3 # $Id: cf.data.pre,v 1.396 2005/09/25 20:25:55 hno 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
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).
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: %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 ../auth_modules/NCSA directory and
1755 Then, set this line to something like
1757 auth_param basic program @DEFAULT_PREFIX@/bin/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.
1869 === NTLM scheme options follow ===
1872 Specify the command for the external NTLM authenticator.
1873 Such a program reads exchanged NTLMSSP packets with
1874 the browser via Squid until authentication is completed.
1875 If you use an NTLM authenticator, make sure you have 1 acl
1876 of type proxy_auth. By default, the NTLM authenticator_program
1879 auth_param ntlm program @DEFAULT_PREFIX@/bin/ntlm_auth
1881 "children" numberofchildren
1882 The number of authenticator processes to spawn (no default).
1883 If you start too few Squid will have to wait for them to
1884 process a backlog of credential verifications, slowing it
1885 down. When credential verifications are done via a (slow)
1886 network you are likely to need lots of authenticator
1888 auth_param ntlm children 5
1890 "max_challenge_reuses" number
1891 The maximum number of times a challenge given by a ntlm
1892 authentication helper can be reused. Increasing this number
1893 increases your exposure to replay attacks on your network.
1894 0 means use the challenge only once. (disable challenge
1895 caching) See max_ntlm_challenge_lifetime for more information.
1896 auth_param ntlm max_challenge_reuses 0
1898 "max_challenge_lifetime" timespan
1899 The maximum time period a ntlm challenge is reused
1900 over. The actual period will be the minimum of this time
1901 AND the number of reused challenges.
1902 auth_param ntlm max_challenge_lifetime 2 minutes
1905 #Recommended minimum configuration:
1906 #auth_param digest program <uncomment and complete this line>
1907 #auth_param digest children 5
1908 #auth_param digest realm Squid proxy-caching web server
1909 #auth_param digest nonce_garbage_interval 5 minutes
1910 #auth_param digest nonce_max_duration 30 minutes
1911 #auth_param digest nonce_max_count 50
1912 #auth_param ntlm program <uncomment and complete this line to activate>
1913 #auth_param ntlm children 5
1914 #auth_param ntlm max_challenge_reuses 0
1915 #auth_param ntlm max_challenge_lifetime 2 minutes
1916 #auth_param basic program <uncomment and complete this line>
1917 auth_param basic children 5
1918 auth_param basic realm Squid proxy-caching web server
1919 auth_param basic credentialsttl 2 hours
1923 NAME: authenticate_cache_garbage_interval
1926 LOC: Config.authenticateGCInterval
1928 The time period between garbage collection across the
1929 username cache. This is a tradeoff between memory utilization
1930 (long intervals - say 2 days) and CPU (short intervals -
1931 say 1 minute). Only change if you have good reason to.
1934 NAME: authenticate_ttl
1937 LOC: Config.authenticateTTL
1939 The time a user & their credentials stay in the logged in
1940 user cache since their last request. When the garbage
1941 interval passes, all user credentials that have passed their
1942 TTL are removed from memory.
1945 NAME: authenticate_ip_ttl
1947 LOC: Config.authenticateIpTTL
1950 If you use proxy authentication and the 'max_user_ip' ACL,
1951 this directive controls how long Squid remembers the IP
1952 addresses associated with each user. Use a small value
1953 (e.g., 60 seconds) if your users might change addresses
1954 quickly, as is the case with dialups. You might be safe
1955 using a larger value (e.g., 2 hours) in a corporate LAN
1956 environment with relatively static address assignments.
1959 NAME: external_acl_type
1960 TYPE: externalAclHelper
1961 LOC: Config.externalAclHelperList
1964 This option defines external acl classes using a helper program
1965 to look up the status
1967 external_acl_type name [options] FORMAT.. /path/to/helper [helper arguments..]
1971 ttl=n TTL in seconds for cached results (defaults to 3600
1974 TTL for cached negative lookups (default same
1976 children=n Number of acl helper processes spawn to service
1977 external acl lookups of this type.
1978 concurrency=n concurrency level per process. Use 0 for old style
1979 helpers who can only process a single request at a
1981 cache=n result cache size, 0 is unbounded (default)
1982 grace=n Percentage remaining of TTL where a refresh of a
1983 cached entry should be initiated without needing to
1984 wait for a new reply. (default 0 for no grace period)
1985 protocol=2.5 Compatibility mode for Squid-2.5 external acl helpers
1987 FORMAT specifications
1989 %LOGIN Authenticated user login name
1990 %EXT_USER Username from external acl
1991 %IDENT Ident user name
1993 %SRCPORT Client source port
1995 %PROTO Requested protocol
1996 %PORT Requested port
1997 %PATH Requested URL path
1998 %METHOD Request method
1999 %MYADDR Squid interface address
2000 %MYPORT Squid http_port number
2001 %USER_CERT SSL User certificate in PEM format
2002 %USER_CERTCHAIN SSL User certificate chain in PEM format
2003 %USER_CERT_xx SSL User certificate subject attribute xx
2004 %USER_CA_xx SSL User certificate issuer attribute xx
2005 %{Header} HTTP request header
2006 %{Hdr:member} HTTP request header list member
2008 HTTP request header list member using ; as
2009 list separator. ; can be any non-alphanumeric
2012 In addition, any string specified in the referencing acl will
2013 also be included in the helper request line, after the specified
2014 formats (see the "acl external" directive)
2016 The helper receives lines per the above format specification,
2017 and returns lines starting with OK or ERR indicating the validity
2018 of the request and optionally followed by additional keywords with
2019 more details. To protect from odd characters the data is URL
2022 General result syntax:
2024 OK/ERR keyword=value ...
2028 user= The users name (login)
2029 password= The users password (for login= cache_peer option)
2030 message= Message describing the reason. Available as %o
2032 tag= Apply a tag to a request (for both ERR and OK results)
2033 Only sets a tag, does not alter existing tags.
2034 log= String to be logged in access.log. Available as
2035 %ea in logformat specifications
2037 Keyword values need to be URL escaped if they may contain
2038 contain whitespace or quotes.
2040 In Squid-2.5 compatibility mode quoting using " and \ is used
2041 instead of URL escaping.
2045 OPTIONS FOR TUNING THE CACHE
2046 -----------------------------------------------------------------------------
2049 NAME: wais_relay_host
2052 LOC: Config.Wais.relayHost
2055 NAME: wais_relay_port
2058 LOC: Config.Wais.relayPort
2060 Relay WAIS request to host (1st arg) at port (2 arg).
2064 NAME: request_header_max_size
2068 LOC: Config.maxRequestHeaderSize
2070 This specifies the maximum size for HTTP headers in a request.
2071 Request headers are usually relatively small (about 512 bytes).
2072 Placing a limit on the request header size will catch certain
2073 bugs (for example with persistent connections) and possibly
2074 buffer-overflow or denial-of-service attacks.
2077 NAME: request_body_max_size
2081 LOC: Config.maxRequestBodySize
2083 This specifies the maximum size for an HTTP request body.
2084 In other words, the maximum size of a PUT/POST request.
2085 A user who attempts to send a request with a body larger
2086 than this limit receives an "Invalid Request" error message.
2087 If you set this parameter to a zero (the default), there will
2088 be no limit imposed.
2091 NAME: refresh_pattern
2092 TYPE: refreshpattern
2096 usage: refresh_pattern [-i] regex min percent max [options]
2098 By default, regular expressions are CASE-SENSITIVE. To make
2099 them case-insensitive, use the -i option.
2101 'Min' is the time (in minutes) an object without an explicit
2102 expiry time should be considered fresh. The recommended
2103 value is 0, any higher values may cause dynamic applications
2104 to be erroneously cached unless the application designer
2105 has taken the appropriate actions.
2107 'Percent' is a percentage of the objects age (time since last
2108 modification age) an object without explicit expiry time
2109 will be considered fresh.
2111 'Max' is an upper limit on how long objects without an explicit
2112 expiry time will be considered fresh.
2114 options: override-expire
2124 override-expire enforces min age even if the server
2125 sent a Expires: header. Doing this VIOLATES the HTTP
2126 standard. Enabling this feature could make you liable
2127 for problems which it causes.
2129 override-lastmod enforces min age even on objects
2130 that were modified recently.
2132 reload-into-ims changes client no-cache or ``reload''
2133 to If-Modified-Since requests. Doing this VIOLATES the
2134 HTTP standard. Enabling this feature could make you
2135 liable for problems which it causes.
2137 ignore-reload ignores a client no-cache or ``reload''
2138 header. Doing this VIOLATES the HTTP standard. Enabling
2139 this feature could make you liable for problems which
2142 ignore-no-cache ignores any ``Pragma: no-cache'' and
2143 ``Cache-control: no-cache'' headers received from a server.
2144 The HTTP RFC never allows the use of this (Pragma) header
2145 from a server, only a client, though plenty of servers
2148 ignore-no-store ignores any ``Cache-control: no-store''
2149 headers received from a server. Doing this VIOLATES
2150 the HTTP standard. Enabling this feature could make you
2151 liable for problems which it causes.
2153 ignore-private ignores any ``Cache-control: private''
2154 headers received from a server. Doing this VIOLATES
2155 the HTTP standard. Enabling this feature could make you
2156 liable for problems which it causes.
2158 ignore-auth caches responses to requests with authorization,
2159 irrespective of ``Cache-control'' headers received from
2160 a server. Doing this VIOLATES the HTTP standard. Enabling
2161 this feature could make you liable for problems which
2164 refresh-ims causes squid to contact the origin server
2165 when a client issues an If-Modified-Since request. This
2166 ensures that the client will receive an updated version
2167 if one is available.
