# WELCOME TO SQUID 2.7.STABLE9 # ---------------------------- # # This is the default Squid configuration file. You may wish # to look at the Squid home page (http://www.squid-cache.org/) # for the FAQ and other documentation. # # The default Squid config file shows what the defaults for # various options happen to be. If you don't need to change the # default, you shouldn't uncomment the line. Doing so may cause # run-time problems. In some cases "none" refers to no default # setting at all, while in other cases it refers to a valid # option - the comments for that keyword indicate if this is the # case. # # Configuration options can be included using the "include" directive. # Include takes a list of files to include. Quoting and wildcards is # supported. # # For example, # # include /path/to/included/file/squid.acl.config # # Includes can be nested up to a hard-coded depth of 16 levels. # This arbitrary restriction is to prevent recursive include references # from causing Squid entering an infinite loop whilst trying to load # configuration files. # OPTIONS FOR AUTHENTICATION # ----------------------------------------------------------------------------- # TAG: auth_param # This is used to define parameters for the various authentication # schemes supported by Squid. # # format: auth_param scheme parameter [setting] # # The order in which authentication schemes are presented to the client is # dependent on the order the scheme first appears in config file. IE # has a bug (it's not RFC 2617 compliant) in that it will use the basic # scheme if basic is the first entry presented, even if more secure # schemes are presented. For now use the order in the recommended # settings section below. If other browsers have difficulties (don't # recognize the schemes offered even if you are using basic) either # put basic first, or disable the other schemes (by commenting out their # program entry). # # Once an authentication scheme is fully configured, it can only be # shutdown by shutting squid down and restarting. Changes can be made on # the fly and activated with a reconfigure. I.E. You can change to a # different helper, but not unconfigure the helper completely. # # Please note that while this directive defines how Squid processes # authentication it does not automatically activate authentication. # To use authentication you must in addition make use of ACLs based # on login name in http_access (proxy_auth, proxy_auth_regex or # external with %LOGIN used in the format tag). The browser will be # challenged for authentication on the first such acl encountered # in http_access processing and will also be re-challenged for new # login credentials if the request is being denied by a proxy_auth # type acl. # # WARNING: authentication can't be used in a transparently intercepting # proxy as the client then thinks it is talking to an origin server and # not the proxy. This is a limitation of bending the TCP/IP protocol to # transparently intercepting port 80, not a limitation in Squid. # # === Parameters for the basic scheme follow. === # # "program" cmdline # Specify the command for the external authenticator. Such a program # reads a line containing "username password" and replies "OK" or # "ERR" in an endless loop. "ERR" responses may optionally be followed # by a error description available as %m in the returned error page. # # By default, the basic authentication scheme is not used unless a # program is specified. # # If you want to use the traditional proxy authentication, jump over to # the helpers/basic_auth/NCSA directory and type: # % make # % make install # # Then, set this line to something like # # auth_param basic program /usr/lib/squid/ncsa_auth /usr/etc/passwd # # "children" numberofchildren # The number of authenticator processes to spawn. If you start too few # squid will have to wait for them to process a backlog of credential # verifications, slowing it down. When credential verifications are # done via a (slow) network you are likely to need lots of # authenticator processes. # auth_param basic children 5 # # "concurrency" numberofconcurrentrequests # The number of concurrent requests/channels the helper supports. # Changes the protocol used to include a channel number first on # the request/response line, allowing multiple requests to be sent # to the same helper in parallell without wating for the response. # Must not be set unless it's known the helper supports this. # # "realm" realmstring # Specifies the realm name which is to be reported to the client for # the basic proxy authentication scheme (part of the text the user # will see when prompted their username and password). # auth_param basic realm Squid proxy-caching web server # # "credentialsttl" timetolive # Specifies how long squid assumes an externally validated # username:password pair is valid for - in other words how often the # helper program is called for that user. Set this low to force # revalidation with short lived passwords. Note that setting this high # does not impact your susceptibility to replay attacks unless you are # using an one-time password system (such as SecureID). If you are using # such a system, you will be vulnerable to replay attacks unless you # also use the max_user_ip ACL in an http_access rule. # auth_param basic credentialsttl 2 hours # # "casesensitive" on|off # Specifies if usernames are case sensitive. Most user databases are # case insensitive allowing the same username to be spelled using both # lower and upper case letters, but some are case sensitive. This # makes a big difference for user_max_ip ACL processing and similar. # auth_param basic casesensitive off # # "blankpassword" on|off # Specifies if blank passwords should be supported. Defaults to off # as there is multiple authentication backends which handles blank # passwords as "guest" access. # # === Parameters for the digest scheme follow === # # "program" cmdline # Specify the command for the external authenticator. Such a program # reads a line containing "username":"realm" and replies with the # appropriate H(A1) value hex encoded or ERR if the user (or his H(A1) # hash) does not exists. See RFC 2616 for the definition of H(A1). # "ERR" responses may optionally be followed by a error description # available as %m in the returned error page. # # By default, the digest authentication scheme is not used unless a # program is specified. # # If you want to use a digest authenticator, jump over to the # helpers/digest_auth/ directory and choose the authenticator to use. # It it's directory type # % make # % make install # # Then, set this line to something like # # auth_param digest program /usr/lib/squid/digest_auth_pw /usr/etc/digpass # # "children" numberofchildren # The number of authenticator processes to spawn. If you start too few # squid will have to wait for them to process a backlog of credential # verifications, slowing it down. When credential verifications are # done via a (slow) network you are likely to need lots of # authenticator processes. # auth_param digest children 5 # # "concurrency" numberofconcurrentrequests # The number of concurrent requests/channels the helper supports. # Changes the protocol used to include a channel number first on # the request/response line, allowing multiple requests to be sent # to the same helper in parallell without wating for the response. # Must not be set unless it's known the helper supports this. # # "realm" realmstring # Specifies the realm name which is to be reported to the client for the # digest proxy authentication scheme (part of the text the user will see # when prompted their username and password). # auth_param digest realm Squid proxy-caching web server # # "nonce_garbage_interval" timeinterval # Specifies the interval that nonces that have been issued to clients are # checked for validity. # auth_param digest nonce_garbage_interval 5 minutes # # "nonce_max_duration" timeinterval # Specifies the maximum length of time a given nonce will be valid for. # auth_param digest nonce_max_duration 30 minutes # # "nonce_max_count" number # Specifies the maximum number of times a given nonce can be used. # auth_param digest nonce_max_count 50 # # "nonce_strictness" on|off # Determines if squid requires strict increment-by-1 behavior for nonce # counts, or just incrementing (off - for use when useragents generate # nonce counts that occasionally miss 1 (ie, 1,2,4,6)). # auth_param digest nonce_strictness off # # "check_nonce_count" on|off # This directive if set to off can disable the nonce count check # completely to work around buggy digest qop implementations in certain # mainstream browser versions. Default on to check the nonce count to # protect from authentication replay attacks. # auth_param digest check_nonce_count on # # "post_workaround" on|off # This is a workaround to certain buggy browsers who sends an incorrect # request digest in POST requests when reusing the same nonce as acquired # earlier in response to a GET request. # auth_param digest post_workaround off # # === NTLM scheme options follow === # # "program" cmdline # Specify the command for the external NTLM authenticator. Such a # program participates in the NTLMSSP exchanges between Squid and the # client and reads commands according to the Squid NTLMSSP helper # protocol. See helpers/ntlm_auth/ for details. Recommended ntlm # authenticator is ntlm_auth from Samba-3.X, but a number of other # ntlm authenticators is available. # # By default, the ntlm authentication scheme is not used unless a # program is specified. # # auth_param ntlm program /usr/bin/ntlm_auth --helper-protocol=squid-2.5-ntlmssp # # "children" numberofchildren # The number of authenticator processes to spawn. If you start too few # squid will have to wait for them to process a backlog of credential # verifications, slowing it down. When credential verifications are # done via a (slow) network you are likely to need lots of # authenticator processes. # auth_param ntlm children 5 # # "keep_alive" on|off # This option enables the use of keep-alive on the initial # authentication request. It has been reported some versions of MSIE # have problems if this is enabled, but performance will be increased # if enabled. # # auth_param ntlm keep_alive on # # === Negotiate scheme options follow === # # "program" cmdline # Specify the command for the external Negotiate authenticator. Such a # program participates in the SPNEGO exchanges between Squid and the # client and reads commands according to the Squid ntlmssp helper # protocol. See helpers/ntlm_auth/ for details. Recommended SPNEGO # authenticator is ntlm_auth from Samba-4.X. # # By default, the Negotiate authentication scheme is not used unless a # program is specified. # # auth_param negotiate program /path/to/samba/bin/ntlm_auth --helper-protocol=gss-spnego # # "children" numberofchildren # The number of authenticator processes to spawn. If you start too few # squid will have to wait for them to process a backlog of credential # verifications, slowing it down. When credential verifications are # done via a (slow) network you are likely to need lots of # authenticator processes. # auth_param negotiate children 5 # # "keep_alive" on|off # If you experience problems with PUT/POST requests when using the # Negotiate authentication scheme then you can try setting this to # off. This will cause Squid to forcibly close the connection on # the initial requests where the browser asks which schemes are # supported by the proxy. # # auth_param negotiate keep_alive on # #Recommended minimum configuration per scheme: #auth_param negotiate program #auth_param negotiate children 5 #auth_param negotiate keep_alive on #auth_param ntlm program #auth_param ntlm children 5 #auth_param ntlm keep_alive on #auth_param digest program #auth_param digest children 5 #auth_param digest realm Squid proxy-caching web server #auth_param digest nonce_garbage_interval 5 minutes #auth_param digest nonce_max_duration 30 minutes #auth_param digest nonce_max_count 50 #auth_param basic program #auth_param basic children 5 #auth_param basic realm Squid proxy-caching web server #auth_param basic credentialsttl 2 hours #auth_param basic casesensitive off # TAG: authenticate_cache_garbage_interval # The time period between garbage collection across the username cache. # This is a tradeoff between memory utilization (long intervals - say # 2 days) and CPU (short intervals - say 1 minute). Only change if you # have good reason to. # #Default: # authenticate_cache_garbage_interval 1 hour # TAG: authenticate_ttl # The time a user & their credentials stay in the logged in user cache # since their last request. When the garbage interval passes, all user # credentials that have passed their TTL are removed from memory. # #Default: # authenticate_ttl 1 hour # TAG: authenticate_ip_ttl # If you use proxy authentication and the 'max_user_ip' ACL, this # directive controls how long Squid remembers the IP addresses # associated with each user. Use a small value (e.g., 60 seconds) if # your users might change addresses quickly, as is the case with # dialups. You might be safe using a larger value (e.g., 2 hours) in a # corporate LAN environment with relatively static address assignments. # #Default: # authenticate_ip_ttl 0 seconds # TAG: authenticate_ip_shortcircuit_ttl # Cache authentication credentials per client IP address for this # long. Default is 0 seconds (disabled). # # See also authenticate_ip_shortcircuit_access directive. # #Default: # authenticate_ip_shortcircuit_ttl 0 seconds # ACCESS CONTROLS # ----------------------------------------------------------------------------- # TAG: external_acl_type # This option defines external acl classes using a helper program to # look up the status # # external_acl_type name [options] FORMAT.. /path/to/helper [helper arguments..] # # Options: # # ttl=n TTL in seconds for cached results (defaults to 3600 # for 1 hour) # negative_ttl=n # TTL for cached negative lookups (default same # as ttl) # children=n number of processes spawn to service external acl # lookups of this type. (default 5). # concurrency=n concurrency level per process. Only used with helpers # capable of processing more than one query at a time. # Note: see compatibility note below # cache=n result cache size, 0 is unbounded (default) # grace= Percentage remaining of TTL where a refresh of a # cached entry should be initiated without needing to # wait for a new reply. (default 0 for no grace period) # protocol=2.5 Compatibility mode for Squid-2.5 external acl helpers # # FORMAT specifications # # %LOGIN Authenticated user login name # %EXT_USER Username from external acl # %IDENT Ident user name # %SRC Client IP # %SRCPORT Client source port # %URI Requested URI # %DST Requested host # %PROTO Requested protocol # %PORT Requested port # %METHOD Request method # %MYADDR Squid interface address # %MYPORT Squid http_port number # %PATH Requested URL-path (including query-string if any) # %USER_CERT SSL User certificate in PEM format # %USER_CERTCHAIN SSL User certificate chain in PEM format # %USER_CERT_xx SSL User certificate subject attribute xx # %USER_CA_xx SSL User certificate issuer attribute xx # %{Header} HTTP request header "Header" # %{Hdr:member} HTTP request header "Hdr" list member "member" # %{Hdr:;member} # HTTP request header list member using ; as # list separator. ; can be any non-alphanumeric # character. # %ACL The ACL name # %DATA The ACL arguments. If not used then any arguments # is automatically added at the end # # In addition to the above, any string specified in the referencing # acl will also be included in the helper request line, after the # specified formats (see the "acl external" directive) # # The helper receives lines per the above format specification, # and returns lines starting