.
3455 cachemgr_passwd secret shutdown
3456 cachemgr_passwd lesssssssecret info stats/objects
3457 cachemgr_passwd disable all
3460 NAME: store_avg_object_size
3464 LOC: Config.Store.avgObjectSize
3466 Average object size, used to estimate number of objects your
3467 cache can hold. See doc/Release-Notes-1.1.txt. The default is
3471 NAME: store_objects_per_bucket
3474 LOC: Config.Store.objectsPerBucket
3476 Target number of objects per bucket in the store hash table.
3477 Lowering this value increases the total number of buckets and
3478 also the storage maintenance rate. The default is 20.
3485 LOC: Config.onoff.client_db
3487 If you want to disable collecting per-client statistics,
3488 turn off client_db here.
3495 LOC: Config.Netdb.low
3501 LOC: Config.Netdb.high
3503 The low and high water marks for the ICMP measurement
3504 database. These are counts, not percents. The defaults are
3505 900 and 1000. When the high water mark is reached, database
3506 entries will be deleted until the low mark is reached.
3510 NAME: netdb_ping_period
3512 LOC: Config.Netdb.period
3515 The minimum period for measuring a site. There will be at
3516 least this much delay between successive pings to the same
3517 network. The default is five minutes.
3525 LOC: Config.onoff.query_icmp
3527 If you want to ask your peers to include ICMP data in their ICP
3528 replies, enable this option.
3530 If your peer has configured Squid (during compilation) with
3531 '--enable-icmp' that peer will send ICMP pings to origin server
3532 sites of the URLs it receives. If you enable this option the
3533 ICP replies from that peer will include the ICMP data (if available).
3534 Then, when choosing a parent cache, Squid will choose the parent with
3535 the minimal RTT to the origin server. When this happens, the
3536 hierarchy field of the access.log will be
3537 "CLOSEST_PARENT_MISS". This option is off by default.
3540 NAME: test_reachability
3544 LOC: Config.onoff.test_reachability
3546 When this is 'on', ICP MISS replies will be ICP_MISS_NOFETCH
3547 instead of ICP_MISS if the target host is NOT in the ICMP
3548 database, or has a zero RTT.
3555 LOC: Config.onoff.buffered_logs
3557 cache.log log file is written with stdio functions, and as such
3558 it can be buffered or unbuffered. By default it will be unbuffered.
3559 Buffering it can speed up the writing slightly (though you are
3560 unlikely to need to worry unless you run with tons of debugging
3561 enabled in which case performance will suffer badly anyway..).
3564 NAME: refresh_all_ims
3568 LOC: Config.onoff.refresh_all_ims
3570 When you enable this option, squid will always check
3571 the origin server for an update when a client sends an
3572 If-Modified-Since request. Many browsers use IMS
3573 requests when the user requests a reload, and this
3574 ensures those clients receive the latest version.
3576 By default (off), squid may return a Not Modified response
3577 based on the age of the cached version.
3580 NAME: reload_into_ims
3581 IFDEF: HTTP_VIOLATIONS
3585 LOC: Config.onoff.reload_into_ims
3587 When you enable this option, client no-cache or ``reload''
3588 requests will be changed to If-Modified-Since requests.
3589 Doing this VIOLATES the HTTP standard. Enabling this
3590 feature could make you liable for problems which it
3593 see also refresh_pattern for a more selective approach.
3598 LOC: Config.accessList.AlwaysDirect
3601 Usage: always_direct allow|deny [!]aclname ...
3603 Here you can use ACL elements to specify requests which should
3604 ALWAYS be forwarded directly to origin servers. For example,
3605 to always directly forward requests for local servers use
3608 acl local-servers dstdomain my.domain.net
3609 always_direct allow local-servers
3611 To always forward FTP requests directly, use
3614 always_direct allow FTP
3616 NOTE: There is a similar, but opposite option named
3617 'never_direct'. You need to be aware that "always_direct deny
3618 foo" is NOT the same thing as "never_direct allow foo". You
3619 may need to use a deny rule to exclude a more-specific case of
3620 some other rule. Example:
3622 acl local-external dstdomain external.foo.net
3623 acl local-servers dstdomain .foo.net
3624 always_direct deny local-external
3625 always_direct allow local-servers
3627 This option replaces some v1.1 options such as local_domain
3633 LOC: Config.accessList.NeverDirect
3636 Usage: never_direct allow|deny [!]aclname ...
3638 never_direct is the opposite of always_direct. Please read
3639 the description for always_direct if you have not already.