2169 Basically a cached object is:
2171 FRESH if expires < now, else STALE
2173 FRESH if lm-factor < percent, else STALE
2177 The refresh_pattern lines are checked in the order listed here.
2178 The first entry which matches is used. If none of the entries
2179 match the default will be used.
2181 Note, you must uncomment all the default lines if you want
2182 to change one. The default setting is only active if none is
2187 refresh_pattern ^ftp: 1440 20% 10080
2188 refresh_pattern ^gopher: 1440 0% 1440
2189 refresh_pattern . 0 20% 4320
2193 NAME: quick_abort_min
2197 LOC: Config.quickAbort.min
2200 NAME: quick_abort_max
2204 LOC: Config.quickAbort.max
2207 NAME: quick_abort_pct
2211 LOC: Config.quickAbort.pct
2213 The cache by default continues downloading aborted requests
2214 which are almost completed (less than 16 KB remaining). This
2215 may be undesirable on slow (e.g. SLIP) links and/or very busy
2216 caches. Impatient users may tie up file descriptors and
2217 bandwidth by repeatedly requesting and immediately aborting
2220 When the user aborts a request, Squid will check the
2221 quick_abort values to the amount of data transfered until
2224 If the transfer has less than 'quick_abort_min' KB remaining,
2225 it will finish the retrieval.
2227 If the transfer has more than 'quick_abort_max' KB remaining,
2228 it will abort the retrieval.
2230 If more than 'quick_abort_pct' of the transfer has completed,
2231 it will finish the retrieval.
2233 If you do not want any retrieval to continue after the client
2234 has aborted, set both 'quick_abort_min' and 'quick_abort_max'
2237 If you want retrievals to always continue if they are being
2238 cached set 'quick_abort_min' to '-1 KB'.
2241 NAME: read_ahead_gap
2242 COMMENT: buffer-size
2244 LOC: Config.readAheadGap
2247 The amount of data the cache will buffer ahead of what has been
2248 sent to the client when retrieving an object from another server.
2254 LOC: Config.negativeTtl
2257 Time-to-Live (TTL) for failed requests. Certain types of
2258 failures (such as "connection refused" and "404 Not Found") are
2259 negatively-cached for a configurable amount of time. The
2260 default is 5 minutes. Note that this is different from
2261 negative caching of DNS lookups.
2265 NAME: positive_dns_ttl
2268 LOC: Config.positiveDnsTtl
2271 Time-to-Live (TTL) for positive caching of successful DNS lookups.
2272 Default is 6 hours (360 minutes). If you want to minimize the
2273 use of Squid's ipcache, set this to 1, not 0.
2277 NAME: negative_dns_ttl
2280 LOC: Config.negativeDnsTtl
2283 Time-to-Live (TTL) for negative caching of failed DNS lookups.
2286 NAME: range_offset_limit
2289 LOC: Config.rangeOffsetLimit
2292 Sets a upper limit on how far into the the file a Range request
2293 may be to cause Squid to prefetch the whole file. If beyond this
2294 limit Squid forwards the Range request as it is and the result
2297 This is to stop a far ahead range request (lets say start at 17MB)
2298 from making Squid fetch the whole object up to that point before
2299 sending anything to the client.
2301 A value of -1 causes Squid to always fetch the object from the
2302 beginning so it may cache the result. (2.0 style)
2304 A value of 0 causes Squid to never fetch more than the
2305 client requested. (default)
2311 -----------------------------------------------------------------------------
2314 NAME: forward_timeout
2317 LOC: Config.Timeout.forward
2320 This parameter specifies how long Squid should at most attempt in
2321 finding a forwarding path for the request before giving up.
2324 NAME: connect_timeout
2327 LOC: Config.Timeout.connect
2330 This parameter specifies how long to wait for the TCP connect to
2331 the requested server or peer to complete before Squid should
2332 attempt to find another path where to forward the request.
2335 NAME: peer_connect_timeout
2338 LOC: Config.Timeout.peer_connect
2341 This parameter specifies how long to wait for a pending TCP
2342 connection to a peer cache. The default is 30 seconds. You
2343 may also set different timeout values for individual neighbors
2344 with the 'connect-timeout' option on a 'cache_peer' line.
2350 LOC: Config.Timeout.read
2353 The read_timeout is applied on server-side connections. After
2354 each successful read(), the timeout will be extended by this
2355 amount. If no data is read again after this amount of time,
2356 the request is aborted and logged with ERR_READ_TIMEOUT. The
2357 default is 15 minutes.
2361 NAME: request_timeout
2363 LOC: Config.Timeout.request
2366 How long to wait for an HTTP request after initial
2367 connection establishment.
2371 NAME: persistent_request_timeout
2373 LOC: Config.Timeout.persistent_request
2376 How long to wait for the next HTTP request on a persistent
2377 connection after the previous request completes.
2381 NAME: client_lifetime
2384 LOC: Config.Timeout.lifetime
2387 The maximum amount of time a client (browser) is allowed to
2388 remain connected to the cache process. This protects the Cache
2389 from having a lot of sockets (and hence file descriptors) tied up
2390 in a CLOSE_WAIT state from remote clients that go away without
2391 properly shutting down (either because of a network failure or
2392 because of a poor client implementation). The default is one
2395 NOTE: The default value is intended to be much larger than any
2396 client would ever need to be connected to your cache. You
2397 should probably change client_lifetime only as a last resort.
2398 If you seem to have many client connections tying up
2399 filedescriptors, we recommend first tuning the read_timeout,
2400 request_timeout, persistent_request_timeout and quick_abort values.
2403 NAME: half_closed_clients
2405 LOC: Config.onoff.half_closed_clients
2408 Some clients may shutdown the sending side of their TCP
2409 connections, while leaving their receiving sides open. Sometimes,
2410 Squid can not tell the difference between a half-closed and a
2411 fully-closed TCP connection. By default, half-closed client
2412 connections are kept open until a read(2) or write(2) on the
2413 socket returns an error. Change this option to 'off' and Squid
2414 will immediately close client connections when read(2) returns
2415 "no more data to read."
2420 LOC: Config.Timeout.pconn
2421 DEFAULT: 120 seconds
2423 Timeout for idle persistent connections to servers and other
2430 LOC: Config.Timeout.ident
2433 Maximum time to wait for IDENT lookups to complete.
2435 If this is too high, and you enabled IDENT lookups from untrusted
2436 users, you might be susceptible to denial-of-service by having
2437 many ident requests going at once.
2441 NAME: shutdown_lifetime
2444 LOC: Config.shutdownLifetime
2447 When SIGTERM or SIGHUP is received, the cache is put into
2448 "shutdown pending" mode until all active sockets are closed.
2449 This value is the lifetime to set for all open descriptors
2450 during shutdown mode. Any active clients after this many
2451 seconds will receive a 'timeout' message.
2456 -----------------------------------------------------------------------------
2464 Defining an Access List
2466 acl aclname acltype string1 ...
2467 acl aclname acltype "file" ...
2469 when using "file", the file should contain one item per line
2471 acltype is one of the types described below
2473 By default, regular expressions are CASE-SENSITIVE. To make
2474 them case-insensitive, use the -i option.
2476 acl aclname src ip-address/netmask ... (clients IP address)
2477 acl aclname src addr1-addr2/netmask ... (range of addresses)
2478 acl aclname dst ip-address/netmask ... (URL host's IP address)
2479 acl aclname myip ip-address/netmask ... (local socket IP address)
2481 acl aclname arp mac-address ... (xx:xx:xx:xx:xx:xx notation)
2482 # The arp ACL requires the special configure option --enable-arp-acl.
2483 # Furthermore, the ARP ACL code is not portable to all operating systems.
2484 # It works on Linux, Solaris, Windows, FreeBSD, and some other *BSD variants.
2486 # NOTE: Squid can only determine the MAC address for clients that are on
2487 # the same subnet. If the client is on a different subnet, then Squid cannot
2488 # find out its MAC address.
2490 acl aclname srcdomain .foo.com ... # reverse lookup, client IP
2491 acl aclname dstdomain .foo.com ... # Destination server from URL
2492 acl aclname srcdom_regex [-i] xxx ... # regex matching client name
2493 acl aclname dstdom_regex [-i] xxx ... # regex matching server
2494 # For dstdomain and dstdom_regex a reverse lookup is tried if a IP
2495 # based URL is used and no match is found. The name "none" is used
2496 # if the reverse lookup fails.
2498 acl aclname time [day-abbrevs] [h1:m1-h2:m2]
2507 h1:m1 must be less than h2:m2
2508 acl aclname url_regex [-i] ^http:// ... # regex matching on whole URL
2509 acl aclname urlpath_regex [-i] \.gif$ ... # regex matching on URL path
2510 acl aclname port 80 70 21 ...
2511 acl aclname port 0-1024 ... # ranges allowed
2512 acl aclname myport 3128 ... # (local socket TCP port)
2513 acl aclname proto HTTP FTP ...
2514 acl aclname method GET POST ...
2515 acl aclname browser [-i] regexp ...
2516 # pattern match on User-Agent header
2517 acl aclname referer_regex [-i] regexp ...
2518 # pattern match on Referer header
2519 # Referer is highly unreliable, so use with care
2520 acl aclname ident username ...
2521 acl aclname ident_regex [-i] pattern ...
2522 # string match on ident output.
2523 # use REQUIRED to accept any non-null ident.
2524 acl aclname src_as number ...
2525 acl aclname dst_as number ...