with OK or ERR indicating the validity # of the request and optionally followed by additional keywords with # more details. # # General result syntax: # # OK/ERR keyword=value ... # # Defined keywords: # # user= The users name (login also understood) # password= The users password (for PROXYPASS login= cache_peer) # message= Error message or similar used as %o in error messages # (error also understood) # log= String to be logged in access.log. Available as # %ea in logformat specifications # # If protocol=3.0 (the default) then URL escaping is used to protect # each value in both requests and responses. # # If using protocol=2.5 then all values need to be enclosed in quotes # if they may contain whitespace, or the whitespace escaped using \. # And quotes or \ characters within the keyword value must be \ escaped. # # When using the concurrency= option the protocol is changed by # introducing a query channel tag infront of the request/response. # The query channel tag is a number between 0 and concurrency-1. # # Compatibility Note: The children= option was named concurrency= in # Squid-2.5.STABLE3 and earlier, and was accepted as an alias for the # duration of the Squid-2.5 releases to keep compatibility. However, # the meaning of concurrency= option has changed in Squid-2.6 to match # that of Squid-3 and the old syntax no longer works. # #Default: # none # TAG: acl # Defining an Access List # # Every access list definition must begin with an aclname and acltype, # followed by either type-specific arguments or a quoted filename that # they are read from. # # acl aclname acltype argument ... # acl aclname acltype "file" ... # # when using "file", the file should contain one item per line. # # By default, regular expressions are CASE-SENSITIVE. To make # them case-insensitive, use the -i option. # # acl aclname src ip-address/netmask ... (clients IP address) # acl aclname src addr1-addr2/netmask ... (range of addresses) # acl aclname dst ip-address/netmask ... (URL host's IP address) # acl aclname myip ip-address/netmask ... (local socket IP address) # # acl aclname arp mac-address ... (xx:xx:xx:xx:xx:xx notation) # # The arp ACL requires the special configure option --enable-arp-acl. # # Furthermore, the arp ACL code is not portable to all operating systems. # # It works on Linux, Solaris, FreeBSD and some other *BSD variants. # # # # NOTE: Squid can only determine the MAC address for clients that are on # # the same subnet. If the client is on a different subnet, then Squid cannot # # find out its MAC address. # # acl aclname srcdomain .foo.com ... # reverse lookup, client IP # acl aclname dstdomain .foo.com ... # Destination server from URL # acl aclname srcdom_regex [-i] xxx ... # regex matching client name # acl aclname dstdom_regex [-i] xxx ... # regex matching server # # For dstdomain and dstdom_regex a reverse lookup is tried if a IP # # based URL is used and no match is found. The name "none" is used # # if the reverse lookup fails. # # acl aclname time [day-abbrevs] [h1:m1-h2:m2] # # day-abbrevs: # # S - Sunday # # M - Monday # # T - Tuesday # # W - Wednesday # # H - Thursday # # F - Friday # # A - Saturday # # h1:m1 must be less than h2:m2 # acl aclname url_regex [-i] ^http:// ... # regex matching on whole URL # acl aclname urlpath_regex [-i] \.gif$ ... # regex matching on URL path # acl aclname urllogin [-i] [^a-zA-Z0-9] ... # regex matching on URL login field # acl aclname port 80 70 21 ... # acl aclname port 0-1024 ... # ranges allowed # acl aclname myport 3128 ... # (local socket TCP port) # acl aclname myportname 3128 ... # http(s)_port name # acl aclname proto HTTP FTP ... # acl aclname method GET POST ... # acl aclname browser [-i] regexp ... # # pattern match on User-Agent header (see also req_header below) # acl aclname referer_regex [-i] regexp ... # # pattern match on Referer header # # Referer is highly unreliable, so use with care # acl aclname ident username ... # acl aclname ident_regex [-i] pattern ... # # string match on ident output. # # use REQUIRED to accept any non-null ident. # acl aclname src_as number ... # acl aclname dst_as number ... # # Except for access control, AS numbers can be used for # # routing of requests to specific caches. Here's an # # example for routing all requests for AS#1241 and only # # those to mycache.mydomain.net: # # acl asexample dst_as 1241 # # cache_peer_access mycache.mydomain.net allow asexample # # cache_peer_access mycache_mydomain.net deny all # # acl aclname proxy_auth [-i] username ... # acl aclname proxy_auth_regex [-i] pattern ... # # list of valid usernames # # use REQUIRED to accept any valid username. # # # # NOTE: when a Proxy-Authentication header is sent but it is not # # needed during ACL checking the username is NOT logged # # in access.log. # # # # NOTE: proxy_auth requires a EXTERNAL authentication program # # to check username/password combinations (see # # auth_param directive). # # # # NOTE: proxy_auth can't be used in a transparent proxy as # # the browser needs to be configured for using a proxy in order # # to respond to proxy authentication. # # acl aclname snmp_community string ... # # A community string to limit access to your SNMP Agent # # Example: # # # # acl snmppublic snmp_community public # # acl aclname maxconn number # # This will be matched when the client's IP address has # # more than HTTP connections established. # # acl aclname max_user_ip [-s] number # # This will be matched when the user attempts to log in from more # # than different ip addresses. The authenticate_ip_ttl # # parameter controls the timeout on the ip entries. # # If -s is specified the limit is strict, denying browsing # # from any further IP addresses until the ttl has expired. Without # # -s Squid will just annoy the user by "randomly" denying requests. # # (the counter is reset each time the limit is reached and a # # request is denied) # # NOTE: in acceleration mode or where there is mesh of child proxies, # # clients may appear to come from multiple addresses if they are # # going through proxy farms, so a limit of 1 may cause user problems. # # acl aclname req_mime_type mime-type ... # # regex match against the mime type of the request generated # # by the client. Can be used to detect file upload or some # # types HTTP tunneling requests. # # NOTE: This does NOT match the reply. You cannot use this # # to match the returned file type. # # acl aclname req_header header-name [-i] any\.regex\.here # # regex match against any of the known request headers. May be # # thought of as a superset of "browser", "referer" and "mime-type" # # ACLs. # # acl aclname rep_mime_type mime-type ... # # regex match against the mime type of the reply received by # # squid. Can be used to detect file download or some # # types HTTP tunneling requests. # # NOTE: This has no effect in http_access rules. It only has # # effect in rules that affect the reply data stream such as # # http_reply_access. # # acl aclname rep_header header-name [-i] any\.regex\.here # # regex match against any of the known reply headers. May be # # thought of as a superset of "browser", "referer" and "mime-type" # # ACLs. # # # # Example: # # # # acl many_spaces rep_header Content-Disposition -i [[:space:]]{3,} # # acl aclname external class_name [arguments...] # # external ACL lookup via a helper class defined by the # # external_acl_type directive. # # acl aclname urlgroup group1 ... # # match against the urlgroup as indicated by redirectors # # acl aclname user_cert attribute values... # # match against attributes in a user SSL certificate # # attribute is one of DN/C/O/CN/L/ST # # acl aclname ca_cert attribute values... # # match against attributes a users issuing CA SSL certificate # # attribute is one of DN/C/O/CN/L/ST # # acl aclname ext_user username ... # acl aclname ext_user_regex [-i] pattern ... # # string match on username returned by external acl helper # # use REQUIRED to accept any non-null user name. # #Examples: #acl macaddress arp 09:00:2b:23:45:67 #acl myexample dst_as 1241 #acl password proxy_auth REQUIRED #acl fileupload req_mime_type -i ^multipart/form-data$ #acl javascript rep_mime_type -i ^application/x-javascript$ # #Recommended minimum configuration: acl all src all acl manager proto cache_object acl localhost src 127.0.0.1/32 acl to_localhost dst 127.0.0.0/8 0.0.0.0/32 # # Example rule allowing access from your local networks. # Adapt to list your (internal) IP networks from where browsing # should be allowed acl localnet src 10.0.0.0/8 # RFC1918 possible internal network acl localnet src 172.16.0.0/12 # RFC1918 possible internal network acl localnet src 192.168.0.0/16 # RFC1918 possible internal network # acl SSL_ports port 443 # https acl SSL_ports port 563 # snews acl SSL_ports port 873 # rsync acl Safe_ports port 80 # http acl Safe_ports port 21 # ftp acl Safe_ports port 443 # https acl Safe_ports port 70 # gopher acl Safe_ports port 210 # wais acl Safe_ports port 1025-65535 # unregistered ports acl Safe_ports port 280 # http-mgmt acl Safe_ports port 488 # gss-http acl Safe_ports port 591 # filemaker acl Safe_ports port 777 # multiling http acl Safe_ports port 631 # cups acl Safe_ports port 873 # rsync acl Safe_ports port 901 # SWAT acl purge method PURGE acl CONNECT method CONNECT # TAG: http_access # Allowing or Denying access based on defined access lists # # Access to the HTTP port: # http_access allow|deny [!]aclname ... # # NOTE on default values: # # If there are no "access" lines present, the default is to deny # the request. # # If none of the "access" lines cause a match, the default is the # opposite of the last line in the list. If the last line was # deny, the default is allow. Conversely, if the last line # is allow, the default will be deny. For these reasons, it is a # good idea to have an "deny all" or "allow all" entry at the end # of your access lists to avoid potential confusion. # #Default: # http_access deny all # #Recommended minimum configuration: # # Only allow cachemgr access from localhost http_access allow manager localhost http_access deny manager # Only allow purge requests from localhost http_access allow purge localhost http_access deny purge # Deny requests to unknown ports http_access deny !Safe_ports # Deny CONNECT to other than SSL ports http_access deny CONNECT !SSL_ports # # We strongly recommend the following be uncommented to protect innocent # web applications running on the proxy server who think the only # one who can access services on "localhost" is a local user #http_access deny to_localhost # # INSERT YOUR OWN RULE(S) HERE TO ALLOW ACCESS FROM YOUR CLIENTS # Example rule allowing access from your local networks. # Adapt localnet in the ACL section to list your (internal) IP networks # from where browsing should be allowed #http_access allow localnet http_access allow localhost # And finally deny all other access to this proxy http_access deny all # TAG: http_access2 # Allowing or Denying access based on defined access lists # # Identical to http_access, but runs after redirectors. If not set # then only http_access is used. # #Default: # none # TAG: http_reply_access # Allow replies to client requests. This is complementary to http_access. # # http_reply_access allow|deny [!] aclname ... # # NOTE: if there are no access lines present, the default is to allow # all replies # # If none of the access lines cause a match the opposite of the # last line will apply. Thus it is good practice to end the rules # with an "allow all" or "deny all" entry. # #Default: # http_reply_access allow all # TAG: icp_access # Allowing or Denying access to the ICP port based on defined # access lists # # icp_access allow|deny [!]aclname ... # # See http_access for details # #Default: # icp_access deny all # #Allow ICP queries from local networks only icp_access allow localnet icp_access deny all # TAG: htcp_access # Allowing or Denying access to the HTCP port based on defined # access lists # # htcp_access allow|deny [!]aclname ... # # See http_access for details # # NOTE: The default if no htcp_access lines are present is to # deny all traffic. This default may cause problems with peers # using the htcp or htcp-oldsquid options. # #Default: # htcp_access deny all # #Allow HTCP queries from local networks only # htcp_access allow localnet # htcp_access deny all # TAG: htcp_clr_access # Allowing or Denying access to purge content using HTCP based # on defined access lists # # htcp_clr_access allow|deny [!]aclname ... # # See http_access for details # ##Allow HTCP CLR requests from trusted peers #acl htcp_clr_peer src 172.16.1.2 #htcp_clr_access allow htcp_clr_peer # #Default: # htcp_clr_access deny all # TAG: miss_access # Use to force your neighbors to use you as a sibling instead of # a parent. For example: # # acl localclients src 172.16.0.0/16 # miss_access allow localclients # miss_access deny !localclients # # This means only your local clients are allowed to fetch # MISSES and all other clients can only fetch HITS. # # By default, allow all clients who passed the http_access rules # to fetch MISSES from us. # #Default setting: # miss_access allow all # TAG: ident_lookup_access # A list of ACL elements which, if matched, cause an ident # (RFC931) lookup to be performed for this request. For # example, you might choose to always perform ident lookups # for your main multi-user Unix boxes, but not for your Macs # and PCs. By default, ident lookups are not performed for # any requests. # # To enable ident lookups for specific client addresses, you # can follow this example: # # acl ident_aware_hosts src 198.168.1.0/255.255.255.0 # ident_lookup_access allow ident_aware_hosts # ident_lookup_access deny all # # Only src type ACL checks are fully supported. A src_domain # ACL might work at times, but it will not always provide # the correct result. # #Default: # ident_lookup_access deny all # TAG: reply_body_max_size bytes deny acl acl... # This option specifies the maximum size of a reply body in bytes. # It can be used to prevent users from downloading very large files, # such as MP3's and movies. When the reply headers are received, # the reply_body_max_size lines are processed, and the first line with # a result of "deny" is used as the maximum body size for this reply. # This size is checked twice. First when we get the reply headers, # we check the content-length value. If the content length value exists # and is larger than the allowed size, the request is denied and the # user receives an error message that says "the request or reply # is too large." If there is no content-length, and the reply # size exceeds this limit, the client's connection is just closed # and they will receive a partial reply. # # WARNING: downstream caches probably can not detect a partial reply # if there is no content-length header, so they will cache # partial responses and give them out as hits. You should NOT # use this option if you have downstream caches. # # If you set this parameter to zero (the default), there will be # no limit imposed. # #Default: # reply_body_max_size 0 allow all # TAG: authenticate_ip_shortcircuit_access # Access list determining when shortcicuiting the authentication process # based on source IP cached credentials is acceptable. Use this to deny # using the ip auth cache on requests from child proxies or other source # ip's having multiple users. # # See also authenticate_ip_shortcircuit_ttl directive # #Default: # none # OPTIONS FOR X-Forwarded-For # ----------------------------------------------------------------------------- # TAG: follow_x_forwarded_for # Allowing or Denying the X-Forwarded-For header to be followed to # find the original source of a request. # # Requests may pass through a chain of several other proxies # before reaching us. The X-Forwarded-For header will contain a # comma-separated list of the IP addresses in the chain, with the # rightmost address being the most recent. # # If a request reaches us from a source that is allowed by this # configuration item, then we consult the X-Forwarded-For header # to see where that host received the request from. If the # X-Forwarded-For header contains multiple addresses, and if # acl_uses_indirect_client is on, then we continue backtracking # until we reach an address for which we are not allowed to # follow the X-Forwarded-For header, or until we reach the first # address in the list. (If acl_uses_indirect_client is off, then # it's impossible to backtrack through more than one level of # X-Forwarded-For addresses.) # # The end result of this process is an IP address that we will # refer to as the indirect client address. This address may # be treated as the client address for access control, delay # pools and logging, depending on the acl_uses_indirect_client, # delay_pool_uses_indirect_client and log_uses_indirect_client # options. # # SECURITY CONSIDERATIONS: # # Any host for which we follow the X-Forwarded-For header # can place incorrect information in the header, and Squid # will use the incorrect information as if it were the # source address of the request. This may enable remote # hosts to bypass any access control restrictions that are # based on the client's source addresses. # # For example: # # acl localhost src 127.0.0.1 # acl my_other_proxy srcdomain .proxy.example.com # follow_x_forwarded_for allow localhost # follow_x_forwarded_for allow my_other_proxy # #Default: # follow_x_forwarded_for deny all # TAG: acl_uses_indirect_client on|off # Controls whether the indirect client address # (see follow_x_forwarded_for) is used instead of the # direct client address in acl matching. # #Default: # acl_uses_indirect_client on # TAG: delay_pool_uses_indirect_client on|off # Controls whether the indirect client address # (see follow_x_forwarded_for) is used instead of the # direct client address in delay pools. # #Default: # delay_pool_uses_indirect_client on # TAG: log_uses_indirect_client on|off # Controls whether the indirect client address # (see follow_x_forwarded_for) is used instead of the # direct client address in the access log. # #Default: # log_uses_indirect_client on # SSL OPTIONS # ----------------------------------------------------------------------------- # TAG: ssl_unclean_shutdown # Note: This option is only available if Squid is rebuilt with the # --enable-ssl option # # Some browsers (especially MSIE) bugs out on SSL shutdown # messages. # #Default: # ssl_unclean_shutdown off # TAG: ssl_engine # Note: This option is only available if Squid is rebuilt with the # --enable-ssl option # # The OpenSSL engine to use. You will need to set this if you # would like to use hardware SSL acceleration for example. # #Default: # none # TAG: sslproxy_client_certificate # Note: This option is only available if Squid is rebuilt with the # --enable-ssl option # # Client SSL Certificate to use when proxying https:// URLs # #Default: # none # TAG: sslproxy_client_key # Note: This option is only available if Squid is rebuilt with the # --enable-ssl option # # Client SSL Key to use when proxying https:// URLs # #Default: # none # TAG: sslproxy_version # Note: This option is only available if Squid is rebuilt with the # --enable-ssl option # # SSL version level to use when proxying https:// URLs # #Default: # sslproxy_version 1 # TAG: sslproxy_options # Note: This option is only available if Squid is rebuilt with the # --enable-ssl option # # SSL engine options to use when proxying https:// URLs # #Default: # none # TAG: sslproxy_cipher # Note: This option is only available if Squid is rebuilt with the # --enable-ssl option # # SSL cipher list to use when proxying https:// URLs # #Default: # none # TAG: sslproxy_cafile # Note: This option is only available if Squid is rebuilt with the # --enable-ssl option # # file containing CA certificates to use when verifying server # certificates while proxying https:// URLs # #Default: # none # TAG: sslproxy_capath # Note: This option is only available if Squid is rebuilt with the # --enable-ssl option # # directory containing CA certificates to use when verifying # server certificates while proxying https:// URLs # #Default: # none # TAG: sslproxy_flags # Note: This option is only available if Squid is rebuilt with the # --enable-ssl option # # Various flags modifying the use of SSL while proxying https:// URLs: # DONT_VERIFY_PEER Accept certificates even if they fail to # verify. # NO_DEFAULT_CA Don't use the default CA list built in # to OpenSSL. # #Default: # none # TAG: sslpassword_program # Note: This option is only available if Squid is rebuilt with the # --enable-ssl option # # Specify a program used for entering SSL key passphrases # when using encrypted SSL certificate keys. If not specified # keys must either be unencrypted, or Squid started with the -N # option to allow it to query interactively for the passphrase. # #Default: # none # NETWORK OPTIONS # ----------------------------------------------------------------------------- # TAG: http_port # Usage: port [options] # hostname:port [options] # 1.2.3.4:port [options] # # The socket addresses where Squid will listen for HTTP client # requests. You may specify multiple socket addresses. # There are three forms: port alone, hostname with port, and # IP address with port. If you specify a hostname or IP # address, Squid binds the socket to that specific # address. This replaces the old 'tcp_incoming_address' # option. Most likely, you do not need to bind to a specific # address, so you can use the port number alone. # # If you are running Squid in accelerator mode, you # probably want to listen on port 80 also, or instead. # # The -I command line option will override the *first* port # specified here. # # You may specify multiple socket addresses on multiple lines. # # Options: # # transparent Support for transparent interception of # outgoing requests without browser settings. # # tproxy Support Linux TPROXY for spoofing outgoing # connections using the client IP address. # # accel Accelerator mode. See also the related vhost, # vport and defaultsite directives. # # defaultsite=domainname # What to use for the Host: header if it is not present # in a request. Determines what site (not origin server) # accelerators should consider the default. # Defaults to visible_hostname:port if not set # May be combined with vport=NN to override the port number. # Implies accel. # # vhost Accelerator mode using Host header for virtual # domain support. Implies accel. # # vport Accelerator with IP based virtual host support. # Implies accel. # # vport=NN As above, but uses specified port number rather # than the http_port number. Implies accel. # # allow-direct Allow direct forwarding in accelerator mode. Normally # accelerated requests is denied direct forwarding as it # never_direct was used. # # urlgroup= Default urlgroup to mark requests with (see # also acl urlgroup and url_rewrite_program) # # protocol= Protocol to reconstruct accelerated requests with. # Defaults to http. # # no-connection-auth # Prevent forwarding of Microsoft connection oriented # authentication (NTLM, Negotiate and Kerberos) # # act-as-origin # Act is if this Squid is the origin server. # This currently means generate own Date: and # Expires: headers. Implies accel. # # http11 Enables HTTP/1.1 support to clients. The HTTP/1.1 # support is still incomplete with an internal HTTP/1.0 # hop, but should work with most clients. The main # HTTP/1.1 features missing due to this is forwarding # of requests using chunked transfer encoding (results # in 411) and forwarding of 1xx responses (silently # dropped) # # name= Specifies a internal name for the port. Defaults to # the port specification (port or addr:port) # # tcpkeepalive[=idle,interval,timeout] # Enable TCP keepalive probes of idle connections # idle is the initial time before TCP starts probing # the connection, interval how often to probe, and # timeout the time before giving up. # # If you run Squid on a dual-homed machine with an internal # and an external interface we recommend you to specify the # internal address:port in http_port. This way Squid will only be # visible on the internal address. # # Squid normally listens to port 3128 http_port 3128 # TAG: https_port # Note: This option is only available if Squid is rebuilt with the # --enable-ssl option # # Usage: [ip:]port cert=certificate.pem [key=key.pem] [options...] # # The socket address where Squid will listen for HTTPS client # requests. # # This is really only useful for situations where you are running # squid in accelerator mode and you want to do the SSL work at the # accelerator level. # # You may specify multiple socket addresses on multiple lines, # each with their own SSL certificate and/or options. # # Options: # # In addition to the options specified for http_port the folling # SSL related options is supported: # # cert= Path to SSL certificate (PEM format). # # key= Path to SSL private key file (PEM format) # if not specified, the certificate file is # assumed to be a combined certificate and # key file. # # version= The version of SSL/TLS supported # 1 automatic (default) # 2 SSLv2 only # 3 SSLv3 only # 4 TLSv1 only # # cipher= Colon separated list of supported ciphers. # # options= Various SSL engine options. The most important # being: # NO_SSLv2 Disallow the use of SSLv2 # NO_SSLv3 Disallow the use of SSLv3 # NO_TLSv1 Disallow the use of TLSv1 # SINGLE_DH_USE Always create a new key when using # temporary/ephemeral DH key exchanges # See src/ssl_support.c or OpenSSL SSL_CTX_set_options # documentation for a complete list of options. # # clientca= File containing the list of CAs to use when # requesting a client certificate. # # cafile= File containing additional CA certificates to # use when verifying client certificates. If unset # clientca will be used. # # capath= Directory containing additional CA certificates # and CRL lists to use when verifying client certificates. # # crlfile= File of additional CRL lists to use when verifying # the client certificate, in addition to CRLs stored in # the capath. Implies VERIFY_CRL flag below. # # dhparams= File containing DH parameters for temporary/ephemeral # DH key exchanges. # # sslflags= Various flags modifying the use of SSL: # DELAYED_AUTH # Don't request client certificates # immediately, but wait until acl processing # requires a certificate (not yet implemented). # NO_DEFAULT_CA # Don't use the default CA lists built in # to OpenSSL. # NO_SESSION_REUSE # Don't allow for session reuse. Each connection # will result in a new SSL session. # VERIFY_CRL # Verify CRL lists when accepting client # certificates. # VERIFY_CRL_ALL # Verify CRL lists for all certificates in the # client certificate chain. # # sslcontext= SSL session ID context identifier. # # #Default: # none # TAG: tcp_outgoing_tos # Allows you to select a TOS/Diffserv value to mark outgoing # connections with, based on the username or source address # making the request. # # tcp_outgoing_tos ds-field [!]aclname ... # # Example where normal_service_net uses the TOS value 0x00 # and good_service_net uses 0x20 # # acl normal_service_net src 10.0.0.0/255.255.255.0 # acl good_service_net src 10.0.1.0/255.255.255.0 # tcp_outgoing_tos 0x00 normal_service_net # tcp_outgoing_tos 0x20 good_service_net # # TOS/DSCP values really only have local significance - so you should # know what you're specifying. For more information, see RFC2474 and # RFC3260. # # The TOS/DSCP byte must be exactly that - a octet value 0 - 255, or # "default" to use whatever default your host has. Note that in # practice often only values 0 - 63 is usable as the two highest bits # have been redefined for use by ECN (RFC3168). # # Processing proceeds in the order specified, and stops at first fully # matching line. # # Note: The use of this directive using client dependent ACLs is # incompatible with the use of server side persistent connections. To # ensure correct results it is best to set server_persisten_connections # to off when using this directive in such configurations. # #Default: # none # TAG: tcp_outgoing_address # Allows you to map requests to different outgoing IP addresses # based on the username or source address of the user making # the request. # # tcp_outgoing_address ipaddr [[!]aclname] ... # # Example where requests from 10.0.0.0/24 will be forwarded # with source address 10.1.0.1, 10.0.2.0/24 forwarded with # source address 10.1.0.2 and the rest will be forwarded with # source address 10.1.0.3. # # acl normal_service_net src 10.0.0.0/24 # acl good_service_net src 10.0.1.0/24 10.0.2.0/24 # tcp_outgoing_address 10.1.0.1 normal_service_net # tcp_outgoing_address 10.1.0.2 good_service_net # tcp_outgoing_address 10.1.0.3 # # Processing proceeds in the order specified, and stops at first fully # matching line. # # Note: The use of this directive using client dependent ACLs is # incompatible with the use of server side persistent connections. To # ensure correct results it is best to set server_persistent_connections # to off when using this directive in such configurations. # #Default: # none # TAG: zph_mode # This option enables packet level marking of HIT/MISS responses, # either using IP TOS or socket priority. # off Feature disabled # tos Set the IP TOS/Diffserv field # priority Set the socket priority (may get mapped to TOS by OS, # otherwise only usable in local rulesets) # option Embed the mark in an IP option field. See also # zph_option. # # See also tcp_outgoing_tos for details/requirements about TOS usage. # #Default: # zph_mode off # TAG: zph_local # Allows you to select a TOS/Diffserv/Priority value to mark local hits. # Default: 0 (disabled). # #Default: # zph_local 0 # TAG: zph_sibling # Allows you to select a TOS/Diffserv/Priority value to mark sibling hits. # Default: 0 (disabled). # #Default: # zph_sibling 0 # TAG: zph_parent # Allows you to select a TOS/Diffserv/Priority value to mark parent hits. # Default: 0 (disabled). # #Default: # zph_parent 0 # TAG: zph_option # The IP option to use when zph_mode is set to "option". Defaults to # 136 which is officially registered as "SATNET Stream ID". # #Default: # zph_option 136 # OPTIONS WHICH AFFECT THE NEIGHBOR SELECTION ALGORITHM # ----------------------------------------------------------------------------- # TAG: cache_peer # To specify other caches in a hierarchy, use the format: # # cache_peer hostname type http-port icp-port [options] # # For example, # # # proxy icp # # hostname type port port options # # -------------------- -------- ----- ----- ----------- # cache_peer parent.foo.net parent 3128 3130 proxy-only default # cache_peer sib1.foo.net sibling 3128 3130 proxy-only # cache_peer sib2.foo.net sibling 3128 3130 proxy-only # # type: either 'parent', 'sibling', or 'multicast'. # # proxy-port: The port number where the cache listens for proxy # requests. # # icp-port: Used for querying neighbor caches about # objects. To have a non-ICP neighbor # specify '7' for the ICP port and make sure the # neighbor machine has the UDP echo port # enabled in its /etc/inetd.conf file. # NOTE: Also requires icp_port option enabled to send/receive # requests via this method. # # options: proxy-only # weight=n # ttl=n # no-query # default # round-robin # carp # multicast-responder # multicast-siblings # closest-only # no-digest # no-netdb-exchange # no-delay # login=user:password | PASS | *:password # connect-timeout=nn # digest-url=url # allow-miss # max-conn=n # htcp # htcp-oldsquid # originserver # userhash # sourcehash # name=xxx # monitorurl=url # monitorsize=sizespec # monitorinterval=seconds # monitortimeout=seconds # forceddomain=name # ssl # sslcert=/path/to/ssl/certificate # sslkey=/path/to/ssl/key # sslversion=1|2|3|4 # sslcipher=... # ssloptions=... # front-end-https[=on|auto] # connection-auth[=on|off|auto] # idle=n # http11 # # use 'proxy-only' to specify objects fetched # from this cache should not be saved locally. # # use 'weight=n' to affect the selection of a peer # during any weighted peer-selection mechanisms. # The weight must be an integer; default is 1, # larger weights are favored more. # This option does not affect parent selection if a peering # protocol is not in use. # # use 'ttl=n' to specify a IP multicast TTL to use # when sending an ICP queries to this address. # Only useful when sending to a multicast group. # Because we don't accept ICP replies from random # hosts, you must configure other group members as # peers with the 'multicast-responder' option below. # # use 'no-query' to NOT send ICP queries to this # neighbor. # # use 'default' if this is a parent cache which can # be used as a "last-resort" if a peer cannot be located # by any of the peer-selection mechanisms. # If specified more than once, only the first is used. # # use 'round-robin' to define a set of parents which # should be used in a round-robin fashion in the # absence of any ICP queries. # # use 'carp' to define a set of parents which should # be used as a CARP array. The requests will be # distributed among the parents based on the CARP load # balancing hash function based on their weight. # # 'multicast-responder' indicates the named peer # is a member of a multicast group. ICP queries will # not be sent directly to the peer, but ICP replies # will be accepted from it. # # the 'multicast-siblings' option is meant to be used # only for cache peers of type "multicast". It instructs # Squid that ALL members of this multicast group have # "sibling" relationship with it, not "parent". This is # an optimization that avoids useless multicast queries # to a multicast group when the requested object would # be fetched only from a "parent" cache, anyway. It's # useful, e.g., when configuring a pool of redundant # Squid proxies, being members of the same # multicast group. # # 'closest-only' indicates that, for ICP_OP_MISS # replies, we'll only forward CLOSEST_PARENT_MISSes # and never FIRST_PARENT_MISSes. # # use 'no-digest' to NOT request cache digests from # this neighbor. # # 'no-netdb-exchange' disables requesting ICMP # RTT database (NetDB) from the neighbor. # # use 'no-delay' to prevent access to this neighbor # from influencing the delay pools. # # use 'login=user:password' if this is a personal/workgroup # proxy and your parent requires proxy authentication. # Note: The string can include URL escapes (i.e. %20 for # spaces). This also means % must be written as %%. # # use 'login=PASS' if users must authenticate against # the upstream proxy or in the case of a reverse proxy # configuration, the origin web server. This will pass # the users credentials as they are to the peer. # Note: To combine this with local authentication the Basic # authentication scheme must be used, and both servers must # share the same user database as HTTP only allows for # a single login (one for proxy, one for origin server). # Also be warned this will expose your users proxy # password to the peer. USE WITH CAUTION # # use 'login=*:password' to pass the username to the # upstream cache, but with a fixed password. This is meant # to be used when the peer is in another administrative # domain, but it is still needed to identify each user. # The star can optionally be followed by some extra # information which is added to the username. This can # be used to identify this proxy to the peer, similar to # the login=username:password option above. # # use 'connect-timeout=nn' to specify a peer # specific connect timeout (also see the # peer_connect_timeout directive) # # use 'digest-url=url' to tell Squid to fetch the cache # digest (if digests are enabled) for this host from # the specified URL rather than the Squid default # location. # # use 'allow-miss' to disable Squid's use of only-if-cached # when forwarding requests to siblings. This is primarily # useful when icp_hit_stale is used by the sibling. To # extensive use of this option may result in forwarding # loops, and you should avoid having two-way peerings # with this option. (for example to deny peer usage on # requests from peer by denying cache_peer_access if the # source is a peer) # # use 'max-conn=n' to limit the amount of connections Squid # may open to this peer. # # use 'htcp' to send HTCP, instead of ICP, queries # to the neighbor. You probably also want to # set the "icp port" to 4827 instead of 3130. # You must also allow this Squid htcp_access and # http_access in the peer Squid configuration. # # use 'htcp-oldsquid' to send HTCP to old Squid versions # You must also allow this Squid htcp_access and # http_access in the peer Squid configuration. # # 'originserver' causes this parent peer to be contacted as # a origin server. Meant to be used in accelerator setups. # # use 'userhash' to load-balance amongst a set of parents # based on the client proxy_auth or ident username. # # use 'sourcehash' to load-balance amongst a set of parents # based on the client source ip. # # use 'name=xxx' if you have multiple peers on the same # host but different ports. This name can be used to # differentiate the peers in cache_peer_access and similar # directives. # # use 'monitorurl=url' to have periodically request a given # URL from the peer, and only consider the peer as alive # if this monitoring is successful (default none) # # use 'monitorsize=min[-max]' to limit the size range of # 'monitorurl' replies considered valid. Defaults to 0 to # accept any size replies as valid. # # use 'monitorinterval=seconds' to change frequency of # how often the peer is monitored with 'monitorurl' # (default 300 for a 5 minute interval). If set to 0 # then monitoring is disabled even if a URL is defined. # # use 'monitortimeout=seconds' to change the timeout of # 'monitorurl'. Defaults to 'monitorinterval'. # # use 'forceddomain=name' to forcibly set the Host header # of requests forwarded to this peer. Useful in accelerator # setups where the server (peer) expects a certain domain # name and using redirectors to feed this domain name # is not feasible. # # use 'ssl' to indicate connections to this peer should # be SSL/TLS encrypted. # # use 'sslcert=/path/to/ssl/certificate' to specify a client # SSL certificate to use when connecting to this peer. # # use 'sslkey=/path/to/ssl/key' to specify the private SSL # key corresponding to sslcert above. If 'sslkey' is not # specified 'sslcert' is assumed to reference a # combined file containing both the certificate and the key. # # use sslversion=1|2|3|4 to specify the SSL version to use # when connecting to this peer # 1 = automatic (default) # 2 = SSL v2 only # 3 = SSL v3 only # 4 = TLS v1 only # # use sslcipher=... to specify the list of valid SSL ciphers # to use when connecting to this peer. # # use ssloptions=... to specify various SSL engine options: # NO_SSLv2 Disallow the use of SSLv2 # NO_SSLv3 Disallow the use of SSLv3 # NO_TLSv1 Disallow the use of TLSv1 # See src/ssl_support.c or the OpenSSL documentation for # a more complete list. # # use sslcafile=... to specify a file containing # additional CA certificates to use when verifying the # peer certificate. # # use sslcapath=... to specify a directory containing # additional CA certificates to use when verifying the # peer certificate. # # use sslcrlfile=... to specify a certificate revocation # list file to use when verifying the peer certificate. # # use sslflags=... to specify various flags modifying the # SSL implementation: # DONT_VERIFY_PEER # Accept certificates even if they fail to # verify. # NO_DEFAULT_CA # Don't use the default CA list built in # to OpenSSL. # # use ssldomain= to specify the peer name as advertised # in it's certificate. Used for verifying the correctness # of the received peer certificate. If not specified the # peer hostname will be used. # # use front-end-https to enable the "Front-End-Https: On" # header needed when using Squid as a SSL frontend in front # of Microsoft OWA. See MS KB document Q307347 for details # on this header. If set to auto the header will # only be added if the request is forwarded as a https:// # URL. # # use connection-auth=off to tell Squid that this peer does # not support Microsoft connection oriented authentication, # and any such challenges received from there should be # ignored. Default is auto to automatically determine the # status of the peer. # # use idle=n to specify a minimum number of idle connections # that should be kept open to this peer. # # use http11 to send requests using HTTP/1.1 to this peer. # Note: The HTTP/1.1 support is still incomplete, with an # internal HTTP/1.0 hop. As result 1xx responses will not # be forwarded. # #Default: # none # TAG: cache_peer_domain # Use to limit the domains for which a neighbor cache will be # queried. Usage: # # cache_peer_domain cache-host domain [domain ...] # cache_peer_domain cache-host !domain # # For example, specifying # # cache_peer_domain parent.foo.net .edu # # has the effect such that UDP query packets are sent to # 'bigserver' only when the requested object exists on a # server in the .edu domain. Prefixing the domain name # with '!' means the cache will be queried for objects # NOT in that domain. # # NOTE: * Any number of domains may be given for a cache-host, # either on the same or separate lines. # * When multiple domains are given for a particular # cache-host, the first matched domain is applied. # * Cache hosts with no domain restrictions are queried # for all requests. # * There are no defaults. # * There is also a 'cache_peer_access' tag in the ACL # section. # #Default: # none # TAG: cache_peer_access # Similar to 'cache_peer_domain' but provides more flexibility by # using ACL elements. # # cache_peer_access cache-host allow|deny [!]aclname ... # # The syntax is identical to 'http_access' and the other lists of # ACL elements. See the comments for 'http_access' below, or # the Squid FAQ (http://www.squid-cache.org/FAQ/FAQ-10.html). # #Default: # none # TAG: neighbor_type_domain # usage: neighbor_type_domain neighbor parent|sibling domain domain ... # # Modifying the neighbor type for specific domains is now # possible. You can treat some domains differently than the the # default neighbor type specified on the 'cache_peer' line. # Normally it should only be necessary to list domains which # should be treated differently because the default neighbor type # applies for hostnames which do not match domains listed here. # #EXAMPLE: # cache_peer cache.foo.org parent 3128 3130 # neighbor_type_domain cache.foo.org sibling .com .net # neighbor_type_domain cache.foo.org sibling .au .de # #Default: # none # TAG: dead_peer_timeout (seconds) # This controls how long Squid waits to declare a peer cache # as "dead." If there are no ICP replies received in this # amount of time, Squid will declare the peer dead and not # expect to receive any further ICP replies. However, it # continues to send ICP queries, and will mark the peer as # alive upon receipt of the first subsequent ICP reply. # # This timeout also affects when Squid expects to receive ICP # replies from peers. If more than 'dead_peer' seconds have # passed since the last ICP reply was received, Squid will not # expect to receive an ICP reply on the next query. Thus, if # your time between requests is greater than this timeout, you # will see a lot of requests sent DIRECT to origin servers # instead of to your parents. # #Default: # dead_peer_timeout 10 seconds # TAG: hierarchy_stoplist # A list of words which, if found in a URL, cause the object to # be handled directly by this cache. In other words, use this # to not query neighbor caches for certain objects. You may # list this option multiple times. Note: never_direct overrides # this option. #We recommend you to use at least the following line. hierarchy_stoplist cgi-bin ? # MEMORY CACHE OPTIONS # ----------------------------------------------------------------------------- # TAG: cache_mem (bytes) # NOTE: THIS PARAMETER DOES NOT SPECIFY THE MAXIMUM PROCESS SIZE. # IT ONLY PLACES A LIMIT ON HOW MUCH ADDITIONAL MEMORY SQUID WILL # USE AS A MEMORY CACHE OF OBJECTS. SQUID USES MEMORY FOR OTHER # THINGS AS WELL. SEE THE SQUID FAQ SECTION 8 FOR DETAILS. # # 'cache_mem' specifies the ideal amount of memory to be used # for: # * In-Transit objects # * Hot Objects # * Negative-Cached objects # # Data for these objects are stored in 4 KB blocks. This # parameter specifies the ideal upper limit on the total size of # 4 KB blocks allocated. In-Transit objects take the highest # priority. # # In-transit objects have priority over the others. When # additional space is needed for incoming data, negative-cached # and hot objects will be released. In other words, the # negative-cached and hot objects will fill up any unused space # not needed for in-transit objects. # # If circumstances require, this limit will be exceeded. # Specifically, if your incoming request rate requires more than # 'cache_mem' of memory to hold in-transit objects, Squid will # exceed this limit to satisfy the new requests. When the load # decreases, blocks will be freed until the high-water mark is # reached. Thereafter, blocks will be used to store hot # objects. # #Default: # cache_mem 8 MB # TAG: maximum_object_size_in_memory (bytes) # Objects greater than this size will not be attempted to kept in # the memory cache. This should be set high enough to keep objects # accessed frequently in memory to improve performance whilst low # enough to keep larger objects from hoarding cache_mem. # #Default: # maximum_object_size_in_memory 8 KB # TAG: memory_replacement_policy # The memory replacement policy parameter determines which # objects are purged from memory when memory space is needed. # # See cache_replacement_policy for details. # #Default: # memory_replacement_policy lru # DISK CACHE OPTIONS # ----------------------------------------------------------------------------- # TAG: cache_replacement_policy # The cache replacement policy parameter determines which # objects are evicted (replaced) when disk space is needed. # # lru : Squid's original list based LRU policy # heap GDSF : Greedy-Dual Size Frequency # heap LFUDA: Least Frequently Used with Dynamic Aging # heap LRU : LRU policy implemented using a heap # # Applies to any cache_dir lines listed below this. # # The LRU policies keeps recently referenced objects. # # The heap GDSF policy optimizes object hit rate by keeping smaller # popular objects in cache so it has a better chance of getting a # hit. It achieves a lower byte hit rate than LFUDA though since # it evicts larger (possibly popular) objects. # # The heap LFUDA policy keeps popular objects in cache regardless of # their size and thus optimizes byte hit rate at the expense of # hit rate since one large, popular object will prevent many # smaller, slightly less popular objects from being cached. # # Both policies utilize a dynamic aging mechanism that prevents # cache pollution that can otherwise occur with frequency-based # replacement policies. # # NOTE: if using the LFUDA replacement policy you should increase # the value of maximum_object_size above its default of 4096 KB to # to maximize the potential byte hit rate improvement of LFUDA. # # For more information about the GDSF and LFUDA cache replacement # policies see http://www.hpl.hp.com/techreports/1999/HPL-1999-69.html # and http://fog.hpl.external.hp.com/techreports/98/HPL-98-173.html. # #Default: # cache_replacement_policy lru # TAG: cache_dir # Usage: # # cache_dir Type Directory-Name Fs-specific-data [options] # # You can specify multiple cache_dir