3641 With 'never_direct' you can use ACL elements to specify
3642 requests which should NEVER be forwarded directly to origin
3643 servers. For example, to force the use of a proxy for all
3644 requests, except those in your local domain use something like:
3646 acl local-servers dstdomain .foo.net
3647 acl all src 0.0.0.0/0.0.0.0
3648 never_direct deny local-servers
3649 never_direct allow all
3651 or if Squid is inside a firewall and there are local intranet
3652 servers inside the firewall use something like:
3654 acl local-intranet dstdomain .foo.net
3655 acl local-external dstdomain external.foo.net
3656 always_direct deny local-external
3657 always_direct allow local-intranet
3658 never_direct allow all
3660 This option replaces some v1.1 options such as inside_firewall
3664 NAME: request_header_access
3665 IFDEF: HTTP_VIOLATIONS
3666 TYPE: http_header_access[]
3667 LOC: Config.request_header_access
3670 Usage: request_header_access header_name allow|deny [!]aclname ...
3672 WARNING: Doing this VIOLATES the HTTP standard. Enabling
3673 this feature could make you liable for problems which it
3676 This option replaces the old 'anonymize_headers' and the
3677 older 'http_anonymizer' option with something that is much
3678 more configurable. This new method creates a list of ACLs
3679 for each header, allowing you very fine-tuned header
3682 This option only applies to request headers, i.e., from the
3683 client to the server.
3685 You can only specify known headers for the header name.
3686 Other headers are reclassified as 'Other'. You can also
3687 refer to all the headers with 'All'.
3689 For example, to achieve the same behavior as the old
3690 'http_anonymizer standard' option, you should use:
3692 request_header_access From deny all
3693 request_header_access Referer deny all
3694 request_header_access Server deny all
3695 request_header_access User-Agent deny all
3696 request_header_access WWW-Authenticate deny all
3697 request_header_access Link deny all
3699 Or, to reproduce the old 'http_anonymizer paranoid' feature
3702 request_header_access Allow allow all
3703 request_header_access Authorization allow all
3704 request_header_access WWW-Authenticate allow all
3705 request_header_access Cache-Control allow all
3706 request_header_access Content-Encoding allow all
3707 request_header_access Content-Length allow all
3708 request_header_access Content-Type allow all
3709 request_header_access Date allow all
3710 request_header_access Expires allow all
3711 request_header_access Host allow all
3712 request_header_access If-Modified-Since allow all
3713 request_header_access Last-Modified allow all
3714 request_header_access Location allow all
3715 request_header_access Pragma allow all
3716 request_header_access Accept allow all
3717 request_header_access Accept-Charset allow all
3718 request_header_access Accept-Encoding allow all
3719 request_header_access Accept-Language allow all
3720 request_header_access Content-Language allow all
3721 request_header_access Mime-Version allow all
3722 request_header_access Retry-After allow all
3723 request_header_access Title allow all
3724 request_header_access Connection allow all
3725 request_header_access Proxy-Connection allow all
3726 request_header_access All deny all
3728 although many of those are HTTP reply headers, and so should be
3729 controlled with the reply_header_access directive.
3731 By default, all headers are allowed (no anonymizing is
3735 NAME: reply_header_access
3736 IFDEF: HTTP_VIOLATIONS
3737 TYPE: http_header_access[]
3738 LOC: Config.reply_header_access
3741 Usage: reply_header_access header_name allow|deny [!]aclname ...
3743 WARNING: Doing this VIOLATES the HTTP standard. Enabling
3744 this feature could make you liable for problems which it
3747 This option only applies to reply headers, i.e., from the
3748 server to the client.
3750 This is the same as request_header_access, but in the other
3753 This option replaces the old 'anonymize_headers' and the
3754 older 'http_anonymizer' option with something that is much
3755 more configurable. This new method creates a list of ACLs
3756 for each header, allowing you very fine-tuned header
3759 You can only specify known headers for the header name.
3760 Other headers are reclassified as 'Other'. You can also
3761 refer to all the headers with 'All'.
3763 For example, to achieve the same behavior as the old
3764 'http_anonymizer standard' option, you should use:
3766 reply_header_access From deny all
3767 reply_header_access Referer deny all
3768 reply_header_access Server deny all
3769 reply_header_access User-Agent deny all
3770 reply_header_access WWW-Authenticate deny all
3771 reply_header_access Link deny all
3773 Or, to reproduce the old 'http_anonymizer paranoid' feature
3776 reply_header_access Allow allow all
3777 reply_header_access Authorization allow all
3778 reply_header_access WWW-Authenticate allow all
3779 reply_header_access Cache-Control allow all
3780 reply_header_access Content-Encoding allow all
3781 reply_header_access Content-Length allow all
3782 reply_header_access Content-Type allow all
3783 reply_header_access Date allow all
3784 reply_header_access Expires allow all
3785 reply_header_access Host allow all
3786 reply_header_access If-Modified-Since allow all
3787 reply_header_access Last-Modified allow all
3788 reply_header_access Location allow all
3789 reply_header_access Pragma allow all
3790 reply_header_access Accept allow all
3791 reply_header_access Accept-Charset allow all
3792 reply_header_access Accept-Encoding allow all
3793 reply_header_access Accept-Language allow all
3794 reply_header_access Content-Language allow all
3795 reply_header_access Mime-Version allow all
3796 reply_header_access Retry-After allow all
3797 reply_header_access Title allow all
3798 reply_header_access Connection allow all
3799 reply_header_access Proxy-Connection allow all
3800 reply_header_access All deny all
3802 although the HTTP request headers won't be usefully controlled
3803 by this directive -- see request_header_access for details.