2526 # Except for access control, AS numbers can be used for
2527 # routing of requests to specific caches. Here's an
2528 # example for routing all requests for AS#1241 and only
2529 # those to mycache.mydomain.net:
2530 # acl asexample dst_as 1241
2531 # cache_peer_access mycache.mydomain.net allow asexample
2532 # cache_peer_access mycache_mydomain.net deny all
2534 acl aclname proxy_auth [-i] username ...
2535 acl aclname proxy_auth_regex [-i] pattern ...
2536 # list of valid usernames
2537 # use REQUIRED to accept any valid username.
2539 # NOTE: when a Proxy-Authentication header is sent but it is not
2540 # needed during ACL checking the username is NOT logged
2543 # NOTE: proxy_auth requires a EXTERNAL authentication program
2544 # to check username/password combinations (see
2545 # auth_param directive).
2547 # NOTE: proxy_auth can't be used in a transparent proxy as
2548 # the browser needs to be configured for using a proxy in order
2549 # to respond to proxy authentication.
2551 acl aclname snmp_community string ...
2552 # A community string to limit access to your SNMP Agent
2555 # acl snmppublic snmp_community public
2557 acl aclname maxconn number
2558 # This will be matched when the client's IP address has
2559 # more than <number> HTTP connections established.
2561 acl aclname max_user_ip [-s] number
2562 # This will be matched when the user attempts to log in from more
2563 # than <number> different ip addresses. The authenticate_ip_ttl
2564 # parameter controls the timeout on the ip entries.
2565 # If -s is specified the limit is strict, denying browsing
2566 # from any further IP addresses until the ttl has expired. Without
2567 # -s Squid will just annoy the user by "randomly" denying requests.
2568 # (the counter is reset each time the limit is reached and a
2569 # request is denied)
2570 # NOTE: in acceleration mode or where there is mesh of child proxies,
2571 # clients may appear to come from multiple addresses if they are
2572 # going through proxy farms, so a limit of 1 may cause user problems.
2574 acl aclname req_mime_type mime-type1 ...
2575 # regex match agains the mime type of the request generated
2576 # by the client. Can be used to detect file upload or some
2577 # types HTTP tunneling requests.
2578 # NOTE: This does NOT match the reply. You cannot use this
2579 # to match the returned file type.
2581 acl aclname rep_mime_type mime-type1 ...
2582 # regex match against the mime type of the reply received by
2583 # squid. Can be used to detect file download or some
2584 # types HTTP tunneling requests.
2585 # NOTE: This has no effect in http_access rules. It only has
2586 # effect in rules that affect the reply data stream such as
2587 # http_reply_access.
2589 acl acl_name external class_name [arguments...]
2590 # external ACL lookup via a helper class defined by the
2591 # external_acl_type directive.
2593 acl aclname user_cert attribute values...
2594 # match against attributes in a user SSL certificate
2595 # attribute is one of DN/C/O/CN/L/ST
2597 acl aclname ca_cert attribute values...
2598 # match against attributes a users issuing CA SSL certificate
2599 # attribute is one of DN/C/O/CN/L/ST
2601 acl aclname ext_user username ...
2602 acl aclname ext_user_regex [-i] pattern ...
2603 # string match on username returned by external acl processing
2604 # use REQUIRED to accept any non-null user name.
2607 acl macaddress arp 09:00:2b:23:45:67
2608 acl myexample dst_as 1241
2609 acl password proxy_auth REQUIRED
2610 acl fileupload req_mime_type -i ^multipart/form-data$
2611 acl javascript rep_mime_type -i ^application/x-javascript$
2614 #Recommended minimum configuration:
2615 acl all src 0.0.0.0/0.0.0.0
2616 acl manager proto cache_object
2617 acl localhost src 127.0.0.1/255.255.255.255
2618 acl to_localhost dst 127.0.0.0/8
2619 acl SSL_ports port 443 563
2620 acl Safe_ports port 80 # http
2621 acl Safe_ports port 21 # ftp
2622 acl Safe_ports port 443 563 # https, snews
2623 acl Safe_ports port 70 # gopher
2624 acl Safe_ports port 210 # wais
2625 acl Safe_ports port 1025-65535 # unregistered ports
2626 acl Safe_ports port 280 # http-mgmt
2627 acl Safe_ports port 488 # gss-http
2628 acl Safe_ports port 591 # filemaker
2629 acl Safe_ports port 777 # multiling http
2630 acl CONNECT method CONNECT
2636 LOC: Config.accessList.http
2638 DEFAULT_IF_NONE: deny all
2640 Allowing or Denying access based on defined access lists
2642 Access to the HTTP port:
2643 http_access allow|deny [!]aclname ...
2645 NOTE on default values:
2647 If there are no "access" lines present, the default is to deny
2650 If none of the "access" lines cause a match, the default is the
2651 opposite of the last line in the list. If the last line was
2652 deny, the default is allow. Conversely, if the last line
2653 is allow, the default will be deny. For these reasons, it is a
2654 good idea to have an "deny all" or "allow all" entry at the end
2655 of your access lists to avoid potential confusion.
2658 #Recommended minimum configuration:
2660 # Only allow cachemgr access from localhost
2661 http_access allow manager localhost
2662 http_access deny manager
2663 # Deny requests to unknown ports
2664 http_access deny !Safe_ports
2665 # Deny CONNECT to other than SSL ports
2666 http_access deny CONNECT !SSL_ports
2668 # We strongly recommend the following be uncommented to protect innocent
2669 # web applications running on the proxy server who think the only
2670 # one who can access services on "localhost" is a local user
2671 #http_access deny to_localhost
2673 # INSERT YOUR OWN RULE(S) HERE TO ALLOW ACCESS FROM YOUR CLIENTS
2675 # Example rule allowing access from your local networks. Adapt
2676 # to list your (internal) IP networks from where browsing should
2678 #acl our_networks src 192.168.1.0/24 192.168.2.0/24
2679 #http_access allow our_networks
2681 # And finally deny all other access to this proxy
2682 http_access deny all
2686 NAME: http_reply_access
2688 LOC: Config.accessList.reply
2690 DEFAULT_IF_NONE: allow all
2692 Allow replies to client requests. This is complementary to http_access.
2694 http_reply_access allow|deny [!] aclname ...
2696 NOTE: if there are no access lines present, the default is to allow
2699 If none of the access lines cause a match the opposite of the
2700 last line will apply. Thus it is good practice to end the rules
2701 with an "allow all" or "deny all" entry.
2704 #Recommended minimum configuration:
2706 # Insert your own rules here.
2709 # and finally allow by default
2710 http_reply_access allow all
2717 LOC: Config.accessList.icp
2719 DEFAULT_IF_NONE: deny all
2721 Allowing or Denying access to the ICP port based on defined
2724 icp_access allow|deny [!]aclname ...
2726 See http_access for details
2729 #Allow ICP queries from everyone
2730 icp_access allow all
2737 LOC: Config.accessList.miss
2740 Use to force your neighbors to use you as a sibling instead of
2741 a parent. For example:
2743 acl localclients src 172.16.0.0/16
2744 miss_access allow localclients
2745 miss_access deny !localclients
2747 This means only your local clients are allowed to fetch
2748 MISSES and all other clients can only fetch HITS.
2750 By default, allow all clients who passed the http_access rules
2751 to fetch MISSES from us.
2755 # miss_access allow all
2760 NAME: cache_peer_access
2765 Similar to 'cache_peer_domain' but provides more flexibility by
2768 cache_peer_access cache-host allow|deny [!]aclname ...
2770 The syntax is identical to 'http_access' and the other lists of
2771 ACL elements. See the comments for 'http_access' below, or
2772 the Squid FAQ (http://www.squid-cache.org/FAQ/FAQ-10.html).
2775 NAME: ident_lookup_access
2779 DEFAULT_IF_NONE: deny all
2780 LOC: Config.accessList.identLookup
2782 A list of ACL elements which, if matched, cause an ident
2783 (RFC 931) lookup to be performed for this request. For
2784 example, you might choose to always perform ident lookups
2785 for your main multi-user Unix boxes, but not for your Macs
2786 and PCs. By default, ident lookups are not performed for
2789 To enable ident lookups for specific client addresses, you
2790 can follow this example:
2792 acl ident_aware_hosts src 198.168.1.0/255.255.255.0
2793 ident_lookup_access allow ident_aware_hosts
2794 ident_lookup_access deny all
2796 Only src type ACL checks are fully supported. A src_domain
2797 ACL might work at times, but it will not always provide
2801 NAME: tcp_outgoing_tos tcp_outgoing_ds tcp_outgoing_dscp
2804 LOC: Config.accessList.outgoing_tos
2806 Allows you to select a TOS/Diffserv value to mark outgoing
2807 connections with, based on the username or source address
2810 tcp_outgoing_tos ds-field [!]aclname ...
2812 Example where normal_service_net uses the TOS value 0x00
2813 and normal_service_net uses 0x20
2815 acl normal_service_net src 10.0.0.0/255.255.255.0
2816 acl good_service_net src 10.0.1.0/255.255.255.0
2817 tcp_outgoing_tos 0x00 normal_service_net 0x00
2818 tcp_outgoing_tos 0x20 good_service_net
2820 TOS/DSCP values really only have local significance - so you should
2821 know what you're specifying. For more, see RFC 2474
2823 The TOS/DSCP byte must be exactly that - a byte, value 0 - 255, or
2824 "default" to use whatever default your host has.
2826 Processing proceeds in the order specified, and stops at first fully
2830 NAME: tcp_outgoing_address
2833 LOC: Config.accessList.outgoing_address
2835 Allows you to map requests to different outgoing IP addresses
2836 based on the username or sourceaddress of the user making
2839 tcp_outgoing_address ipaddr [[!]aclname] ...