lines to spread the # cache among different disk partitions. # # Type specifies the kind of storage system to use. Only "ufs" # is built by default. To enable any of the other storage systems # see the --enable-storeio configure option. # # 'Directory' is a top-level directory where cache swap # files will be stored. If you want to use an entire disk # for caching, this can be the mount-point directory. # The directory must exist and be writable by the Squid # process. Squid will NOT create this directory for you. # Only using COSS, a raw disk device or a stripe file can # be specified, but the configuration of the "cache_swap_log" # tag is mandatory. # # The ufs store type: # # "ufs" is the old well-known Squid storage format that has always # been there. # # cache_dir ufs Directory-Name Mbytes L1 L2 [options] # # 'Mbytes' is the amount of disk space (MB) to use under this # directory. The default is 100 MB. Change this to suit your # configuration. Do NOT put the size of your disk drive here. # Instead, if you want Squid to use the entire disk drive, # subtract 20% and use that value. # # 'Level-1' is the number of first-level subdirectories which # will be created under the 'Directory'. The default is 16. # # 'Level-2' is the number of second-level subdirectories which # will be created under each first-level directory. The default # is 256. # # The aufs store type: # # "aufs" uses the same storage format as "ufs", utilizing # POSIX-threads to avoid blocking the main Squid process on # disk-I/O. This was formerly known in Squid as async-io. # # cache_dir aufs Directory-Name Mbytes L1 L2 [options] # # see argument descriptions under ufs above # # The diskd store type: # # "diskd" uses the same storage format as "ufs", utilizing a # separate process to avoid blocking the main Squid process on # disk-I/O. # # cache_dir diskd Directory-Name Mbytes L1 L2 [options] [Q1=n] [Q2=n] # # see argument descriptions under ufs above # # Q1 specifies the number of unacknowledged I/O requests when Squid # stops opening new files. If this many messages are in the queues, # Squid won't open new files. Default is 64 # # Q2 specifies the number of unacknowledged messages when Squid # starts blocking. If this many messages are in the queues, # Squid blocks until it receives some replies. Default is 72 # # When Q1 < Q2 (the default), the cache directory is optimized # for lower response time at the expense of a decrease in hit # ratio. If Q1 > Q2, the cache directory is optimized for # higher hit ratio at the expense of an increase in response # time. # # The coss store type: # # block-size=n defines the "block size" for COSS cache_dir's. # Squid uses file numbers as block numbers. Since file numbers # are limited to 24 bits, the block size determines the maximum # size of the COSS partition. The default is 512 bytes, which # leads to a maximum cache_dir size of 512<<24, or 8 GB. Note # you should not change the COSS block size after Squid # has written some objects to the cache_dir. # # overwrite-percent=n defines the percentage of disk that COSS # must write to before a given object will be moved to the # current stripe. A value of "n" closer to 100 will cause COSS # to waste less disk space by having multiple copies of an object # on disk, but will increase the chances of overwriting a popular # object as COSS overwrites stripes. A value of "n" close to 0 # will cause COSS to keep all current objects in the current COSS # stripe at the expense of the hit rate. The default value of 50 # will allow any given object to be stored on disk a maximum of # 2 times. # # max-stripe-waste=n defines the maximum amount of space that COSS # will waste in a given stripe (in bytes). When COSS writes data # to disk, it will potentially waste up to "max-size" worth of disk # space for each 1MB of data written. If "max-size" is set to a # large value (ie >256k), this could potentially result in large # amounts of wasted disk space. Setting this value to a lower value # (ie 64k or 32k) will result in a COSS disk refusing to cache # larger objects until the COSS stripe has been filled to within # "max-stripe-waste" of the maximum size (1MB). # # membufs=n defines the number of "memory-only" stripes that COSS # will use. When an cache hit is performed on a COSS stripe before # COSS has reached the overwrite-percent value for that object, # COSS will use a series of memory buffers to hold the object in # while the data is sent to the client. This will define the maximum # number of memory-only buffers that COSS will use. The default value # is 10, which will use a maximum of 10MB of memory for buffers. # # maxfullbufs=n defines the maximum number of stripes a COSS partition # will have in memory waiting to be freed (either because the disk is # under load and the stripe is unwritten, or because clients are still # transferring data from objects using the memory). In order to try # and maintain a good hit rate under load, COSS will reserve the last # 2 full stripes for object hits. (ie a COSS cache_dir will reject # new objects when the number of full stripes is 2 less than maxfullbufs) # # The null store type: # # no options are allowed or required # # Common options: # # no-store, no new objects should be stored to this cache_dir # # min-size=n, refers to the min object size this storedir will accept. # It's used to restrict a storedir to only store large objects # (e.g. aufs) while other storedirs are optimized for smaller objects # (e.g. COSS). Defaults to 0. # # max-size=n, refers to the max object size this storedir supports. # It is used to initially choose the storedir to dump the object. # Note: To make optimal use of the max-size limits you should order # the cache_dir lines with the smallest max-size value first and the # ones with no max-size specification last. # # Note that for coss, max-size must be less than COSS_MEMBUF_SZ # (hard coded at 1 MB). # #Default: cache_dir ufs /var/spool/squid 100 16 10240 # TAG: store_dir_select_algorithm # Set this to 'round-robin' as an alternative. # #Default: # store_dir_select_algorithm least-load # TAG: max_open_disk_fds # To avoid having disk as the I/O bottleneck Squid can optionally # bypass the on-disk cache if more than this amount of disk file # descriptors are open. # # A value of 0 indicates no limit. # #Default: # max_open_disk_fds 0 # TAG: minimum_object_size (bytes) # Objects smaller than this size will NOT be saved on disk. The # value is specified in kilobytes, and the default is 0 KB, which # means there is no minimum. # #Default: # minimum_object_size 0 KB # TAG: maximum_object_size (bytes) # Objects larger than this size will NOT be saved on disk. The # value is specified in kilobytes, and the default is 4MB. If # you wish to get a high BYTES hit ratio, you should probably # increase this (one 32 MB object hit counts for 3200 10KB # hits). If you wish to increase speed more than your want to # save bandwidth you should leave this low. # # NOTE: if using the LFUDA replacement policy you should increase # this value to maximize the byte hit rate improvement of LFUDA! # See replacement_policy below for a discussion of this policy. # # NOTE 2: In Debian the default is raised to 20MB allowing cache # of Packages files in debian repositories. This makes squid a # proper proxy for APT. # #Default: #NOTE 3: raised to 50 MB maximum_object_size 51200 KB # TAG: cache_swap_low (percent, 0-100) # TAG: cache_swap_high (percent, 0-100) # # The low- and high-water marks for cache object replacement. # Replacement begins when the swap (disk) usage is above the # low-water mark and attempts to maintain utilization near the # low-water mark. As swap utilization gets close to high-water # mark object eviction becomes more aggressive. If utilization is # close to the low-water mark less replacement is done each time. # # Defaults are 90% and 95%. If you have a large cache, 5% could be # hundreds of MB. If this is the case you may wish to set these # numbers closer together. # #Default: # cache_swap_low 90 # cache_swap_high 95 # TAG: update_headers on|off # By default Squid updates stored HTTP headers when receiving # a 304 response. Set this to off if you want to disable this # for disk I/O performance reasons. Disabling this VIOLATES the # HTTP standard, and could make you liable for problems which it # causes. # #Default: # update_headers on # LOGFILE OPTIONS # ----------------------------------------------------------------------------- # TAG: logformat # Usage: # # logformat # # Defines an access log format. # # The is a string with embedded % format codes # # % format codes all follow the same basic structure where all but # the formatcode is optional. Output strings are automatically escaped # as required according to their context and the output format # modifiers are usually not needed, but can be specified if an explicit # output format is desired. # # % ["|[|'|#] [-] [[0]width] [{argument}] formatcode # # " output in quoted string format # [ output in squid text log format as used by log_mime_hdrs # # output in URL quoted format # ' output as-is # # - left aligned # width field width. If starting with 0 the # output is zero padded # {arg} argument such as header name etc # # Format codes: # # >a Client source IP address # >A Client FQDN # >p Client source port # h Request header. Optional header name argument # on the format header[:[separator]element] # h # un User name # ul User name from authentication # ui User name from ident # us User name from SSL # ue User name from external acl helper # Hs HTTP status code # Ss Squid request status (TCP_MISS etc) # Sh Squid hierarchy status (DEFAULT_PARENT etc) # mt MIME content type # rm Request method (GET/POST etc) # ru Request URL # rp Request URL-Path excluding hostname # rv Request protocol version # ea Log string returned by external acl # st Request size including HTTP headers # st Request+Reply size including HTTP headers # sn Unique sequence number per log line entry # % a literal % character # # The default formats available (which do not need re-defining) are: # #logformat squid %ts.%03tu %6tr %>a %Ss/%03Hs %a %Ss/%03Hs %h] [%a %ui %un [%tl] "%rm %ru HTTP/%rv" %Hs %a %ui %un [%tl] "%rm %ru HTTP/%rv" %Hs %h" "%{User-Agent}>h" %Ss:%Sh # #Default: # none # TAG: access_log # These files log client request activities. Has a line every HTTP or # ICP request. The format is: # access_log [ [acl acl ...]] # access_log none [acl acl ...]] # # Will log to the specified file using the specified format (which # must be defined in a logformat directive) those entries which match # ALL the acl's specified (which must be defined in acl clauses). # If no acl is specified, all requests will be logged to this file. # # To disable logging of a request use the filepath "none", in which case # a logformat name should not be specified. # # To log the request via syslog specify a filepath of "syslog": # # access_log syslog[:facility.priority] [format [acl1 [acl2 ....]]] # where facility could be any of: # authpriv, daemon, local0 .. local7 or user. # # And priority could be any of: # err, warning, notice, info, debug. access_log /var/log/squid/access.log squid # TAG: log_access allow|deny acl acl... # This options allows you to control which requests gets logged # to access.log (see access_log directive). Requests denied for # logging will also not be accounted for in performance counters. # #Default: # none # TAG: logfile_daemon # Specify the path to the logfile-writing daemon. This daemon is # used to write the access and store logs, if configured. # #Default: # logfile_daemon /usr/lib/squid/logfile-daemon # TAG: cache_log # Cache logging file. This is where general information about # your cache's behavior goes. You can increase the amount of data # logged to this file with the "debug_options" tag below. # #Default: # cache_log /var/log/squid/cache.log # TAG: cache_store_log # Logs the activities of the storage manager. Shows which # objects are ejected from the cache, and which objects are # saved and for how long. To disable, enter "none". There are # not really utilities to analyze this data, so you can safely # disable it. # #Default: # cache_store_log /var/log/squid/store.log # TAG: cache_swap_state # Location for the cache "swap.state" file. This index file holds # the metadata of objects saved on disk. It is used to rebuild # the cache during startup. Normally this file resides in each # 'cache_dir' directory, but you may specify an alternate # pathname here. Note you must give a full filename, not just # a directory. Since this is the index for the whole object # list you CANNOT periodically rotate it! # # If %s can be used in the file name it will be replaced with a # a representation of the cache_dir name where each / is replaced # with '.'. This is needed to allow adding/removing cache_dir # lines when cache_swap_log is being used. # # If have more than one 'cache_dir', and %s is not used in the name # these swap logs will have names such as: # # cache_swap_log.00 # cache_swap_log.01 # cache_swap_log.02 # # The numbered extension (which is added automatically) # corresponds to the order of the 'cache_dir' lines in this # configuration file. If you change the order of the 'cache_dir' # lines in this file, these index files will NOT correspond to # the correct 'cache_dir' entry (unless you manually rename # them). We recommend you do NOT use this option. It is # better to keep these index files in each 'cache_dir' directory. # #Default: # none # TAG: logfile_rotate # Specifies the number of logfile rotations to make when you # type 'squid -k rotate'. The default is 10, which will rotate # with extensions 0 through 9. Setting logfile_rotate to 0 will # disable the file name rotation, but the logfiles are still closed # and re-opened. This will enable you to rename the logfiles # yourself just before sending the rotate signal. # # Note, the 'squid -k rotate' command normally sends a USR1 # signal to the running squid process. In certain situations # (e.g. on Linux with Async I/O), USR1 is used for other # purposes, so -k rotate uses another signal. It is best to get # in the habit of using 'squid -k rotate' instead of 'kill -USR1 # '. # # Note2, for Debian/Linux the default of logfile_rotate is # zero, since it includes external logfile-rotation methods. # #Default: # logfile_rotate 0 # TAG: emulate_httpd_log on|off # The Cache can emulate the log file format which many 'httpd' # programs use. To disable/enable this emulation, set # emulate_httpd_log to 'off' or 'on'. The default # is to use the native log format since it includes useful # information Squid-specific log analyzers use. # #Default: # emulate_httpd_log off # TAG: log_ip_on_direct on|off # Log the destination IP address in the hierarchy log tag when going # direct. Earlier Squid versions logged the hostname here. If you # prefer the old way set this to off. # #Default: # log_ip_on_direct on # TAG: mime_table # Pathname to Squid's MIME table. You shouldn't need to change # this, but the default file contains examples and formatting # information if you do. # #Default: # mime_table /usr/share/squid/mime.conf # TAG: log_mime_hdrs on|off # The Cache can record both the request and the response MIME # headers for each HTTP transaction. The headers are encoded # safely and will appear as two bracketed fields at the end of # the access log (for either the native or httpd-emulated log # formats). To enable this logging set log_mime_hdrs to 'on'. # #Default: # log_mime_hdrs off # TAG: useragent_log # Squid will write the User-Agent field from HTTP requests # to the filename specified here. By default useragent_log # is disabled. # #Default: # none # TAG: referer_log # Squid will write the Referer field from HTTP requests to the # filename specified here. By default