3805 By default, all headers are allowed (no anonymizing is
3809 NAME: header_replace
3810 IFDEF: HTTP_VIOLATIONS
3811 TYPE: http_header_replace[]
3812 LOC: Config.request_header_access
3815 Usage: header_replace header_name message
3816 Example: header_replace User-Agent Nutscrape/1.0 (CP/M; 8-bit)
3818 This option allows you to change the contents of headers
3819 denied with header_access above, by replacing them with
3820 some fixed string. This replaces the old fake_user_agent
3823 This only applies to request headers, not reply headers.
3825 By default, headers are removed if denied.
3828 NAME: icon_directory
3830 LOC: Config.icons.directory
3831 DEFAULT: @DEFAULT_ICON_DIR@
3833 Where the icons are stored. These are normally kept in
3837 NAME: global_internal_static
3839 LOC: Config.onoff.global_internal_static
3842 This directive controls is Squid should intercept all requests for
3843 /squid-internal-static/ no matter which host the URL is requesting
3844 (default on setting), or if nothing special should be done for
3845 such URLs (off setting). The purpose of this directive is to make
3846 icons etc work better in complex cache hierarchies where it may
3847 not always be possible for all corners in the cache mesh to reach
3848 the server generating a directory listing.
3851 NAME: short_icon_urls
3853 LOC: Config.icons.use_short_names
3856 If this is enabled Squid will use short URLs for icons.
3857 If disabled it will revert to the old behavior of including
3858 it's own name and port in the URL.
3860 If you run a complex cache hierarchy with a mix of Squid and
3861 other proxies you may need to disable this directive.
3864 NAME: error_directory
3866 LOC: Config.errorDirectory
3867 DEFAULT: @DEFAULT_ERROR_DIR@
3869 If you wish to create your own versions of the default
3870 (English) error files, either to customize them to suit your
3871 language or company copy the template English files to another
3872 directory and point this tag at them.
3875 NAME: maximum_single_addr_tries
3877 LOC: Config.retry.maxtries
3880 This sets the maximum number of connection attempts for a
3881 host that only has one address (for multiple-address hosts,
3882 each address is tried once).
3884 The default value is one attempt, the (not recommended)
3885 maximum is 255 tries. A warning message will be generated
3886 if it is set to a value greater than ten.
3888 Note: This is in addition to the request re-forwarding which
3889 takes place if Squid fails to get a satisfying response.
3892 NAME: retry_on_error
3894 LOC: Config.retry.onerror
3897 If set to on Squid will automatically retry requests when
3898 receiving an error response. This is mainly useful if you
3899 are in a complex cache hierarchy to work around access
3905 LOC: Config.Port.snmp
3909 Squid can now serve statistics and status information via SNMP.
3910 By default it listens to port 3401 on the machine. If you don't
3911 wish to use SNMP, set this to "0".
3913 Note: If you want Squid to use parents for all requests see
3914 the never_direct directive. prefer_direct only modifies how Squid
3915 acts on cachable requests.
3920 LOC: Config.accessList.snmp
3922 DEFAULT_IF_NONE: deny all
3925 Allowing or denying access to the SNMP port.
3927 All access to the agent is denied by default.
3930 snmp_access allow|deny [!]aclname ...
3933 snmp_access allow snmppublic localhost
3934 snmp_access deny all
3937 NAME: snmp_incoming_address
3939 LOC: Config.Addrs.snmp_incoming
3943 NAME: snmp_outgoing_address
3945 LOC: Config.Addrs.snmp_outgoing
3946 DEFAULT: 255.255.255.255
3949 Just like 'udp_incoming_address' above, but for the SNMP port.
3951 snmp_incoming_address is used for the SNMP socket receiving
3952 messages from SNMP agents.
3953 snmp_outgoing_address is used for SNMP packets returned to SNMP
3956 The default snmp_incoming_address (0.0.0.0) is to listen on all
3957 available network interfaces.
3959 If snmp_outgoing_address is set to 255.255.255.255 (the default)
3960 it will use the same socket as snmp_incoming_address. Only
3961 change this if you want to have SNMP replies sent using another
3962 address than where this Squid listens for SNMP queries.