2841 Example where requests from 10.0.0.0/24 will be forwarded
2842 with source address 10.1.0.1, 10.0.2.0/24 forwarded with
2843 source address 10.1.0.2 and the rest will be forwarded with
2844 source address 10.1.0.3.
2846 acl normal_service_net src 10.0.0.0/255.255.255.0
2847 acl good_service_net src 10.0.1.0/255.255.255.0
2848 tcp_outgoing_address 10.0.0.1 normal_service_net
2849 tcp_outgoing_address 10.0.0.2 good_service_net
2850 tcp_outgoing_address 10.0.0.3
2852 Processing proceeds in the order specified, and stops at first fully
2856 NAME: reply_header_max_size
2860 LOC: Config.maxReplyHeaderSize
2862 This specifies the maximum size for HTTP headers in a reply.
2863 Reply headers are usually relatively small (about 512 bytes).
2864 Placing a limit on the reply header size will catch certain
2865 bugs (for example with persistent connections) and possibly
2866 buffer-overflow or denial-of-service attacks.
2869 NAME: reply_body_max_size
2870 COMMENT: size [acl acl...]
2873 LOC: Config.ReplyBodySize
2875 This option specifies the maximum size of a reply body. It can be
2876 used to prevent users from downloading very large files, such as
2877 MP3's and movies. When the reply headers are received, the
2878 reply_body_max_size lines are processed, and the first line where
2879 all (if any) listed ACLs are true is used as the maximum body size
2882 This size is checked twice. First when we get the reply headers,
2883 we check the content-length value. If the content length value exists
2884 and is larger than the allowed size, the request is denied and the
2885 user receives an error message that says "the request or reply
2886 is too large." If there is no content-length, and the reply
2887 size exceeds this limit, the client's connection is just closed
2888 and they will receive a partial reply.
2890 WARNING: downstream caches probably can not detect a partial reply
2891 if there is no content-length header, so they will cache
2892 partial responses and give them out as hits. You should NOT
2893 use this option if you have downstream caches.
2895 WARNING: A maximum size smaller than the size of squid's error messages
2896 will cause an infinite loop and crash squid. Ensure that the smallest
2897 non-zero value you use is greater that the maximum header size plus
2898 the size of your largest error page.
2900 If you set this parameter none (the default), there will be
2906 LOC: Config.accessList.log
2908 COMMENT: allow|deny acl acl...
2910 This options allows you to control which requests gets logged
2911 to access.log (see access_log directive). Requests denied for
2912 logging will also not be accounted for in performance counters.
2916 ADMINISTRATIVE PARAMETERS
2917 -----------------------------------------------------------------------------
2923 LOC: Config.adminEmail
2925 Email-address of local cache manager who will receive
2926 mail if the cache dies. The default is "webmaster."
2933 LOC: Config.EmailFrom
2935 From: email-address for mail sent when the cache dies.
2936 The default is to use 'appname@unique_hostname'.
2937 Default appname value is "squid", can be changed into
2938 src/globals.h before building squid.
2945 LOC: Config.EmailProgram
2947 Email program used to send mail if the cache dies.
2948 The default is "mail". The specified program must complain
2949 with the standard Unix mail syntax:
2950 mail_program recipient < mailfile
2951 Optional command line options can be specified.
2955 NAME: cache_effective_user
2958 LOC: Config.effectiveUser
2960 If you start Squid as root, it will change its effective/real
2961 UID/GID to the user specified below. The default is to change
2962 to UID to nobody. If you define cache_effective_user, but not
2963 cache_effective_group, Squid sets the GID to the effective
2964 user's default group ID (taken from the password file) and
2965 supplementary group list from the from groups membership of
2966 cache_effective_user.
2970 NAME: cache_effective_group
2973 LOC: Config.effectiveGroup
2975 If you want Squid to run with a specific GID regardless of
2976 the group memberships of the effective user then set this
2977 to the group (or GID) you want Squid to run as. When set
2978 all other group privileges of the effective user is ignored
2979 and only this GID is effective. If Squid is not started as
2980 root the user starting Squid must be member of the specified
2985 NAME: httpd_suppress_version_string
2989 LOC: Config.onoff.httpd_suppress_version_string
2991 Suppress Squid version string info in HTTP headers and HTML error pages.
2995 NAME: visible_hostname
2997 LOC: Config.visibleHostname
3000 If you want to present a special hostname in error messages, etc,
3001 define this. Otherwise, the return value of gethostname()
3002 will be used. If you have multiple caches in a cluster and
3003 get errors about IP-forwarding you must set them to have individual
3004 names with this setting.
3008 NAME: unique_hostname
3010 LOC: Config.uniqueHostname
3013 If you want to have multiple machines with the same
3014 'visible_hostname' you must give each machine a different
3015 'unique_hostname' so forwarding loops can be detected.
3019 NAME: hostname_aliases
3021 LOC: Config.hostnameAliases
3024 A list of other DNS names your cache has.
3028 OPTIONS FOR THE CACHE REGISTRATION SERVICE
3029 -----------------------------------------------------------------------------
3031 This section contains parameters for the (optional) cache
3032 announcement service. This service is provided to help
3033 cache administrators locate one another in order to join or
3034 create cache hierarchies.
3036 An 'announcement' message is sent (via UDP) to the registration
3037 service by Squid. By default, the announcement message is NOT
3038 SENT unless you enable it with 'announce_period' below.
3040 The announcement message includes your hostname, plus the
3041 following information from this configuration file:
3047 All current information is processed regularly and made
3048 available on the Web at http://www.ircache.net/Cache/Tracker/.
3051 NAME: announce_period
3053 LOC: Config.Announce.period
3056 This is how frequently to send cache announcements. The
3057 default is `0' which disables sending the announcement
3060 To enable announcing your cache, just uncomment the line
3064 #To enable announcing your cache, just uncomment the line below.
3065 #announce_period 1 day
3072 DEFAULT: tracker.ircache.net
3073 LOC: Config.Announce.host
3079 LOC: Config.Announce.file
3085 LOC: Config.Announce.port
3087 announce_host and announce_port set the hostname and port
3088 number where the registration message will be sent.
3090 Hostname will default to 'tracker.ircache.net' and port will
3091 default default to 3131. If the 'filename' argument is given,
3092 the contents of that file will be included in the announce
3096 NAME: httpd_accel_surrogate_id
3099 LOC: Config.Accel.surrogate_id
3102 Surrogates (http://www.esi.org/architecture_spec_1.0.html)
3103 need an identification token to allow control targeting. Because
3104 a farm of surrogates may all perform the same tasks, they may share
3105 an identification token.
3108 NAME: http_accel_surrogate_remote
3113 LOC: Config.onoff.surrogate_is_remote
3115 Remote surrogates (such as those in a CDN) honour Surrogate-Control: no-store-remote.
3116 Set this to on to have squid behave as a remote surrogate.
3121 COMMENT: libxml2|expat|custom
3123 LOC: ESIParser::Type
3126 ESI markup is not strictly XML compatible. The custom ESI parser
3127 will give higher performance, but cannot handle non ASCII character
3133 -----------------------------------------------------------------------------
3138 LOC: Config.dns_testname_list
3140 DEFAULT_IF_NONE: netscape.com internic.net nlanr.net microsoft.com
3142 The DNS tests exit as soon as the first site is successfully looked up
3144 This test can be disabled with the -D command line option.
3148 NAME: logfile_rotate
3151 LOC: Config.Log.rotateNumber
3153 Specifies the number of logfile rotations to make when you
3154 type 'squid -k rotate'. The default is 10, which will rotate
3155 with extensions 0 through 9. Setting logfile_rotate to 0 will
3156 disable the rotation, but the logfiles are still closed and
3157 re-opened. This will enable you to rename the logfiles
3158 yourself just before sending the rotate signal.
3160 Note, the 'squid -k rotate' command normally sends a USR1
3161 signal to the running squid process. In certain situations
3162 (e.g. on Linux with Async I/O), USR1 is used for other
3163 purposes, so -k rotate uses another signal. It is best to get
3164 in the habit of using 'squid -k rotate' instead of 'kill -USR1
3171 LOC: Config.appendDomain
3174 Appends local domain name to hostnames without any dots in
3175 them. append_domain must begin with a period.
3177 Be warned there are now Internet names with no dots in
3178 them using only top-domain names, so setting this may
3179 cause some Internet sites to become unavailable.
3182 append_domain .yourdomain.com
3186 NAME: tcp_recv_bufsize
3190 LOC: Config.tcpRcvBufsz
3192 Size of receive buffer to set for TCP sockets. Probably just
3193 as easy to change your kernel's default. Set to zero to use
3194 the default buffer size.
3199 LOC: Config.errHtmlText
3202 HTML text to include in error messages. Make this a "mailto"
3203 URL to your admin address, or maybe just a link to your
3204 organizations Web page.
3206 To include this in your error messages, you must rewrite
3207 the error template files (found in the "errors" directory).
3208 Wherever you want the 'err_html_text' line to appear,
3209 insert a %L tag in the error template file.
3212 NAME: email_err_data
3215 LOC: Config.onoff.emailErrData
3218 If enabled, information about the occurred error will be
3219 included in the mailto links of the ERR pages (if %W is set)
3220 so that the email body contains the data.
3221 Syntax is <A HREF="mailto:%w%W">%w</A>
3227 LOC: Config.denyInfoList
3230 Usage: deny_info err_page_name acl
3231 or deny_info http://... acl
3232 Example: deny_info ERR_CUSTOM_ACCESS_DENIED bad_guys
3234 This can be used to return a ERR_ page for requests which
3235 do not pass the 'http_access' rules. A single ACL will cause
3236 the http_access check to fail. If a 'deny_info' line exists
3237 for that ACL Squid returns a corresponding error page.