referer_log is disabled. # Note that "referer" is actually a misspelling of "referrer" # however the misspelt version has been accepted into the HTTP RFCs # and we accept both. # #Default: # none # TAG: pid_filename # A filename to write the process-id to. To disable, enter "none". # #Default: # pid_filename /var/run/squid.pid # TAG: debug_options # Logging options are set as section,level where each source file # is assigned a unique section. Lower levels result in less # output, Full debugging (level 9) can result in a very large # log file, so be careful. The magic word "ALL" sets debugging # levels for all sections. We recommend normally running with # "ALL,1". # #Default: # debug_options ALL,1 # TAG: log_fqdn on|off # Turn this on if you wish to log fully qualified domain names # in the access.log. To do this Squid does a DNS lookup of all # IP's connecting to it. This can (in some situations) increase # latency, which makes your cache seem slower for interactive # browsing. # #Default: # log_fqdn off # TAG: client_netmask # A netmask for client addresses in logfiles and cachemgr output. # Change this to protect the privacy of your cache clients. # A netmask of 255.255.255.0 will log all IP's in that range with # the last digit set to '0'. # #Default: # client_netmask 255.255.255.255 # TAG: forward_log # Note: This option is only available if Squid is rebuilt with the # --enable-forward-log option # # Logs the server-side requests. # # This is currently work in progress. # #Default: # none # TAG: strip_query_terms # By default, Squid strips query terms from requested URLs before # logging. This protects your user's privacy. # #Default: # strip_query_terms on # TAG: buffered_logs on|off # cache.log log file is written with stdio functions, and as such # it can be buffered or unbuffered. By default it will be unbuffered. # Buffering it can speed up the writing slightly (though you are # unlikely to need to worry unless you run with tons of debugging # enabled in which case performance will suffer badly anyway..). # #Default: # buffered_logs off # TAG: netdb_filename # A filename where Squid stores it's netdb state between restarts. # To disable, enter "none". # #Default: # netdb_filename /var/spool/squid/logs/netdb.state # OPTIONS FOR FTP GATEWAYING # ----------------------------------------------------------------------------- # TAG: ftp_user # If you want the anonymous login password to be more informative # (and enable the use of picky ftp servers), set this to something # reasonable for your domain, like wwwuser@somewhere.net # # The reason why this is domainless by default is the # request can be made on the behalf of a user in any domain, # depending on how the cache is used. # Some ftp server also validate the email address is valid # (for example perl.com). # #Default: # ftp_user Squid@ # TAG: ftp_list_width # Sets the width of ftp listings. This should be set to fit in # the width of a standard browser. Setting this too small # can cut off long filenames when browsing ftp sites. # #Default: # ftp_list_width 32 # TAG: ftp_passive # If your firewall does not allow Squid to use passive # connections, turn off this option. # #Default: # ftp_passive on # TAG: ftp_sanitycheck # For security and data integrity reasons Squid by default performs # sanity checks of the addresses of FTP data connections ensure the # data connection is to the requested server. If you need to allow # FTP connections to servers using another IP address for the data # connection turn this off. # #Default: # ftp_sanitycheck on # TAG: ftp_telnet_protocol # The FTP protocol is officially defined to use the telnet protocol # as transport channel for the control connection. However, many # implementations are broken and does not respect this aspect of # the FTP protocol. # # If you have trouble accessing files with ASCII code 255 in the # path or similar problems involving this ASCII code you can # try setting this directive to off. If that helps, report to the # operator of the FTP server in question that their FTP server # is broken and does not follow the FTP standard. # #Default: # ftp_telnet_protocol on # OPTIONS FOR EXTERNAL SUPPORT PROGRAMS # ----------------------------------------------------------------------------- # TAG: diskd_program # Specify the location of the diskd executable. # Note this is only useful if you have compiled in # diskd as one of the store io modules. # #Default: # diskd_program /usr/lib/squid/diskd-daemon # TAG: unlinkd_program # Specify the location of the executable for file deletion process. # #Default: # unlinkd_program /usr/lib/squid/unlinkd # TAG: pinger_program # Note: This option is only available if Squid is rebuilt with the # --enable-icmp option # # Specify the location of the executable for the pinger process. # #Default: # pinger_program /usr/lib/squid/pinger # OPTIONS FOR URL REWRITING # ----------------------------------------------------------------------------- # TAG: storeurl_rewrite_program # Specify the location of the executable for the Store URL rewriter. # The Store URL rewriter allows URLs to be "normalised" ; mapping # multiple URLs to a single URL representation for cache operations. # # For example, if you request an object at: # # http://srv1.example.com/image.gif # # and a subsequent request for: # # http://srv2.example.com/image.gif # # then Squid will treat these both as different URLs and cache them # seperately. # # This is almost the normal case, but an increasing number of sites # distribute the same content between multiple frontend hosts. # The Store URL rewriter allows you to rewrite these URLs to one URL # to use for cache operations, but not -fetches-. Fetches are still # made from the original site, but stored with the store URL rewritten # URL as the store key. # # For each requested URL rewriter will receive on line with the format # # URL client_ip "/" fqdn user method urlgroup # [ kvpairs] # # In the future, the rewriter interface will be extended with # key=value pairs ("kvpairs" shown above). Rewriter programs # should be prepared to receive and possibly ignore additional # whitespace-separated tokens on each input line. # # And the rewriter may return a rewritten URL. The other components of # the request line does not need to be returned (ignored if they are). # # By default, a Store URL rewriter is not used. # # Please note - the normal URL rewriter rewrites Squid's _destination_ # URL - ie, what it fetches. The Store URL rewriter rewrites Squid's # _store_ URL - ie, what it uses to store and retrieve objects. # #Default: # none # TAG: storeurl_rewrite_children # # #Default: # storeurl_rewrite_children 5 # TAG: storeurl_rewrite_concurrency # # #Default: # storeurl_rewrite_concurrency 0 # TAG: url_rewrite_program # Specify the location of the executable for the URL rewriter. # Since they can perform almost any function there isn't one included. # # For each requested URL rewriter will receive on line with the format # # URL client_ip "/" fqdn user method urlgroup # [ kvpairs] # # In the future, the rewriter interface will be extended with # key=value pairs ("kvpairs" shown above). Rewriter programs # should be prepared to receive and possibly ignore additional # whitespace-separated tokens on each input line. # # And the rewriter may return a rewritten URL. The other components of # the request line does not need to be returned (ignored if they are). # # The rewriter can also indicate that a client-side redirect should # be performed to the new URL. This is done by prefixing the returned # URL with "301:" (moved permanently) or 302: (moved temporarily). # # It can also return a "urlgroup" that can subsequently be matched # in cache_peer_access and similar ACL driven rules. An urlgroup is # returned by prefixing the returned URL with "!urlgroup!". # # By default, a URL rewriter is not used. # #Default: # none # TAG: url_rewrite_children # The number of redirector processes to spawn. If you start # too few Squid will have to wait for them to process a backlog of # URLs, slowing it down. If you start too many they will use RAM # and other system resources. # #Default: # url_rewrite_children 5 # TAG: url_rewrite_concurrency # The number of requests each redirector helper can handle in # parallel. Defaults to 0 which indicates the redirector # is a old-style single threaded redirector. # # When this directive is set to a value >= 1 then the protocol # used to communicate with the helper is modified to include # a request ID in front of the request/response. The request # ID from the request must be echoed back with the response # to that request. # #Default: # url_rewrite_concurrency 0 # TAG: url_rewrite_host_header # By default Squid rewrites any Host: header in redirected # requests. If you are running an accelerator this may # not be a wanted effect of a redirector. # # WARNING: Entries are cached on the result of the URL rewriting # process, so be careful if you have domain-virtual hosts. # #Default: # url_rewrite_host_header on # TAG: url_rewrite_access # If defined, this access list specifies which requests are # sent to the redirector processes. By default all requests # are sent. # #Default: # none # TAG: storeurl_access # # #Default: # none # TAG: redirector_bypass # When this is 'on', a request will not go through the # redirector if all redirectors are busy. If this is 'off' # and the redirector queue grows too large, Squid will exit # with a FATAL error and ask you to increase the number of # redirectors. You should only enable this if the redirectors # are not critical to your caching system. If you use # redirectors for access control, and you enable this option, # users may have access to pages they should not # be allowed to request. # #Default: # redirector_bypass off # TAG: location_rewrite_program # Specify the location of the executable for the Location rewriter, # used to rewrite server generated redirects. Usually used in # conjunction with a url_rewrite_program # # For each Location header received the location rewriter will receive # one line with the format: # # location URL requested URL urlgroup # # And the rewriter may return a rewritten Location URL or a blank line. # The other components of the request line does not need to be returned # (ignored if they are). # # By default, a Location rewriter is not used. # #Default: # none # TAG: location_rewrite_children # The number of location rewriting processes to spawn. If you start # too few Squid will have to wait for them to process a backlog of # URLs, slowing it down. If you start too many they will use RAM # and other system resources. # #Default: # location_rewrite_children 5 # TAG: location_rewrite_concurrency # The number of requests each Location rewriter helper can handle in # parallel. Defaults to 0 which indicates that the helper # is a old-style singlethreaded helper. # #Default: # location_rewrite_concurrency 0 # TAG: location_rewrite_access # If defined, this access list specifies which requests are # sent to the location rewriting processes. By default all Location # headers are sent. # #Default: # none # OPTIONS FOR TUNING THE CACHE # ----------------------------------------------------------------------------- # TAG: cache # A list of ACL elements which, if matched, cause the request to # not be satisfied from the cache and the reply to not be cached. # In other words, use this to force certain objects to never be cached. # # You must use the word 'DENY' to indicate the ACL names which should # NOT be cached. # # Default is to allow all to be cached. # #Default: # none # TAG: max_stale time-units # This option puts an upper limit on how stale content Squid # will serve from the cache if cache validation fails. # #Default: # max_stale 1 week # TAG: refresh_pattern # usage: refresh_pattern [-i] regex min percent max [options] # # By default, regular expressions are CASE-SENSITIVE. To make # them case-insensitive, use the -i option. # # 'Min' is the time (in minutes) an object without an explicit # expiry time should be considered fresh. The recommended # value is 0, any higher values may cause dynamic applications # to be erroneously cached unless the application designer # has taken the appropriate actions. # # 'Percent' is a percentage of the objects age (time since last # modification age) an object without explicit expiry time # will be considered fresh. # # 'Max' is an upper limit on how long objects without an explicit # expiry time will be considered fresh. # # options: override-expire # override-lastmod # reload-into-ims # ignore-reload # ignore-no-cache # ignore-private # ignore-auth # stale-while-revalidate=NN # ignore-stale-while-revalidate # max-stale=NN # negative-ttl=NN # # override-expire enforces min age even if the server # sent an explicit expiry time (e.g., with the # Expires: header or Cache-Control: max-age). Doing this # VIOLATES the HTTP standard. Enabling this feature # could make you liable for problems which it causes. # # Note: this does not enforce staleness - it only extends # freshness / min. If the server returns a Expires time which # is longer than your max time, Squid will still consider # the object fresh for that period of time. # # override-lastmod enforces min age even on objects # that were modified recently. # # reload-into-ims changes client no-cache or ``reload'' # to If-Modified-Since requests. Doing this VIOLATES the # HTTP standard. Enabling this feature could make you # liable for problems which it causes. # # ignore-reload ignores a client no-cache or ``reload'' # header. Doing this VIOLATES the HTTP standard. Enabling # this feature could make you liable for problems which # it causes. # # ignore-no-cache ignores any ``Pragma: no-cache'' and # ``Cache-control: no-cache'' headers received from a server. # The HTTP RFC never allows the use of this (Pragma) header # from a server, only a client, though plenty of servers # send it anyway. # # ignore-private ignores any ``Cache-control: private'' # headers received from a server. Doing this VIOLATES # the HTTP standard. Enabling this feature could make you # liable for problems which it causes. # # ignore-auth caches responses to requests with authorization, # as if the originserver had sent ``Cache-control: public'' # in the response header. Doing this VIOLATES the HTTP standard. # Enabling this feature could make you liable for problems which # it causes. # # stale-while-revalidate=NN makes Squid perform an asyncronous # cache validation if the object isn't more stale than NN. # Doing this VIOLATES the HTTP standard. Enabling this # feature could make you liable for problems which it # causes. # # ignore-stale-while-revalidate makes Squid ignore any 'Cache-Control: # stale-while-revalidate=NN' headers received from a server. Can be # combined with stale-while-revalidate=NN to override the server provided # value. # # max-stale=NN provided a maximum staleness factor. Squid won't # serve objects more stale than this even if it failed to # validate the object. # # negative-ttl=NN overrides the global negative_ttl parameter # selectively for URLs matching this pattern (in seconds). # # Basically a cached object is: # # FRESH if expires < now, else STALE # STALE if age > max # FRESH if lm-factor < percent, else STALE # FRESH if age < min # else STALE # # The refresh_pattern lines are checked in the order listed here. # The first entry which matches is used. If none of the entries # match the default will be used. # # Note, you must uncomment all the default lines if you want # to change one. The default setting is only active if none is # used. # #Suggested default: refresh_pattern ^ftp: 1440 20% 10080 refresh_pattern ^gopher: 1440 0% 1440 refresh_pattern -i (/cgi-bin/|\?) 0 0% 0 refresh_pattern (Release|Packages(.gz)*)$ 0 20% 2880 refresh_pattern . 