3964 NOTE, snmp_incoming_address and snmp_outgoing_address can not have
3965 the same value since they both use port 3401.
3968 NAME: as_whois_server
3970 LOC: Config.as_whois_server
3971 DEFAULT: whois.ra.net
3972 DEFAULT_IF_NONE: whois.ra.net
3974 WHOIS server to query for AS numbers. NOTE: AS numbers are
3975 queried only when Squid starts up, not for every request.
3980 LOC: Config.Wccp.router
3984 Use this option to define your WCCP ``home'' router for
3985 Squid. Setting the 'wccp_router' to 0.0.0.0 (the default)
3991 LOC: Config.Wccp.version
3995 According to some users, Cisco IOS 11.2 only supports WCCP
3996 version 3. If you're using that version of IOS, change
4000 NAME: wccp_incoming_address
4002 LOC: Config.Wccp.incoming
4006 NAME: wccp_outgoing_address
4008 LOC: Config.Wccp.outgoing
4009 DEFAULT: 255.255.255.255
4012 wccp_incoming_address Use this option if you require WCCP
4013 messages to be received on only one
4014 interface. Do NOT use this option if
4015 you're unsure how many interfaces you
4016 have, or if you know you have only one
4019 wccp_outgoing_address Use this option if you require WCCP
4020 messages to be sent out on only one
4021 interface. Do NOT use this option if
4022 you're unsure how many interfaces you
4023 have, or if you know you have only one
4026 The default behavior is to not bind to any specific address.
4028 NOTE, wccp_incoming_address and wccp_outgoing_address can not have
4029 the same value since they both use port 2048.
4034 DELAY POOL PARAMETERS (all require DELAY_POOLS compilation option)
4035 -----------------------------------------------------------------------------
4039 TYPE: delay_pool_count
4044 This represents the number of delay pools to be used. For example,
4045 if you have one class 2 delay pool and one class 3 delays pool, you
4046 have a total of 2 delay pools.
4050 TYPE: delay_pool_class
4055 This defines the class of each delay pool. There must be exactly one
4056 delay_class line for each delay pool. For example, to define two
4057 delay pools, one of class 2 and one of class 3, the settings above
4061 delay_pools 4 # 4 delay pools
4062 delay_class 1 2 # pool 1 is a class 2 pool
4063 delay_class 2 3 # pool 2 is a class 3 pool
4064 delay_class 3 4 # pool 3 is a class 4 pool
4065 delay_class 4 5 # pool 4 is a class 5 pool
4067 The delay pool classes are:
4069 class 1 Everything is limited by a single aggregate
4072 class 2 Everything is limited by a single aggregate
4073 bucket as well as an "individual" bucket chosen
4074 from bits 25 through 32 of the IP address.
4076 class 3 Everything is limited by a single aggregate
4077 bucket as well as a "network" bucket chosen
4078 from bits 17 through 24 of the IP address and a
4079 "individual" bucket chosen from bits 17 through
4080 32 of the IP address.
4082 class 4 Everything in a class 3 delay pool, with an
4083 additional limit on a per user basis. This
4084 only takes effect if the username is established
4085 in advance - by forcing authentication in your
4088 class 5 Requests are grouped according their tag (see
4089 external_acl's tag= reply).
4091 NOTE: If an IP address is a.b.c.d
4092 -> bits 25 through 32 are "d"
4093 -> bits 17 through 24 are "c"
4094 -> bits 17 through 32 are "c * 256 + d"
4098 TYPE: delay_pool_access
4103 This is used to determine which delay pool a request falls into.
4105 delay_access is sorted per pool and the matching starts with pool 1,
4106 then pool 2, ..., and finally pool N. The first delay pool where the
4107 request is allowed is selected for the request. If it does not allow
4108 the request to any pool then the request is not delayed (default).
4110 For example, if you want some_big_clients in delay
4111 pool 1 and lotsa_little_clients in delay pool 2:
4114 delay_access 1 allow some_big_clients
4115 delay_access 1 deny all
4116 delay_access 2 allow lotsa_little_clients
4117 delay_access 2 deny all
4118 delay_access 3 allow authenticated_clients
4121 NAME: delay_parameters
4122 TYPE: delay_pool_rates
4127 This defines the parameters for a delay pool. Each delay pool has
4128 a number of "buckets" associated with it, as explained in the
4129 description of delay_class. For a class 1 delay pool, the syntax is:
4131 delay_parameters pool aggregate
4133 For a class 2 delay pool:
4135 delay_parameters pool aggregate individual
4137 For a class 3 delay pool:
4139 delay_parameters pool aggregate network individual
4141 For a class 4 delay pool:
4143 delay_parameters pool aggregate network individual user
4145 For a class 5 delay pool:
4147 delay_parameters pool tag
4149 The variables here are:
4151 pool a pool number - ie, a number between 1 and the
4152 number specified in delay_pools as used in
4155 aggregate the "delay parameters" for the aggregate bucket
4158 individual the "delay parameters" for the individual
4159 buckets (class 2, 3).