3239 You may use ERR_ pages that come with Squid or create your own pages
3240 and put them into the configured errors/ directory.
3242 Alternatively you can specify an error URL. The browsers will
3243 get redirected (302) to the specified URL. %s in the redirection
3244 URL will be replaced by the requested URL.
3246 Alternatively you can tell Squid to reset the TCP connection
3247 by specifying TCP_RESET.
3254 LOC: Config.onoff.mem_pools
3256 If set, Squid will keep pools of allocated (but unused) memory
3257 available for future use. If memory is a premium on your
3258 system and you believe your malloc library outperforms Squid
3259 routines, disable this.
3262 NAME: memory_pools_limit
3266 LOC: Config.MemPools.limit
3268 Used only with memory_pools on:
3269 memory_pools_limit 50 MB
3271 If set to a non-zero value, Squid will keep at most the specified
3272 limit of allocated (but unused) memory in memory pools. All free()
3273 requests that exceed this limit will be handled by your malloc
3274 library. Squid does not pre-allocate any memory, just safe-keeps
3275 objects that otherwise would be free()d. Thus, it is safe to set
3276 memory_pools_limit to a reasonably high value even if your
3277 configuration will use less memory.
3279 If set to zero, Squid will keep all memory it can. That is, there
3280 will be no limit on the total amount of memory used for safe-keeping.
3282 To disable memory allocation optimization, do not set
3283 memory_pools_limit to 0. Set memory_pools to "off" instead.
3285 An overhead for maintaining memory pools is not taken into account
3286 when the limit is checked. This overhead is close to four bytes per
3287 object kept. However, pools may actually _save_ memory because of
3288 reduced memory thrashing in your malloc library.
3292 IFDEF: HTTP_VIOLATIONS
3296 LOC: Config.onoff.via
3298 If set (default), Squid will include a Via header in requests and
3299 replies as required by RFC2616.
3306 LOC: opt_forwarded_for
3308 If set, Squid will include your system's IP address or name
3309 in the HTTP requests it forwards. By default it looks like
3312 X-Forwarded-For: 192.1.2.3
3314 If you disable this, it will appear as
3316 X-Forwarded-For: unknown
3319 NAME: log_icp_queries
3323 LOC: Config.onoff.log_udp
3325 If set, ICP queries are logged to access.log. You may wish
3326 do disable this if your ICP load is VERY high to speed things
3327 up or to simplify log analysis.
3334 LOC: Config.onoff.icp_hit_stale
3336 If you want to return ICP_HIT for stale cache objects, set this
3337 option to 'on'. If you have sibling relationships with caches
3338 in other administrative domains, this should be 'off'. If you only
3339 have sibling relationships with caches under your control,
3340 it is probably okay to set this to 'on'.
3341 If set to 'on', your siblings should use the option "allow-miss"
3342 on their cache_peer lines for connecting to you.
3346 NAME: minimum_direct_hops
3349 LOC: Config.minDirectHops
3351 If using the ICMP pinging stuff, do direct fetches for sites
3352 which are no more than this many hops away.
3355 NAME: minimum_direct_rtt
3358 LOC: Config.minDirectRtt
3360 If using the ICMP pinging stuff, do direct fetches for sites
3361 which are no more than this many rtt milliseconds away.
3364 NAME: cachemgr_passwd
3365 TYPE: cachemgrpasswd
3367 LOC: Config.passwd_list
3369 Specify passwords for cachemgr operations.
3371 Usage: cachemgr_passwd password action action ...
3373 Some valid actions are (see cache manager menu for a full list):
3412 * Indicates actions which will not be performed without a
3413 valid password, others can be performed if not listed here.
3415 To disable an action, set the password to "disable".
3416 To allow performing an action without a password, set the
3419 Use the keyword "all" to set the same password for all actions.
3422 cachemgr_passwd secret shutdown
3423 cachemgr_passwd lesssssssecret info stats/objects
3424 cachemgr_passwd disable all
3427 NAME: store_avg_object_size
3431 LOC: Config.Store.avgObjectSize
3433 Average object size, used to estimate number of objects your
3434 cache can hold. See doc/Release-Notes-1.1.txt. The default is
3438 NAME: store_objects_per_bucket
3441 LOC: Config.Store.objectsPerBucket
3443 Target number of objects per bucket in the store hash table.
3444 Lowering this value increases the total number of buckets and
3445 also the storage maintenance rate. The default is 20.
3452 LOC: Config.onoff.client_db
3454 If you want to disable collecting per-client statistics,
3455 turn off client_db here.
3462 LOC: Config.Netdb.low
3468 LOC: Config.Netdb.high
3470 The low and high water marks for the ICMP measurement
3471 database. These are counts, not percents. The defaults are
3472 900 and 1000. When the high water mark is reached, database
3473 entries will be deleted until the low mark is reached.
3477 NAME: netdb_ping_period
3479 LOC: Config.Netdb.period
3482 The minimum period for measuring a site. There will be at
3483 least this much delay between successive pings to the same
3484 network. The default is five minutes.
3492 LOC: Config.onoff.query_icmp
3494 If you want to ask your peers to include ICMP data in their ICP
3495 replies, enable this option.
3497 If your peer has configured Squid (during compilation) with
3498 '--enable-icmp' that peer will send ICMP pings to origin server
3499 sites of the URLs it receives. If you enable this option the
3500 ICP replies from that peer will include the ICMP data (if available).
3501 Then, when choosing a parent cache, Squid will choose the parent with
3502 the minimal RTT to the origin server. When this happens, the
3503 hierarchy field of the access.log will be
3504 "CLOSEST_PARENT_MISS". This option is off by default.
3507 NAME: test_reachability
3511 LOC: Config.onoff.test_reachability
3513 When this is 'on', ICP MISS replies will be ICP_MISS_NOFETCH
3514 instead of ICP_MISS if the target host is NOT in the ICMP
3515 database, or has a zero RTT.
3522 LOC: Config.onoff.buffered_logs
3524 cache.log log file is written with stdio functions, and as such
3525 it can be buffered or unbuffered. By default it will be unbuffered.
3526 Buffering it can speed up the writing slightly (though you are
3527 unlikely to need to worry unless you run with tons of debugging
3528 enabled in which case performance will suffer badly anyway..).
3531 NAME: refresh_all_ims
3535 LOC: Config.onoff.refresh_all_ims
3537 When you enable this option, squid will always check
3538 the origin server for an update when a client sends an
3539 If-Modified-Since request. Many browsers use IMS
3540 requests when the user requests a reload, and this
3541 ensures those clients receive the latest version.
3543 By default (off), squid may return a Not Modified response
3544 based on the age of the cached version.
3547 NAME: reload_into_ims
3548 IFDEF: HTTP_VIOLATIONS
3552 LOC: Config.onoff.reload_into_ims
3554 When you enable this option, client no-cache or ``reload''
3555 requests will be changed to If-Modified-Since requests.
3556 Doing this VIOLATES the HTTP standard. Enabling this
3557 feature could make you liable for problems which it
3560 see also refresh_pattern for a more selective approach.
3565 LOC: Config.accessList.AlwaysDirect
3568 Usage: always_direct allow|deny [!]aclname ...
3570 Here you can use ACL elements to specify requests which should
3571 ALWAYS be forwarded directly to origin servers. For example,
3572 to always directly forward requests for local servers use
3575 acl local-servers dstdomain my.domain.net
3576 always_direct allow local-servers
3578 To always forward FTP requests directly, use
3581 always_direct allow FTP
3583 NOTE: There is a similar, but opposite option named
3584 'never_direct'. You need to be aware that "always_direct deny
3585 foo" is NOT the same thing as "never_direct allow foo". You
3586 may need to use a deny rule to exclude a more-specific case of
3587 some other rule. Example:
3589 acl local-external dstdomain external.foo.net
3590 acl local-servers dstdomain .foo.net
3591 always_direct deny local-external
3592 always_direct allow local-servers
3594 This option replaces some v1.1 options such as local_domain
3600 LOC: Config.accessList.NeverDirect
3603 Usage: never_direct allow|deny [!]aclname ...
3605 never_direct is the opposite of always_direct. Please read
3606 the description for always_direct if you have not already.
3608 With 'never_direct' you can use ACL elements to specify
3609 requests which should NEVER be forwarded directly to origin
3610 servers. For example, to force the use of a proxy for all
3611 requests, except those in your local domain use something like:
3613 acl local-servers dstdomain .foo.net
3614 acl all src 0.0.0.0/0.0.0.0
3615 never_direct deny local-servers
3616 never_direct allow all
3618 or if Squid is inside a firewall and there are local intranet
3619 servers inside the firewall use something like:
3621 acl local-intranet dstdomain .foo.net
3622 acl local-external dstdomain external.foo.net
3623 always_direct deny local-external
3624 always_direct allow local-intranet
3625 never_direct allow all
3627 This option replaces some v1.1 options such as inside_firewall
3631 NAME: request_header_access
3632 IFDEF: HTTP_VIOLATIONS
3633 TYPE: http_header_access[]
3634 LOC: Config.request_header_access
3637 Usage: request_header_access header_name allow|deny [!]aclname ...
3639 WARNING: Doing this VIOLATES the HTTP standard. Enabling
3640 this feature could make you liable for problems which it
3643 This option replaces the old 'anonymize_headers' and the
3644 older 'http_anonymizer' option with something that is much
3645 more configurable. This new method creates a list of ACLs
3646 for each header, allowing you very fine-tuned header
3649 This option only applies to request headers, i.e., from the
3650 client to the server.
3652 You can only specify known headers for the header name.
3653 Other headers are reclassified as 'Other'. You can also
3654 refer to all the headers with 'All'.
3656 For example, to achieve the same behavior as the old
3657 'http_anonymizer standard' option, you should use:
3659 request_header_access From deny all
3660 request_header_access Referer deny all
3661 request_header_access Server deny all
3662 request_header_access User-Agent deny all
3663 request_header_access WWW-Authenticate deny all
3664 request_header_access Link deny all
3666 Or, to reproduce the old 'http_anonymizer paranoid' feature
3669 request_header_access Allow allow all
3670 request_header_access Authorization allow all
3671 request_header_access WWW-Authenticate allow all
3672 request_header_access Cache-Control allow all
3673 request_header_access Content-Encoding allow all
3674 request_header_access Content-Length allow all
3675 request_header_access Content-Type allow all
3676 request_header_access Date allow all
3677 request_header_access Expires allow all
3678 request_header_access Host allow all
3679 request_header_access If-Modified-Since allow all
3680 request_header_access Last-Modified allow all
3681 request_header_access Location allow all
3682 request_header_access Pragma allow all
3683 request_header_access Accept allow all
3684 request_header_access Accept-Charset allow all
3685 request_header_access Accept-Encoding allow all
3686 request_header_access Accept-Language allow all
3687 request_header_access Content-Language allow all
3688 request_header_access Mime-Version allow all
3689 request_header_access Retry-After allow all
3690 request_header_access Title allow all
3691 request_header_access Connection allow all
3692 request_header_access Proxy-Connection allow all
3693 request_header_access All deny all
3695 although many of those are HTTP reply headers, and so should be
3696 controlled with the reply_header_access directive.
3698 By default, all headers are allowed (no anonymizing is
3702 NAME: reply_header_access
3703 IFDEF: HTTP_VIOLATIONS
3704 TYPE: http_header_access[]
3705 LOC: Config.reply_header_access
3708 Usage: reply_header_access header_name allow|deny [!]aclname ...
3710 WARNING: Doing this VIOLATES the HTTP standard. Enabling
3711 this feature could make you liable for problems which it
3714 This option only applies to reply headers, i.e., from the
3715 server to the client.
3717 This is the same as request_header_access, but in the other
3720 This option replaces the old 'anonymize_headers' and the
3721 older 'http_anonymizer' option with something that is much
3722 more configurable. This new method creates a list of ACLs
3723 for each header, allowing you very fine-tuned header
3726 You can only specify known headers for the header name.
3727 Other headers are reclassified as 'Other'. You can also
3728 refer to all the headers with 'All'.
3730 For example, to achieve the same behavior as the old
3731 'http_anonymizer standard' option, you should use:
3733 reply_header_access From deny all
3734 reply_header_access Referer deny all
3735 reply_header_access Server deny all
3736 reply_header_access User-Agent deny all
3737 reply_header_access WWW-Authenticate deny all
3738 reply_header_access Link deny all
3740 Or, to reproduce the old 'http_anonymizer paranoid' feature
3743 reply_header_access Allow allow all
3744 reply_header_access Authorization allow all
3745 reply_header_access WWW-Authenticate allow all
3746 reply_header_access Cache-Control allow all
3747 reply_header_access Content-Encoding allow all
3748 reply_header_access Content-Length allow all
3749 reply_header_access Content-Type allow all
3750 reply_header_access Date allow all
3751 reply_header_access Expires allow all
3752 reply_header_access Host allow all
3753 reply_header_access If-Modified-Since allow all
3754 reply_header_access Last-Modified allow all
3755 reply_header_access Location allow all
3756 reply_header_access Pragma allow all
3757 reply_header_access Accept allow all
3758 reply_header_access Accept-Charset allow all
3759 reply_header_access Accept-Encoding allow all
3760 reply_header_access Accept-Language allow all
3761 reply_header_access Content-Language allow all
3762 reply_header_access Mime-Version allow all
3763 reply_header_access Retry-After allow all
3764 reply_header_access Title allow all
3765 reply_header_access Connection allow all
3766 reply_header_access Proxy-Connection allow all
3767 reply_header_access All deny all
3769 although the HTTP request headers won't be usefully controlled
3770 by this directive -- see request_header_access for details.
3772 By default, all headers are allowed (no anonymizing is
3776 NAME: header_replace
3777 IFDEF: HTTP_VIOLATIONS
3778 TYPE: http_header_replace[]
3779 LOC: Config.request_header_access
3782 Usage: header_replace header_name message
3783 Example: header_replace User-Agent Nutscrape/1.0 (CP/M; 8-bit)
3785 This option allows you to change the contents of headers
3786 denied with header_access above, by replacing them with
3787 some fixed string. This replaces the old fake_user_agent
3790 This only applies to request headers, not reply headers.
3792 By default, headers are removed if denied.
3795 NAME: icon_directory
3797 LOC: Config.icons.directory
3798 DEFAULT: @DEFAULT_ICON_DIR@
3800 Where the icons are stored. These are normally kept in
3804 NAME: global_internal_static
3806 LOC: Config.onoff.global_internal_static
3809 This directive controls is Squid should intercept all requests for
3810 /squid-internal-static/ no matter which host the URL is requesting
3811 (default on setting), or if nothing special should be done for
3812 such URLs (off setting). The purpose of this directive is to make
3813 icons etc work better in complex cache hierarchies where it may
3814 not always be possible for all corners in the cache mesh to reach
3815 the server generating a directory listing.
3818 NAME: short_icon_urls
3820 LOC: Config.icons.use_short_names
3823 If this is enabled Squid will use short URLs for icons.
3824 If disabled it will revert to the old behavior of including
3825 it's own name and port in the URL.
3827 If you run a complex cache hierarchy with a mix of Squid and
3828 other proxies you may need to disable this directive.
3831 NAME: error_directory
3833 LOC: Config.errorDirectory
3834 DEFAULT: @DEFAULT_ERROR_DIR@
3836 If you wish to create your own versions of the default
3837 (English) error files, either to customize them to suit your
3838 language or company copy the template English files to another
3839 directory and point this tag at them.
3842 NAME: maximum_single_addr_tries
3844 LOC: Config.retry.maxtries
3847 This sets the maximum number of connection attempts for a
3848 host that only has one address (for multiple-address hosts,
3849 each address is tried once).
3851 The default value is one attempt, the (not recommended)
3852 maximum is 255 tries. A warning message will be generated
3853 if it is set to a value greater than ten.
3855 Note: This is in addition to the request re-forwarding which
3856 takes place if Squid fails to get a satisfying response.
3859 NAME: retry_on_error
3861 LOC: Config.retry.onerror
3864 If set to on Squid will automatically retry requests when
3865 receiving an error response. This is mainly useful if you
3866 are in a complex cache hierarchy to work around access
3872 LOC: Config.Port.snmp
3876 Squid can now serve statistics and status information via SNMP.
3877 By default it listens to port 3401 on the machine. If you don't
3878 wish to use SNMP, set this to "0".
3880 Note: If you want Squid to use parents for all requests see
3881 the never_direct directive. prefer_direct only modifies how Squid
3882 acts on cachable requests.
3887 LOC: Config.accessList.snmp
3889 DEFAULT_IF_NONE: deny all
3892 Allowing or denying access to the SNMP port.
3894 All access to the agent is denied by default.
3897 snmp_access allow|deny [!]aclname ...
3900 snmp_access allow snmppublic localhost
3901 snmp_access deny all
3904 NAME: snmp_incoming_address
3906 LOC: Config.Addrs.snmp_incoming
3910 NAME: snmp_outgoing_address
3912 LOC: Config.Addrs.snmp_outgoing
3913 DEFAULT: 255.255.255.255
3916 Just like 'udp_incoming_address' above, but for the SNMP port.
3918 snmp_incoming_address is used for the SNMP socket receiving
3919 messages from SNMP agents.
3920 snmp_outgoing_address is used for SNMP packets returned to SNMP
3923 The default snmp_incoming_address (0.0.0.0) is to listen on all
3924 available network interfaces.
3926 If snmp_outgoing_address is set to 255.255.255.255 (the default)
3927 it will use the same socket as snmp_incoming_address. Only
3928 change this if you want to have SNMP replies sent using another
3929 address than where this Squid listens for SNMP queries.
3931 NOTE, snmp_incoming_address and snmp_outgoing_address can not have
3932 the same value since they both use port 3401.
3935 NAME: as_whois_server
3937 LOC: Config.as_whois_server
3938 DEFAULT: whois.ra.net
3939 DEFAULT_IF_NONE: whois.ra.net
3941 WHOIS server to query for AS numbers. NOTE: AS numbers are
3942 queried only when Squid starts up, not for every request.
3947 LOC: Config.Wccp.router
3951 Use this option to define your WCCP ``home'' router for
3952 Squid. Setting the 'wccp_router' to 0.0.0.0 (the default)
3958 LOC: Config.Wccp.version
3962 According to some users, Cisco IOS 11.2 only supports WCCP
3963 version 3. If you're using that version of IOS, change
3967 NAME: wccp_incoming_address
3969 LOC: Config.Wccp.incoming
3973 NAME: wccp_outgoing_address
3975 LOC: Config.Wccp.outgoing
3976 DEFAULT: 255.255.255.255
3979 wccp_incoming_address Use this option if you require WCCP
3980 messages to be received on only one
3981 interface. Do NOT use this option if
3982 you're unsure how many interfaces you
3983 have, or if you know you have only one
3986 wccp_outgoing_address Use this option if you require WCCP
3987 messages to be sent out on only one
3988 interface. Do NOT use this option if
3989 you're unsure how many interfaces you
3990 have, or if you know you have only one
3993 The default behavior is to not bind to any specific address.
3995 NOTE, wccp_incoming_address and wccp_outgoing_address can not have
3996 the same value since they both use port 2048.