4161 network the "delay parameters" for the network buckets
4164 user the delay parameters for the user buckets
4167 tag the delay parameters for the tag buckets
4170 A pair of delay parameters is written restore/maximum, where restore is
4171 the number of bytes (not bits - modem and network speeds are usually
4172 quoted in bits) per second placed into the bucket, and maximum is the
4173 maximum number of bytes which can be in the bucket at any time.
4175 For example, if delay pool number 1 is a class 2 delay pool as in the
4176 above example, and is being used to strictly limit each host to 64kbps
4177 (plus overheads), with no overall limit, the line is:
4179 delay_parameters 1 -1/-1 8000/8000
4181 Note that the figure -1 is used to represent "unlimited".
4183 And, if delay pool number 2 is a class 3 delay pool as in the above
4184 example, and you want to limit it to a total of 256kbps (strict limit)
4185 with each 8-bit network permitted 64kbps (strict limit) and each
4186 individual host permitted 4800bps with a bucket maximum size of 64kb
4187 to permit a decent web page to be downloaded at a decent speed
4188 (if the network is not being limited due to overuse) but slow down
4189 large downloads more significantly:
4191 delay_parameters 2 32000/32000 8000/8000 600/8000
4193 There must be one delay_parameters line for each delay pool.
4195 Finally, for a class 4 delay pool as in the example - each user will
4196 be limited to 128Kb no matter how many workstations they are logged into.:
4198 delay_parameters 4 32000/32000 8000/8000 600/64000 16000/16000
4201 NAME: delay_initial_bucket_level
4202 COMMENT: (percent, 0-100)
4206 LOC: Config.Delay.initial
4208 The initial bucket percentage is used to determine how much is put
4209 in each bucket when squid starts, is reconfigured, or first notices
4210 a host accessing it (in class 2 and class 3, individual hosts and
4211 networks only have buckets associated with them once they have been
4215 NAME: incoming_icp_average
4218 LOC: Config.comm_incoming.icp_average
4221 NAME: incoming_http_average
4224 LOC: Config.comm_incoming.http_average
4227 NAME: incoming_dns_average
4230 LOC: Config.comm_incoming.dns_average
4233 NAME: min_icp_poll_cnt
4236 LOC: Config.comm_incoming.icp_min_poll
4239 NAME: min_dns_poll_cnt
4242 LOC: Config.comm_incoming.dns_min_poll
4245 NAME: min_http_poll_cnt
4248 LOC: Config.comm_incoming.http_min_poll
4250 Heavy voodoo here. I can't even believe you are reading this.
4251 Are you crazy? Don't even think about adjusting these unless
4252 you understand the algorithms in comm_select.c first!
4255 NAME: max_open_disk_fds
4257 LOC: Config.max_open_disk_fds
4260 To avoid having disk as the I/O bottleneck Squid can optionally
4261 bypass the on-disk cache if more than this amount of disk file
4262 descriptors are open.
4264 A value of 0 indicates no limit.
4269 LOC: Config.onoff.offline
4272 Enable this option and Squid will never try to validate cached
4276 NAME: uri_whitespace
4277 TYPE: uri_whitespace
4278 LOC: Config.uri_whitespace
4281 What to do with requests that have whitespace characters in the
4284 strip: The whitespace characters are stripped out of the URL.
4285 This is the behavior recommended by RFC2396.
4286 deny: The request is denied. The user receives an "Invalid
4288 allow: The request is allowed and the URI is not changed. The
4289 whitespace characters remain in the URI. Note the
4290 whitespace is passed to redirector processes if they
4292 encode: The request is allowed and the whitespace characters are
4293 encoded according to RFC1738. This could be considered
4294 a violation of the HTTP/1.1
4295 RFC because proxies are not allowed to rewrite URI's.
4296 chop: The request is allowed and the URI is chopped at the
4297 first whitespace. This might also be considered a
4304 LOC: Config.accessList.brokenPosts
4306 A list of ACL elements which, if matched, causes Squid to send
4307 an extra CRLF pair after the body of a PUT/POST request.
4309 Some HTTP servers has broken implementations of PUT/POST,
4310 and rely on an extra CRLF pair sent by some WWW clients.
4312 Quote from RFC 2068 section 4.1 on this matter:
4314 Note: certain buggy HTTP/1.0 client implementations generate an
4315 extra CRLF's after a POST request. To restate what is explicitly
4316 forbidden by the BNF, an HTTP/1.1 client must not preface or follow
4317 a request with an extra CRLF.