4001 DELAY POOL PARAMETERS (all require DELAY_POOLS compilation option)
4002 -----------------------------------------------------------------------------
4006 TYPE: delay_pool_count
4011 This represents the number of delay pools to be used. For example,
4012 if you have one class 2 delay pool and one class 3 delays pool, you
4013 have a total of 2 delay pools.
4017 TYPE: delay_pool_class
4022 This defines the class of each delay pool. There must be exactly one
4023 delay_class line for each delay pool. For example, to define two
4024 delay pools, one of class 2 and one of class 3, the settings above
4028 delay_pools 4 # 4 delay pools
4029 delay_class 1 2 # pool 1 is a class 2 pool
4030 delay_class 2 3 # pool 2 is a class 3 pool
4031 delay_class 3 4 # pool 3 is a class 4 pool
4032 delay_class 4 5 # pool 4 is a class 5 pool
4034 The delay pool classes are:
4036 class 1 Everything is limited by a single aggregate
4039 class 2 Everything is limited by a single aggregate
4040 bucket as well as an "individual" bucket chosen
4041 from bits 25 through 32 of the IP address.
4043 class 3 Everything is limited by a single aggregate
4044 bucket as well as a "network" bucket chosen
4045 from bits 17 through 24 of the IP address and a
4046 "individual" bucket chosen from bits 17 through
4047 32 of the IP address.
4049 class 4 Everything in a class 3 delay pool, with an
4050 additional limit on a per user basis. This
4051 only takes effect if the username is established
4052 in advance - by forcing authentication in your
4055 class 5 Requests are grouped according their tag (see
4056 external_acl's tag= reply).
4058 NOTE: If an IP address is a.b.c.d
4059 -> bits 25 through 32 are "d"
4060 -> bits 17 through 24 are "c"
4061 -> bits 17 through 32 are "c * 256 + d"
4065 TYPE: delay_pool_access
4070 This is used to determine which delay pool a request falls into.
4072 delay_access is sorted per pool and the matching starts with pool 1,
4073 then pool 2, ..., and finally pool N. The first delay pool where the
4074 request is allowed is selected for the request. If it does not allow
4075 the request to any pool then the request is not delayed (default).
4077 For example, if you want some_big_clients in delay
4078 pool 1 and lotsa_little_clients in delay pool 2:
4081 delay_access 1 allow some_big_clients
4082 delay_access 1 deny all
4083 delay_access 2 allow lotsa_little_clients
4084 delay_access 2 deny all
4085 delay_access 3 allow authenticated_clients
4088 NAME: delay_parameters
4089 TYPE: delay_pool_rates
4094 This defines the parameters for a delay pool. Each delay pool has
4095 a number of "buckets" associated with it, as explained in the
4096 description of delay_class. For a class 1 delay pool, the syntax is:
4098 delay_parameters pool aggregate
4100 For a class 2 delay pool:
4102 delay_parameters pool aggregate individual
4104 For a class 3 delay pool:
4106 delay_parameters pool aggregate network individual
4108 For a class 4 delay pool:
4110 delay_parameters pool aggregate network individual user
4112 For a class 5 delay pool:
4114 delay_parameters pool tag
4116 The variables here are:
4118 pool a pool number - ie, a number between 1 and the
4119 number specified in delay_pools as used in
4122 aggregate the "delay parameters" for the aggregate bucket
4125 individual the "delay parameters" for the individual
4126 buckets (class 2, 3).
4128 network the "delay parameters" for the network buckets
4131 user the delay parameters for the user buckets
4134 tag the delay parameters for the tag buckets
4137 A pair of delay parameters is written restore/maximum, where restore is
4138 the number of bytes (not bits - modem and network speeds are usually
4139 quoted in bits) per second placed into the bucket, and maximum is the
4140 maximum number of bytes which can be in the bucket at any time.
4142 For example, if delay pool number 1 is a class 2 delay pool as in the
4143 above example, and is being used to strictly limit each host to 64kbps
4144 (plus overheads), with no overall limit, the line is:
4146 delay_parameters 1 -1/-1 8000/8000
4148 Note that the figure -1 is used to represent "unlimited".
4150 And, if delay pool number 2 is a class 3 delay pool as in the above
4151 example, and you want to limit it to a total of 256kbps (strict limit)
4152 with each 8-bit network permitted 64kbps (strict limit) and each
4153 individual host permitted 4800bps with a bucket maximum size of 64kb
4154 to permit a decent web page to be downloaded at a decent speed
4155 (if the network is not being limited due to overuse) but slow down
4156 large downloads more significantly:
4158 delay_parameters 2 32000/32000 8000/8000 600/8000
4160 There must be one delay_parameters line for each delay pool.
4162 Finally, for a class 4 delay pool as in the example - each user will
4163 be limited to 128Kb no matter how many workstations they are logged into.:
4165 delay_parameters 4 32000/32000 8000/8000 600/64000 16000/16000
4168 NAME: delay_initial_bucket_level
4169 COMMENT: (percent, 0-100)
4173 LOC: Config.Delay.initial
4175 The initial bucket percentage is used to determine how much is put
4176 in each bucket when squid starts, is reconfigured, or first notices
4177 a host accessing it (in class 2 and class 3, individual hosts and
4178 networks only have buckets associated with them once they have been
4182 NAME: incoming_icp_average
4185 LOC: Config.comm_incoming.icp_average
4188 NAME: incoming_http_average
4191 LOC: Config.comm_incoming.http_average
4194 NAME: incoming_dns_average
4197 LOC: Config.comm_incoming.dns_average
4200 NAME: min_icp_poll_cnt
4203 LOC: Config.comm_incoming.icp_min_poll
4206 NAME: min_dns_poll_cnt
4209 LOC: Config.comm_incoming.dns_min_poll
4212 NAME: min_http_poll_cnt
4215 LOC: Config.comm_incoming.http_min_poll
4217 Heavy voodoo here. I can't even believe you are reading this.
4218 Are you crazy? Don't even think about adjusting these unless
4219 you understand the algorithms in comm_select.c first!
4222 NAME: max_open_disk_fds
4224 LOC: Config.max_open_disk_fds
4227 To avoid having disk as the I/O bottleneck Squid can optionally
4228 bypass the on-disk cache if more than this amount of disk file
4229 descriptors are open.
4231 A value of 0 indicates no limit.
4236 LOC: Config.onoff.offline
4239 Enable this option and Squid will never try to validate cached
4243 NAME: uri_whitespace
4244 TYPE: uri_whitespace
4245 LOC: Config.uri_whitespace
4248 What to do with requests that have whitespace characters in the
4251 strip: The whitespace characters are stripped out of the URL.
4252 This is the behavior recommended by RFC2396.
4253 deny: The request is denied. The user receives an "Invalid
4255 allow: The request is allowed and the URI is not changed. The
4256 whitespace characters remain in the URI. Note the
4257 whitespace is passed to redirector processes if they
4259 encode: The request is allowed and the whitespace characters are
4260 encoded according to RFC1738. This could be considered
4261 a violation of the HTTP/1.1
4262 RFC because proxies are not allowed to rewrite URI's.
4263 chop: The request is allowed and the URI is chopped at the
4264 first whitespace. This might also be considered a
4271 LOC: Config.accessList.brokenPosts
4273 A list of ACL elements which, if matched, causes Squid to send
4274 an extra CRLF pair after the body of a PUT/POST request.
4276 Some HTTP servers has broken implementations of PUT/POST,
4277 and rely on an extra CRLF pair sent by some WWW clients.
4279 Quote from RFC 2068 section 4.1 on this matter:
4281 Note: certain buggy HTTP/1.0 client implementations generate an
4282 extra CRLF's after a POST request. To restate what is explicitly
4283 forbidden by the BNF, an HTTP/1.1 client must not preface or follow
4284 a request with an extra CRLF.
4287 acl buggy_server url_regex ^http://....
4288 broken_posts allow buggy_server
4291 NAME: mcast_miss_addr
4292 IFDEF: MULTICAST_MISS_STREAM
4294 LOC: Config.mcast_miss.addr
4295 DEFAULT: 255.255.255.255
4297 If you enable this option, every "cache miss" URL will
4298 be sent out on the specified multicast address.
4300 Do not enable this option unless you are are absolutely
4301 certain you understand what you are doing.
4304 NAME: mcast_miss_ttl
4305 IFDEF: MULTICAST_MISS_STREAM
4307 LOC: Config.mcast_miss.ttl
4310 This is the time-to-live value for packets multicasted
4311 when multicasting off cache miss URLs is enabled. By
4312 default this is set to 'site scope', i.e. 16.
4315 NAME: mcast_miss_port
4316 IFDEF: MULTICAST_MISS_STREAM
4318 LOC: Config.mcast_miss.port
4321 This is the port number to be used in conjunction with
4325 NAME: mcast_miss_encode_key
4326 IFDEF: MULTICAST_MISS_STREAM
4328 LOC: Config.mcast_miss.encode_key
4329 DEFAULT: XXXXXXXXXXXXXXXX
4331 The URLs that are sent in the multicast miss stream are
4332 encrypted. This is the encryption key.
4335 NAME: nonhierarchical_direct
4337 LOC: Config.onoff.nonhierarchical_direct
4340 By default, Squid will send any non-hierarchical requests
4341 (matching hierarchy_stoplist or not cachable request type) direct
4344 If you set this to off, Squid will prefer to send these
4345 requests to parents.
4347 Note that in most configurations, by turning this off you will only
4348 add latency to these request without any improvement in global hit
4351 If you are inside an firewall see never_direct instead of
4357 LOC: Config.onoff.prefer_direct
4360 Normally Squid tries to use parents for most requests. If you for some
4361 reason like it to first try going direct and only use a parent if
4362 going direct fails set this to on.