4320 acl buggy_server url_regex ^http://....
4321 broken_posts allow buggy_server
4324 NAME: mcast_miss_addr
4325 IFDEF: MULTICAST_MISS_STREAM
4327 LOC: Config.mcast_miss.addr
4328 DEFAULT: 255.255.255.255
4330 If you enable this option, every "cache miss" URL will
4331 be sent out on the specified multicast address.
4333 Do not enable this option unless you are are absolutely
4334 certain you understand what you are doing.
4337 NAME: mcast_miss_ttl
4338 IFDEF: MULTICAST_MISS_STREAM
4340 LOC: Config.mcast_miss.ttl
4343 This is the time-to-live value for packets multicasted
4344 when multicasting off cache miss URLs is enabled. By
4345 default this is set to 'site scope', i.e. 16.
4348 NAME: mcast_miss_port
4349 IFDEF: MULTICAST_MISS_STREAM
4351 LOC: Config.mcast_miss.port
4354 This is the port number to be used in conjunction with
4358 NAME: mcast_miss_encode_key
4359 IFDEF: MULTICAST_MISS_STREAM
4361 LOC: Config.mcast_miss.encode_key
4362 DEFAULT: XXXXXXXXXXXXXXXX
4364 The URLs that are sent in the multicast miss stream are
4365 encrypted. This is the encryption key.
4368 NAME: nonhierarchical_direct
4370 LOC: Config.onoff.nonhierarchical_direct
4373 By default, Squid will send any non-hierarchical requests
4374 (matching hierarchy_stoplist or not cachable request type) direct
4377 If you set this to off, Squid will prefer to send these
4378 requests to parents.
4380 Note that in most configurations, by turning this off you will only
4381 add latency to these request without any improvement in global hit
4384 If you are inside an firewall see never_direct instead of
4390 LOC: Config.onoff.prefer_direct
4393 Normally Squid tries to use parents for most requests. If you for some
4394 reason like it to first try going direct and only use a parent if
4395 going direct fails set this to on.
4397 By combining nonhierarchical_direct off and prefer_direct on you
4398 can set up Squid to use a parent as a backup path if going direct
4402 NAME: strip_query_terms
4404 LOC: Config.onoff.strip_query_terms
4407 By default, Squid strips query terms from requested URLs before
4408 logging. This protects your user's privacy.
4413 LOC: Config.coredump_dir
4415 DEFAULT_IF_NONE: none
4417 By default Squid leaves core files in the directory from where
4418 it was started. If you set 'coredump_dir' to a directory
4419 that exists, Squid will chdir() to that directory at startup
4420 and coredump files will be left there.
4423 # Leave coredumps in the first cache dir
4424 coredump_dir @DEFAULT_SWAP_DIR@
4428 NAME: redirector_bypass
4430 LOC: Config.onoff.redirector_bypass
4433 When this is 'on', a request will not go through the
4434 redirector if all redirectors are busy. If this is 'off'
4435 and the redirector queue grows too large, Squid will exit
4436 with a FATAL error and ask you to increase the number of
4437 redirectors. You should only enable this if the redirectors
4438 are not critical to your caching system. If you use
4439 redirectors for access control, and you enable this option,
4440 users may have access to pages they should not
4441 be allowed to request.
4444 NAME: ignore_unknown_nameservers
4446 LOC: Config.onoff.ignore_unknown_nameservers
4449 By default Squid checks that DNS responses are received
4450 from the same IP addresses they are sent to. If they
4451 don't match, Squid ignores the response and writes a warning
4452 message to cache.log. You can allow responses from unknown
4453 nameservers by setting this option to 'off'.
4456 NAME: digest_generation
4457 IFDEF: USE_CACHE_DIGESTS
4459 LOC: Config.onoff.digest_generation
4462 This controls whether the server will generate a Cache Digest
4463 of its contents. By default, Cache Digest generation is
4464 enabled if Squid is compiled with USE_CACHE_DIGESTS defined.
4467 NAME: digest_bits_per_entry
4468 IFDEF: USE_CACHE_DIGESTS
4470 LOC: Config.digest.bits_per_entry
4473 This is the number of bits of the server's Cache Digest which
4474 will be associated with the Digest entry for a given HTTP
4475 Method and URL (public key) combination. The default is 5.
4478 NAME: digest_rebuild_period
4479 IFDEF: USE_CACHE_DIGESTS
4482 LOC: Config.digest.rebuild_period
4485 This is the number of seconds between Cache Digest rebuilds.
4488 NAME: digest_rewrite_period
4490 IFDEF: USE_CACHE_DIGESTS
4492 LOC: Config.digest.rewrite_period
4495 This is the number of seconds between Cache Digest writes to
4499 NAME: digest_swapout_chunk_size
4502 IFDEF: USE_CACHE_DIGESTS
4503 LOC: Config.digest.swapout_chunk_size
4506 This is the number of bytes of the Cache Digest to write to
4507 disk at a time. It defaults to 4096 bytes (4KB), the Squid
4511 NAME: digest_rebuild_chunk_percentage
4512 COMMENT: (percent, 0-100)
4513 IFDEF: USE_CACHE_DIGESTS
4515 LOC: Config.digest.rebuild_chunk_percentage
4518 This is the percentage of the Cache Digest to be scanned at a
4519 time. By default it is set to 10% of the Cache Digest.
4524 LOC: Config.chroot_dir
4527 Use this to have Squid do a chroot() while initializing. This
4528 also causes Squid to fully drop root privileges after
4529 initializing. This means, for example, if you use a HTTP
4530 port less than 1024 and try to reconfigure, you will get an
4534 NAME: client_persistent_connections
4536 LOC: Config.onoff.client_pconns
4540 NAME: server_persistent_connections
4542 LOC: Config.onoff.server_pconns
4545 Persistent connection support for clients and servers. By
4546 default, Squid uses persistent connections (when allowed)
4547 with its clients and servers. You can use these options to
4548 disable persistent connections with clients and/or servers.
4551 NAME: balance_on_multiple_ip
4553 LOC: Config.onoff.balance_on_multiple_ip
4556 Some load balancing servers based on round robin DNS have been
4557 found not to preserve user session state across requests
4558 to different IP addresses.
4560 By default Squid rotates IP's per request. By disabling
4561 this directive only connection failure triggers rotation.
4564 NAME: detect_broken_pconn
4566 LOC: Config.onoff.detect_broken_server_pconns
4569 Some servers have been found to incorrectly signal the use
4570 of HTTP/1.0 persistent connections even on replies not
4571 compatible, causing significant delays. This server problem
4572 has mostly been seen on redirects.
4574 By enabling this directive Squid attempts to detect such
4575 broken replies and automatically assume the reply is finished
4576 after 10 seconds timeout.
4579 NAME: pipeline_prefetch
4581 LOC: Config.onoff.pipeline_prefetch
4584 To boost the performance of pipelined requests to closer
4585 match that of a non-proxied environment Squid can try to fetch
4586 up to two requests in parallel from a pipeline.
4588 Defaults to off for bandwidth management and access logging
4592 NAME: extension_methods
4594 LOC: Config.ext_methods
4597 Squid only knows about standardized HTTP request methods.
4598 You can add up to 20 additional "extension" methods here.
4601 NAME: request_entities
4603 LOC: Config.onoff.request_entities
4606 Squid defaults to deny GET and HEAD requests with request entities,
4607 as the meaning of such requests are undefined in the HTTP standard
4608 even if not explicitly forbidden.
4610 Set this directive to on if you have clients which insists
4611 on sending request entities in GET or HEAD requests.
4614 NAME: high_response_time_warning
4617 LOC: Config.warnings.high_rptm
4620 If the one-minute median response time exceeds this value,
4621 Squid prints a WARNING with debug level 0 to get the
4622 administrators attention. The value is in milliseconds.
4625 NAME: high_page_fault_warning
4627 LOC: Config.warnings.high_pf
4630 If the one-minute average page fault rate exceeds this
4631 value, Squid prints a WARNING with debug level 0 to get
4632 the administrators attention. The value is in page faults
4636 NAME: high_memory_warning
4638 LOC: Config.warnings.high_memory
4641 If the memory usage (as determined by mallinfo) exceeds
4642 value, Squid prints a WARNING with debug level 0 to get
4643 the administrators attention.
4646 NAME: store_dir_select_algorithm
4648 LOC: Config.store_dir_select_algorithm
4651 Set this to 'round-robin' as an alternative.
4658 LOC: Config.Log.forward
4660 Logs the server-side requests.
4662 This is currently work in progress.
4668 LOC: Config.onoff.ie_refresh
4671 Microsoft Internet Explorer up until version 5.5 Service
4672 Pack 1 has an issue with transparent proxies, wherein it
4673 is impossible to force a refresh. Turning this on provides
4674 a partial fix to the problem, by causing all IMS-REFRESH
4675 requests from older IE versions to check the origin server
4676 for fresh content. This reduces hit ratio by some amount
4677 (~10% in my experience), but allows users to actually get
4678 fresh content when they want it. Note because Squid
4679 cannot tell if the user is using 5.5 or 5.5SP1, the behavior
4680 of 5.5 is unchanged from old versions of Squid (i.e. a
4681 forced refresh is impossible). Newer versions of IE will,
4682 hopefully, continue to have the new behavior and will be
4683 handled based on that assumption. This option defaults to
4684 the old Squid behavior, which is better for hit ratios but
4685 worse for clients using IE, if they need to be able to
4686 force fresh content.