4364 By combining nonhierarchical_direct off and prefer_direct on you
4365 can set up Squid to use a parent as a backup path if going direct
4369 NAME: strip_query_terms
4371 LOC: Config.onoff.strip_query_terms
4374 By default, Squid strips query terms from requested URLs before
4375 logging. This protects your user's privacy.
4380 LOC: Config.coredump_dir
4382 DEFAULT_IF_NONE: none
4384 By default Squid leaves core files in the directory from where
4385 it was started. If you set 'coredump_dir' to a directory
4386 that exists, Squid will chdir() to that directory at startup
4387 and coredump files will be left there.
4390 # Leave coredumps in the first cache dir
4391 coredump_dir @DEFAULT_SWAP_DIR@
4395 NAME: redirector_bypass
4397 LOC: Config.onoff.redirector_bypass
4400 When this is 'on', a request will not go through the
4401 redirector if all redirectors are busy. If this is 'off'
4402 and the redirector queue grows too large, Squid will exit
4403 with a FATAL error and ask you to increase the number of
4404 redirectors. You should only enable this if the redirectors
4405 are not critical to your caching system. If you use
4406 redirectors for access control, and you enable this option,
4407 users may have access to pages they should not
4408 be allowed to request.
4411 NAME: ignore_unknown_nameservers
4413 LOC: Config.onoff.ignore_unknown_nameservers
4416 By default Squid checks that DNS responses are received
4417 from the same IP addresses they are sent to. If they
4418 don't match, Squid ignores the response and writes a warning
4419 message to cache.log. You can allow responses from unknown
4420 nameservers by setting this option to 'off'.
4423 NAME: digest_generation
4424 IFDEF: USE_CACHE_DIGESTS
4426 LOC: Config.onoff.digest_generation
4429 This controls whether the server will generate a Cache Digest
4430 of its contents. By default, Cache Digest generation is
4431 enabled if Squid is compiled with USE_CACHE_DIGESTS defined.
4434 NAME: digest_bits_per_entry
4435 IFDEF: USE_CACHE_DIGESTS
4437 LOC: Config.digest.bits_per_entry
4440 This is the number of bits of the server's Cache Digest which
4441 will be associated with the Digest entry for a given HTTP
4442 Method and URL (public key) combination. The default is 5.
4445 NAME: digest_rebuild_period
4446 IFDEF: USE_CACHE_DIGESTS
4449 LOC: Config.digest.rebuild_period
4452 This is the number of seconds between Cache Digest rebuilds.
4455 NAME: digest_rewrite_period
4457 IFDEF: USE_CACHE_DIGESTS
4459 LOC: Config.digest.rewrite_period
4462 This is the number of seconds between Cache Digest writes to
4466 NAME: digest_swapout_chunk_size
4469 IFDEF: USE_CACHE_DIGESTS
4470 LOC: Config.digest.swapout_chunk_size
4473 This is the number of bytes of the Cache Digest to write to
4474 disk at a time. It defaults to 4096 bytes (4KB), the Squid
4478 NAME: digest_rebuild_chunk_percentage
4479 COMMENT: (percent, 0-100)
4480 IFDEF: USE_CACHE_DIGESTS
4482 LOC: Config.digest.rebuild_chunk_percentage
4485 This is the percentage of the Cache Digest to be scanned at a
4486 time. By default it is set to 10% of the Cache Digest.
4491 LOC: Config.chroot_dir
4494 Use this to have Squid do a chroot() while initializing. This
4495 also causes Squid to fully drop root privileges after
4496 initializing. This means, for example, if you use a HTTP
4497 port less than 1024 and try to reconfigure, you will get an
4501 NAME: client_persistent_connections
4503 LOC: Config.onoff.client_pconns
4507 NAME: server_persistent_connections
4509 LOC: Config.onoff.server_pconns
4512 Persistent connection support for clients and servers. By
4513 default, Squid uses persistent connections (when allowed)
4514 with its clients and servers. You can use these options to
4515 disable persistent connections with clients and/or servers.
4518 NAME: balance_on_multiple_ip
4520 LOC: Config.onoff.balance_on_multiple_ip
4523 Some load balancing servers based on round robin DNS have been
4524 found not to preserve user session state across requests
4525 to different IP addresses.
4527 By default Squid rotates IP's per request. By disabling
4528 this directive only connection failure triggers rotation.
4531 NAME: detect_broken_pconn
4533 LOC: Config.onoff.detect_broken_server_pconns
4536 Some servers have been found to incorrectly signal the use
4537 of HTTP/1.0 persistent connections even on replies not
4538 compatible, causing significant delays. This server problem
4539 has mostly been seen on redirects.
4541 By enabling this directive Squid attempts to detect such
4542 broken replies and automatically assume the reply is finished
4543 after 10 seconds timeout.
4546 NAME: pipeline_prefetch
4548 LOC: Config.onoff.pipeline_prefetch
4551 To boost the performance of pipelined requests to closer
4552 match that of a non-proxied environment Squid can try to fetch
4553 up to two requests in parallel from a pipeline.
4555 Defaults to off for bandwidth management and access logging
4559 NAME: extension_methods
4561 LOC: Config.ext_methods
4564 Squid only knows about standardized HTTP request methods.
4565 You can add up to 20 additional "extension" methods here.
4568 NAME: request_entities
4570 LOC: Config.onoff.request_entities
4573 Squid defaults to deny GET and HEAD requests with request entities,
4574 as the meaning of such requests are undefined in the HTTP standard
4575 even if not explicitly forbidden.
4577 Set this directive to on if you have clients which insists
4578 on sending request entities in GET or HEAD requests.
4581 NAME: high_response_time_warning
4584 LOC: Config.warnings.high_rptm
4587 If the one-minute median response time exceeds this value,
4588 Squid prints a WARNING with debug level 0 to get the
4589 administrators attention. The value is in milliseconds.
4592 NAME: high_page_fault_warning
4594 LOC: Config.warnings.high_pf
4597 If the one-minute average page fault rate exceeds this
4598 value, Squid prints a WARNING with debug level 0 to get
4599 the administrators attention. The value is in page faults
4603 NAME: high_memory_warning
4605 LOC: Config.warnings.high_memory
4608 If the memory usage (as determined by mallinfo) exceeds
4609 value, Squid prints a WARNING with debug level 0 to get
4610 the administrators attention.
4613 NAME: store_dir_select_algorithm
4615 LOC: Config.store_dir_select_algorithm
4618 Set this to 'round-robin' as an alternative.
4625 LOC: Config.Log.forward
4627 Logs the server-side requests.
4629 This is currently work in progress.
4635 LOC: Config.onoff.ie_refresh
4638 Microsoft Internet Explorer up until version 5.5 Service
4639 Pack 1 has an issue with transparent proxies, wherein it
4640 is impossible to force a refresh. Turning this on provides
4641 a partial fix to the problem, by causing all IMS-REFRESH
4642 requests from older IE versions to check the origin server
4643 for fresh content. This reduces hit ratio by some amount
4644 (~10% in my experience), but allows users to actually get
4645 fresh content when they want it. Note because Squid
4646 cannot tell if the user is using 5.5 or 5.5SP1, the behavior
4647 of 5.5 is unchanged from old versions of Squid (i.e. a
4648 forced refresh is impossible). Newer versions of IE will,
4649 hopefully, continue to have the new behavior and will be
4650 handled based on that assumption. This option defaults to
4651 the old Squid behavior, which is better for hit ratios but
4652 worse for clients using IE, if they need to be able to
4653 force fresh content.
4656 NAME: vary_ignore_expire
4659 LOC: Config.onoff.vary_ignore_expire
4662 Many HTTP servers supporting Vary gives such objects
4663 immediate expiry time with no cache-control header
4664 when requested by a HTTP/1.0 client. This option
4665 enables Squid to ignore such expiry times until
4666 HTTP/1.1 is fully implemented.
4667 WARNING: This may eventually cause some varying
4668 objects not intended for caching to get cached.
4671 NAME: sleep_after_fork
4672 COMMENT: (microseconds)
4674 LOC: Config.sleep_after_fork
4677 When this is set to a non-zero value, the main Squid process
4678 sleeps the specified number of microseconds after a fork()
4679 system call. This sleep may help the situation where your
4680 system reports fork() failures due to lack of (virtual)
4681 memory. Note, however, if you have a lot of child
4682 processes, these sleep delays will add up and your
4683 Squid will not service requests for some amount of time
4684 until all the child processes have been started.
4687 NAME: minimum_expiry_time
4690 LOC: Config.minimum_expiry_time
4693 The minimum caching time according to (Expires - Date)
4694 Headers Squid honors if the object can't be revalidated
4695 defaults to 60 seconds. In reverse proxy enorinments it
4696 might be desirable to honor shorter object lifetimes. It
4697 is most likely better to make your server return a
4698 meaningful Last-Modified header however. In ESI environments
4699 where page fragments often have short lifetimes, this will
4700 often be best set to 0.
4703 NAME: relaxed_header_parser
4704 COMMENT: on|off|warn
4706 LOC: Config.onoff.relaxed_header_parser
4709 In the default "on" setting Squid accepts certain forms
4710 of non-compliant HTTP messages where it is unambiguous
4711 what the sending application intended even if the message
4712 is not correctly formatted. The messages is then normalized
4713 to the correct form when forwarded by Squid.
4715 If set to "warn" then a warning will be emitted in cache.log
4716 each time such HTTP error is encountered.
4718 If set to "off" then such HTTP errors will cause the request
4719 or response to be rejected.