4689 NAME: vary_ignore_expire
4692 LOC: Config.onoff.vary_ignore_expire
4695 Many HTTP servers supporting Vary gives such objects
4696 immediate expiry time with no cache-control header
4697 when requested by a HTTP/1.0 client. This option
4698 enables Squid to ignore such expiry times until
4699 HTTP/1.1 is fully implemented.
4700 WARNING: This may eventually cause some varying
4701 objects not intended for caching to get cached.
4704 NAME: sleep_after_fork
4705 COMMENT: (microseconds)
4707 LOC: Config.sleep_after_fork
4710 When this is set to a non-zero value, the main Squid process
4711 sleeps the specified number of microseconds after a fork()
4712 system call. This sleep may help the situation where your
4713 system reports fork() failures due to lack of (virtual)
4714 memory. Note, however, if you have a lot of child
4715 processes, these sleep delays will add up and your
4716 Squid will not service requests for some amount of time
4717 until all the child processes have been started.
4720 NAME: minimum_expiry_time
4723 LOC: Config.minimum_expiry_time
4726 The minimum caching time according to (Expires - Date)
4727 Headers Squid honors if the object can't be revalidated
4728 defaults to 60 seconds. In reverse proxy enorinments it
4729 might be desirable to honor shorter object lifetimes. It
4730 is most likely better to make your server return a
4731 meaningful Last-Modified header however. In ESI environments
4732 where page fragments often have short lifetimes, this will
4733 often be best set to 0.
4736 NAME: relaxed_header_parser
4737 COMMENT: on|off|warn
4739 LOC: Config.onoff.relaxed_header_parser
4742 In the default "on" setting Squid accepts certain forms
4743 of non-compliant HTTP messages where it is unambiguous
4744 what the sending application intended even if the message
4745 is not correctly formatted. The messages is then normalized
4746 to the correct form when forwarded by Squid.
4748 If set to "warn" then a warning will be emitted in cache.log
4749 each time such HTTP error is encountered.
4751 If set to "off" then such HTTP errors will cause the request
4752 or response to be rejected.
4757 -----------------------------------------------------------------------------
4764 LOC: TheICAPConfig.onoff
4767 If you want to enable the ICAP module support, set this to on.
4770 NAME: icap_preview_enable
4774 LOC: TheICAPConfig.preview_enable
4777 Set this to 'on' if you want to enable the ICAP preview
4781 NAME: icap_preview_size
4784 LOC: TheICAPConfig.preview_size
4787 The default size of preview data to be sent to the ICAP server.
4788 -1 means no preview. This value might be overwritten on a per server
4789 basis by OPTIONS requests.
4792 NAME: icap_persistent_connections
4796 LOC: TheICAPConfig.reuse_connections
4799 Whether or not Squid should use persistent connections to
4803 NAME: icap_send_client_ip
4807 LOC: TheICAPConfig.send_client_ip
4810 This adds the header "X-Client-IP" to ICAP requests.
4813 NAME: icap_send_client_username
4817 LOC: TheICAPConfig.send_client_username
4820 This adds the header "X-Client-Username" to ICAP requests
4821 if proxy access is authentified.
4825 TYPE: icap_service_type
4830 Defines a single ICAP service
4832 icap_service servicename vectoring_point bypass service_url
4834 vectoring_point = reqmod_precache|reqmod_postcache|respmod_precache|respmod_postcache
4835 This specifies at which point of request processing the ICAP
4836 service should be plugged in.
4838 If set to 1 and the ICAP server cannot be reached, the request will go
4839 through without being processed by an ICAP server
4840 service_url = icap://servername:port/service
4842 Note: reqmod_precache and respmod_postcache is not yet implemented
4845 icap_service service_1 reqmod_precache 0 icap://icap1.mydomain.net:1344/reqmod
4846 icap_service service_2 respmod_precache 0 icap://icap2.mydomain.net:1344/respmod
4850 TYPE: icap_class_type
4855 Defines an ICAP service chain. If there are multiple services per
4856 vectoring point, they are processed in the specified order.
4858 icap_class classname servicename...
4861 icap_class class_1 service_1 service_2
4862 icap class class_2 service_1 service_3
4866 TYPE: icap_access_type
4871 Redirects a request through an ICAP service class, depending
4874 icap_access classname allow|deny [!]aclname...
4876 The icap_access statements are processed in the order they appear in
4877 this configuration file. If an access list matches, the processing stops.
4878 For an "allow" rule, the specified class is used for the request. A "deny"
4879 rule simply stops processing without using the class. You can also use the
4880 special classname "None".
4882 For backward compatibility, it is also possible to use services
4885 icap_access class_1 allow all