0 20% 4320 # TAG: quick_abort_min (KB) # TAG: quick_abort_max (KB) # TAG: quick_abort_pct (percent) # The cache by default continues downloading aborted requests # which are almost completed (less than 16 KB remaining). This # may be undesirable on slow (e.g. SLIP) links and/or very busy # caches. Impatient users may tie up file descriptors and # bandwidth by repeatedly requesting and immediately aborting # downloads. # # When the user aborts a request, Squid will check the # quick_abort values to the amount of data transfered until # then. # # If the transfer has less than 'quick_abort_min' KB remaining, # it will finish the retrieval. # # If the transfer has more than 'quick_abort_max' KB remaining, # it will abort the retrieval. # # If more than 'quick_abort_pct' of the transfer has completed, # it will finish the retrieval. # # If you do not want any retrieval to continue after the client # has aborted, set both 'quick_abort_min' and 'quick_abort_max' # to '0 KB'. # # If you want retrievals to always continue if they are being # cached set 'quick_abort_min' to '-1 KB'. # #Default: # quick_abort_min 16 KB # quick_abort_max 16 KB # quick_abort_pct 95 # TAG: read_ahead_gap buffer-size # The amount of data the cache will buffer ahead of what has been # sent to the client when retrieving an object from another server. # #Default: # read_ahead_gap 16 KB # TAG: negative_ttl time-units # Time-to-Live (TTL) for failed requests. Certain types of # failures (such as "connection refused" and "404 Not Found") are # negatively-cached for a configurable amount of time. The # default is 5 minutes. Note that this is different from # negative caching of DNS lookups. # #Default: # negative_ttl 5 minutes # TAG: positive_dns_ttl time-units # Upper limit on how long Squid will cache positive DNS responses. # Default is 6 hours (360 minutes). This directive must be set # larger than negative_dns_ttl. # #Default: # positive_dns_ttl 6 hours # TAG: negative_dns_ttl time-units # Time-to-Live (TTL) for negative caching of failed DNS lookups. # This also sets the lower cache limit on positive lookups. # Minimum value is 1 second, and it is not recommendable to go # much below 10 seconds. # #Default: # negative_dns_ttl 1 minute # TAG: range_offset_limit (bytes) # Sets a upper limit on how far into the the file a Range request # may be to cause Squid to prefetch the whole file. If beyond this # limit Squid forwards the Range request as it is and the result # is NOT cached. # # This is to stop a far ahead range request (lets say start at 17MB) # from making Squid fetch the whole object up to that point before # sending anything to the client. # # A value of -1 causes Squid to always fetch the object from the # beginning so it may cache the result. (2.0 style) # # A value of 0 causes Squid to never fetch more than the # client requested. (default) # #Default: # range_offset_limit 0 KB # TAG: minimum_expiry_time (seconds) # The minimum caching time according to (Expires - Date) # Headers Squid honors if the object can't be revalidated # defaults to 60 seconds. In reverse proxy enorinments it # might be desirable to honor shorter object lifetimes. It # is most likely better to make your server return a # meaningful Last-Modified header however. # #Default: # minimum_expiry_time 60 seconds # TAG: store_avg_object_size (kbytes) # Average object size, used to estimate number of objects your # cache can hold. The default is 13 KB. # #Default: # store_avg_object_size 13 KB # TAG: store_objects_per_bucket # Target number of objects per bucket in the store hash table. # Lowering this value increases the total number of buckets and # also the storage maintenance rate. The default is 20. # #Default: # store_objects_per_bucket 20 # HTTP OPTIONS # ----------------------------------------------------------------------------- # TAG: request_header_max_size (KB) # This specifies the maximum size for HTTP headers in a request. # Request headers are usually relatively small (about 512 bytes). # Placing a limit on the request header size will catch certain # bugs (for example with persistent connections) and possibly # buffer-overflow or denial-of-service attacks. # #Default: # request_header_max_size 20 KB # TAG: reply_header_max_size (KB) # This specifies the maximum size for HTTP headers in a reply. # Reply headers are usually relatively small (about 512 bytes). # Placing a limit on the reply header size will catch certain # bugs (for example with persistent connections) and possibly # buffer-overflow or denial-of-service attacks. # #Default: # reply_header_max_size 20 KB # TAG: request_body_max_size (KB) # This specifies the maximum size for an HTTP request body. # In other words, the maximum size of a PUT/POST request. # A user who attempts to send a request with a body larger # than this limit receives an "Invalid Request" error message. # If you set this parameter to a zero (the default), there will # be no limit imposed. # #Default: # request_body_max_size 0 KB # TAG: broken_posts # A list of ACL elements which, if matched, causes Squid to send # an extra CRLF pair after the body of a PUT/POST request. # # Some HTTP servers has broken implementations of PUT/POST, # and rely on an extra CRLF pair sent by some WWW clients. # # Quote from RFC2616 section 4.1 on this matter: # # Note: certain buggy HTTP/1.0 client implementations generate an # extra CRLF's after a POST request. To restate what is explicitly # forbidden by the BNF, an HTTP/1.1 client must not preface or follow # a request with an extra CRLF. # #Example: # acl buggy_server url_regex ^http://.... # broken_posts allow buggy_server # #Default: # none # TAG: upgrade_http0.9 # This access list controls when HTTP/0.9 responses is upgraded # to our current HTTP version. The default is to always upgrade. # # Some applications expect to be able to respond with non-HTTP # responses and clients gets confused if the response is upgraded. # For example SHOUTcast servers used for mp3 streaming. # # To enable some flexibility in detection of such applications # the first line of the response is available in the internal header # X-HTTP09-First-Line for use in the rep_header acl. # # Don't upgrade ShoutCast responses to HTTP acl shoutcast rep_header X-HTTP09-First-Line ^ICY.[0-9] upgrade_http0.9 deny shoutcast # TAG: via on|off # If set (default), Squid will include a Via header in requests and # replies as required by RFC2616. # #Default: # via on # TAG: cache_vary # When 'cache_vary' is set to off, response that have a # Vary header will not be stored in the cache. # #Default: # cache_vary on # TAG: broken_vary_encoding # Many servers have broken support for on-the-fly Content-Encoding, # returning the same ETag on both plain and gzip:ed variants. # Vary replies matching this access list will have the cache split # on the Accept-Encoding header of the request and not trusting the # ETag to be unique. # # Apache mod_gzip and mod_deflate known to be broken so don't trust # Apache to signal ETag correctly on such responses acl apache rep_header Server ^Apache broken_vary_encoding allow apache # TAG: collapsed_forwarding (on|off) # This option enables multiple requests for the same URI to be # processed as one request. Normally disabled to avoid increased # latency on dynamic content, but there can be benefit from enabling # this in accelerator setups where the web servers are the bottleneck # and reliable and returns mostly cacheable information. # #Default: # collapsed_forwarding off # TAG: refresh_stale_hit (time) # This option changes the refresh algorithm to allow concurrent # requests while an object is being refreshed to be processed as # cache hits if the object expired less than X seconds ago. Default # is 0 to disable this feature. This option is mostly interesting # in accelerator setups where a few objects is accessed very # frequently. # #Default: # refresh_stale_hit 0 seconds # TAG: ie_refresh on|off # Microsoft Internet Explorer up until version 5.5 Service # Pack 1 has an issue with transparent proxies, wherein it # is impossible to force a refresh. Turning this on provides # a partial fix to the problem, by causing all IMS-REFRESH # requests from older IE versions to check the origin server # for fresh content. This reduces hit ratio by some amount # (~10% in my experience), but allows users to actually get # fresh content when they want it. Note because Squid # cannot tell if the user is using 5.5 or 5.5SP1, the behavior # of 5.5 is unchanged from old versions of Squid (i.e. a # forced refresh is impossible). Newer versions of IE will, # hopefully, continue to have the new behavior and will be # handled based on that assumption. This option defaults to # the old Squid behavior, which is better for hit ratios but # worse for clients using IE, if they need to be able to # force fresh content. # #Default: # ie_refresh off # TAG: vary_ignore_expire on|off # Many HTTP servers supporting Vary gives such objects # immediate expiry time with no cache-control header # when requested by a HTTP/1.0 client. This option # enables Squid to ignore such expiry times until # HTTP/1.1 is fully implemented. # WARNING: This may eventually cause some varying # objects not intended for caching to get cached. # #Default: # vary_ignore_expire off # TAG: extension_methods # Squid only knows about standardized HTTP request methods. # You can add up to 20 additional "extension" methods here. extension_methods REPORT MERGE MKACTIVITY CHECKOUT # TAG: request_entities # Squid defaults to deny GET and HEAD requests with request entities, # as the meaning of such requests are undefined in the HTTP standard # even if not explicitly forbidden. # # Set this directive to on if you have clients which insists # on sending request entities in GET or HEAD requests. But be warned # that there is server software (both proxies and web servers) which # can fail to properly process this kind of request which may make you # vulnerable to cache pollution attacks if enabled. # #Default: # request_entities off # TAG: header_access # Usage: header_access header_name allow|deny [!]aclname ... # # WARNING: Doing this VIOLATES the HTTP standard. Enabling # this feature could make you liable for problems which it # causes. # # This option replaces the old 'anonymize_headers' and the # older 'http_anonymizer' option with something that is much # more configurable. This new method creates a list of ACLs # for each header, allowing you very fine-tuned header # mangling. # # You can only specify known headers for the header name. # Other headers are reclassified as 'Other'. You can also # refer to all the headers with 'All'. # # For example, to achieve the same behavior as the old # 'http_anonymizer standard' option, you should use: # # header_access From deny all # header_access Referer deny all # header_access Server deny all # header_access User-Agent deny all # header_access WWW-Authenticate deny all # header_access Link deny all # # Or, to reproduce the old 'http_anonymizer paranoid' feature # you should use: # # header_access Allow allow all # header_access Authorization allow all # header_access WWW-Authenticate allow all # header_access Proxy-Authorization allow all # header_access Proxy-Authenticate allow all # header_access Cache-Control allow all # header_access Content-Encoding allow all # header_access Content-Length allow all # header_access Content-Type allow all # header_access Date allow all # header_access Expires allow all # header_access Host allow all # header_access If-Modified-Since allow all # header_access Last-Modified allow all # header_access Location allow all # header_access Pragma allow all # header_access Accept allow all # header_access Accept-Charset allow all # header_access Accept-Encoding allow all # header_access Accept-Language allow all # header_access Content-Language allow all # header_access Mime-Version allow all # header_access Retry-After allow all # header_access Title allow all # header_access Connection allow all # header_access Proxy-Connection allow all # header_access All deny all # # By default, all headers are allowed (no anonymizing is # performed). # #Default: # none # TAG: header_replace # Usage: header_replace header_name message # Example: header_replace User-Agent Nutscrape/1.0 (CP/M; 8-bit) # # This option allows you to change the contents of headers # denied with header_access above, by replacing them with # some fixed string. This replaces the old fake_user_agent # option. # # By default, headers are removed if denied. # #Default: # none # TAG: relaxed_header_parser on|off|warn # In the default "on" setting Squid accepts certain forms # of non-compliant HTTP messages where it is unambiguous # what the sending application intended even if the message # is not correctly formatted. The messages is then normalized # to the correct form when forwarded by Squid. # # If set to "warn" then a warning will be emitted in cache.log # each time such HTTP error is encountered. # # If set to "off" then such HTTP errors will cause the request # or response to be rejected. # #Default: # relaxed_header_parser on # TAG: server_http11 on|off # This option enables the use ot HTTP/1.1 on outgoing "direct" requests. # See also the http11 cache_peer option. # Note: The HTTP/1.1 support is still incomplete, with an # internal HTTP/1.0 hop. As result 1xx responses will not # be forwarded. # #Default: # server_http11 off # TAG: ignore_expect_100 on|off # This option makes Squid ignore any Expect: 100-continue header present # in the request. # Note: Enabling this is a HTTP protocol violation, but some client may # not handle it well.. # #Default: # ignore_expect_100 off # TAG: external_refresh_check # This option defines an external helper for determining whether to # refresh a stale response. It will be called when Squid receives a # request for a cached response that is stale; the helper can either # confirm that the response is stale with a STALE response, or # extend the freshness of the response (thereby avoiding a refresh # check) with a FRESH response, along with a freshness=nnn keyword. # # external_refresh_check [options] FORMAT.. /path/to/helper [helper_args] # # If present, helper_args will be passed to the helper on the command # line verbatim. # # Options: # # children=n Number of processes to spawn to service external # refresh checks (default 5). # concurrency=n Concurrency level per process. Only used with # helpers capable of processing more than one query # at a time. # # When using the concurrency option, the protocol is changed by introducing # a query channel tag infront of the request/response. The query channel # tag is a number between 0 and concurrency-1. # # FORMAT specifications: # # %CACHE_URI The URI of the cached response # %RES{Header} HTTP response header value # %AGE The age of the cached response # # The request sent to the helper consists of the data in the format # specification in the order specified. # # The helper receives lines per the above format specification, and # returns lines starting with OK or ERR indicating the validity of # the request and optionally followed by additional keywords with # more details. URL escaping is used to protect each value in both # requests and responses. # # General result syntax: # # FRESH / STALE keyword=value ... # # Defined keywords: # # freshness=nnn The number of seconds to extend the freshness of # the response by. # log=string String to be logged in access.log. Available as # %ef in logformat specifications. # res{Header}=value # Value to update response headers with. If already # present, the supplied value completely replaces # the cached value. # # In the event of a helper-related error (e.g., overload), Squid # will always default to STALE. # #Default: # none # TIMEOUTS # ----------------------------------------------------------------------------- # TAG: forward_timeout time-units # This parameter specifies how long Squid should at most attempt in # finding a forwarding path for the request before giving up. # #Default: # forward_timeout 4 minutes # TAG: connect_timeout time-units # This parameter specifies how long to wait for the TCP connect to # the requested server or peer to complete before Squid should # attempt to find another path where to forward the request. # #Default: # connect_timeout 1 minute # TAG: peer_connect_timeout time-units # This parameter specifies how long to wait for a pending TCP # connection to a peer cache. The default is 30 seconds. You # may also set different timeout values for individual neighbors # with the 'connect-timeout' option on a 'cache_peer' line. # #Default: # peer_connect_timeout 30 seconds # TAG: read_timeout time-units # The read_timeout is applied on server-side connections. After # each successful read(), the timeout will be extended by this # amount. If no data is read again after this amount of time, # the request is aborted and logged with ERR_READ_TIMEOUT. The # default is 15 minutes. # #Default: # read_timeout 15 minutes # TAG: request_timeout # How long to wait for an HTTP request after initial # connection establishment. # #Default: # request_timeout 5 minutes # TAG: persistent_request_timeout # How long to wait for the next HTTP request on a persistent # connection after the previous request completes. # #Default: # persistent_request_timeout 2 minutes # TAG: client_lifetime time-units # The maximum amount of time a client (browser) is allowed to # remain connected to the cache process. This protects the Cache # from having a lot of sockets (and hence file descriptors) tied up # in a CLOSE_WAIT state from remote clients that go away without # properly shutting down (either because of a network failure or # because of a poor client implementation). The default is one # day, 1440 minutes. # # NOTE: The default value is intended to be much larger than any # client would ever need to be connected to your cache. You # should probably change client_lifetime only as a last resort. # If you seem to have many client connections tying up # filedescriptors, we recommend first tuning the read_timeout, # request_timeout, persistent_request_timeout and quick_abort values. # #Default: # client_lifetime 1 day # TAG: half_closed_clients # Some clients may shutdown the sending side of their TCP # connections, while leaving their receiving sides open. Sometimes, # Squid can not tell the difference between a half-closed and a # fully-closed TCP connection. By default, half-closed client # connections are kept open until a read(2) or write(2) on the # socket returns an error. Change this option to 'off' and Squid # will immediately close client connections when read(2) returns # "no more data to read." # #Default: # half_closed_clients on # TAG: pconn_timeout # Timeout for idle persistent connections to servers and other # proxies. # #Default: # pconn_timeout 1 minute # TAG: ident_timeout # Maximum time to wait for IDENT lookups to complete. # # If this is too high, and you enabled IDENT lookups from untrusted # users, you might be susceptible to denial-of-service by having # many ident requests going at once. # #Default: # ident_timeout 10 seconds # TAG: shutdown_lifetime time-units # When SIGTERM or SIGHUP is received, the cache is put into # "shutdown pending" mode until all active sockets are closed. # This value is the lifetime to set for all open descriptors # during shutdown mode. Any active clients after this many # seconds will receive a 'timeout' message. # #Default: # shutdown_lifetime 30 seconds # ADMINISTRATIVE PARAMETERS # ----------------------------------------------------------------------------- # TAG: cache_mgr # Email-address of local cache manager who will receive # mail if the cache dies. The default is "webmaster". # #Default: # cache_mgr webmaster # TAG: mail_from # From: email-address for mail sent when the cache dies. # The default is to use 'appname@unique_hostname'. # Default appname value is "squid", can be changed into # src/globals.h before building squid. # #Default: # none # TAG: mail_program # Email program used to send mail if the cache dies. # The default is "mail". The specified program must comply # with the standard Unix mail syntax: # mail-program recipient < mailfile # # Optional command line options can be specified. # #Default: # mail_program mail # TAG: cache_effective_user # If you start Squid as root, it will change its effective/real # UID/GID to the user specified below. The default is to change # to UID to proxy. If you define cache_effective_user, but not # cache_effective_group, Squid sets the GID to the effective # user's default group ID (taken from the password file) and # supplementary group list from the from groups membership of # cache_effective_user. # #Default: # cache_effective_user proxy # TAG: cache_effective_group # If you want Squid to run with a specific GID regardless of # the group memberships of the effective user then set this # to the group (or GID) you want Squid to run as. When set # all other group privileges of the effective user is ignored # and only this GID is effective. If Squid is not started as # root the user starting Squid must be member of the specified # group. # #Default: # none # TAG: httpd_suppress_version_string on|off # Suppress Squid version string info in HTTP headers and HTML error pages. # #Default: # httpd_suppress_version_string off # TAG: visible_hostname # If you want to present a special hostname in error messages, etc, # define this. Otherwise, the return value of gethostname() # will be used. If you have multiple caches in a cluster and # get errors about IP-forwarding you must set them to have individual # names with this setting. # #Default: # none # TAG: unique_hostname # If you want to have multiple machines with the same # 'visible_hostname' you must give each machine a different # 'unique_hostname' so forwarding loops can be detected. # #Default: # none # TAG: hostname_aliases # A list of other DNS names your cache has. # #Default: # none # TAG: umask # Minimum umask which should be enforced while the proxy # is running, in addition to the umask set at startup. # # Note: Should start with a 0 to indicate the normal octal # representation of umasks # #Default: # umask 027 # OPTIONS FOR THE CACHE REGISTRATION SERVICE # ----------------------------------------------------------------------------- # # This section contains parameters for the (optional) cache # announcement service. This service is provided to help # cache administrators locate one another in order to join or # create cache hierarchies. # # An 'announcement' message is sent (via UDP) to the registration # service by Squid. By default, the announcement message is NOT # SENT unless you enable it with 'announce_period' below. # # The announcement message includes your hostname, plus the # following information from this configuration file: # # http_port # icp_port # cache_mgr # # All current information is processed regularly and made # available on the Web at http://www.ircache.net/Cache/Tracker/. # TAG: announce_period # This is how frequently to send cache announcements. The # default is `0' which disables sending the announcement # messages. # # To enable announcing your cache, just uncomment the line # below. # #Default: # announce_period 0 # #To enable announcing your cache, just uncomment the line below. #announce_period 1 day # TAG: announce_host # TAG: announce_file # TAG: announce_port # announce_host and announce_port set the hostname and port # number where the registration message will be sent. # # Hostname will default to 'tracker.ircache.net' and port will # default default to 3131. If the 'filename' argument is given, # the contents of that file will be included in the announce # message. # #Default: # announce_host tracker.ircache.net # announce_port 3131 # HTTPD-ACCELERATOR OPTIONS # ----------------------------------------------------------------------------- # TAG: httpd_accel_no_pmtu_disc on|off # In many setups of transparently intercepting proxies Path-MTU # discovery can not work on traffic towards the clients. This is # the case when the intercepting device does not fully track # connections and fails to forward ICMP must fragment messages # to the cache server. # # If you have such setup and experience that certain clients # sporadically hang or never complete requests set this to on. # #Default: # httpd_accel_no_pmtu_disc off # DELAY POOL PARAMETERS # ----------------------------------------------------------------------------- # TAG: delay_pools # This represents the number of delay pools to be used. For example, # if you have one class 2 delay pool and one class 3 delays pool, you # have a total of 2 delay pools. # #Default: # delay_pools 0 # TAG: delay_class # This defines the class of each delay pool. There must be exactly one # delay_class line for each delay pool. For example, to define two # delay pools, one of class 2 and one of class 3, the settings above # and here would be: # #Example: # delay_pools 2 # 2 delay pools # delay_class 1 2 # pool 1 is a class 2 pool # delay_class 2 3 # pool 2 is a class 3 pool # # The delay pool classes are: # # class 1 Everything is limited by a single aggregate # bucket. # # class 2 Everything is limited by a single aggregate # bucket as well as an "individual" bucket chosen # from bits 25 through 32 of the IP address. # # class 3 Everything is limited by a single aggregate # bucket as well as a "network" bucket chosen # from bits 17 through 24 of the IP address and a # "individual" bucket chosen from bits 17 through # 32 of the IP address. # # NOTE: If an IP address is a.b.c.d # -> bits 25 through 32 are "d" # -> bits 17 through 24 are "c" # -> bits 17 through 32 are "c * 256 + d" # #Default: # none # TAG: delay_access # This is used to determine which delay pool a request falls into. # # delay_access is sorted per pool and the matching starts with pool 1, # then pool 2, ..., and finally pool N. The first delay pool where the # request is allowed is selected for the request. If it does not allow # the request to any pool then the request is not delayed (default). # # For example, if you want some_big_clients in delay # pool 1 and lotsa_little_clients in delay pool 2: # #Example: # delay_access 1 allow some_big_clients # delay_access 1 deny all # delay_access 2 allow lotsa_little_clients # delay_access 2 deny all # #Default: # none # TAG: delay_parameters # This defines the parameters for a delay pool. Each delay pool has # a number of "buckets" associated with it, as explained in the # description of delay_class. For a class 1 delay pool, the syntax is: # #delay_parameters pool aggregate # # For a class 2 delay pool: # #delay_parameters pool aggregate individual # # For a class 3 delay pool: # #delay_parameters pool aggregate network individual # # The variables here are: # # pool a pool number - ie, a number between 1 and the # number specified in delay_pools as used in # delay_class lines. # # aggregate the "delay parameters" for the aggregate bucket # (class 1, 2, 3). # # individual the "delay parameters" for the individual # buckets (class 2, 3). # # network the "delay parameters" for the network buckets # (class 3). # # A pair of delay parameters is written restore/maximum, where restore is # the number of bytes (not bits - modem and network speeds are usually # quoted in bits) per second placed into the bucket, and maximum is the # maximum number of bytes which can be in the bucket at any time. # # For example, if delay pool number 1 is a class 2 delay pool as in the # above example, and is being used to strictly limit each host to 64kbps # (plus overheads), with no overall limit, the line is: # #delay_parameters 1 -1/-1 8000/8000 # # Note that the figure -1 is used to represent "unlimited". # # And, if delay pool number 2 is a class 3 delay pool as in the above # example, and you want to limit it to a total of 256kbps (strict limit) # with each 8-bit network permitted 64kbps (strict limit) and each # individual host permitted 4800bps with a bucket maximum size of 64kb # to permit a decent web page to be downloaded at a decent speed # (if the network is not being limited due to overuse) but slow down # large downloads more significantly: # #delay_parameters 2 32000/32000 8000/8000 600/8000 # # There must be one delay_parameters line for each delay pool. # #Default: # none # TAG: delay_initial_bucket_level (percent, 0-100) # The initial bucket percentage is used to determine how much is put # in each bucket when squid starts, is reconfigured, or first notices # a host accessing it (in class 2 and class 3, individual hosts and # networks only have buckets associated with them once they have been # "seen" by squid). # #Default: # delay_initial_bucket_level 50 # WCCPv1 AND WCCPv2 CONFIGURATION OPTIONS # ----------------------------------------------------------------------------- # TAG: wccp_router # TAG: wccp2_router # Use this option to define your WCCP ``home'' router for # Squid. # # wccp_router supports a single WCCP(v1) router # # wccp2_router supports multiple WCCPv2 routers # # only one of the two may be used at the same time and defines # which version of WCCP to use. # #Default: # wccp_router 0.0.0.0 # TAG: wccp_version # This directive is only relevant if you need to set up WCCP(v1) # to some very old and end-of-life Cisco routers. In all other # setups it must be left unset or at the default setting. # It defines an internal version in the WCCP(v1) protocol, # with version 4 being the officially documented protocol. # # According to some users, Cisco IOS 11.2 and earlier only # support WCCP version 3. If you're using that or an earlier # version of IOS, you may need to change this value to 3, otherwise # do not specify this parameter. # #Default: # wccp_version 4 # TAG: wccp2_rebuild_wait # If this is enabled Squid will wait for the cache dir rebuild to finish # before sending the first wccp2 HereIAm packet # #Default: # wccp2_rebuild_wait on # TAG: wccp2_forwarding_method # WCCP2 allows the setting of forwarding methods between the # router/switch and the cache. Valid values are as follows: # # 1 - GRE encapsulation (forward the packet in a GRE/WCCP tunnel) # 2 - L2 redirect (forward the packet using Layer 2/MAC rewriting) # # Currently (as of IOS 12.4) cisco routers only support GRE. # Cisco switches only support the L2 redirect assignment method. # #Default: # wccp2_forwarding_method 1 # TAG: wccp2_return_method # WCCP2 allows the setting of return methods between the # router/switch and the cache for packets that the cache # decides not to handle. Valid values are as follows: # # 1 - GRE encapsulation (forward the packet in a GRE/WCCP tunnel) # 2 - L2 redirect (forward the packet using Layer 2/MAC rewriting) # # Currently (as of IOS 12.4) cisco routers only support GRE. # Cisco switches only support the L2 redirect assignment. # # If the "ip wccp redirect exclude in" command has been # enabled on the cache interface, then it is still safe for # the proxy server to use a l2 redirect method even if this # option is set to GRE. # #Default: # wccp2_return_method 1 # TAG: wccp2_assignment_method # WCCP2 allows the setting of methods to assign the WCCP hash # Valid values are as follows: # # 1 - Hash assignment # 2 - Mask assignment # # As a general rule, cisco routers support the hash assignment method # and cisco switches support the mask assignment method. # #Default: # wccp2_assignment_method 1 # TAG: wccp2_service # WCCP2 allows for multiple traffic services. There are two # types: "standard" and "dynamic". The standard type defines # one service id - http (id 0). The dynamic service ids can be from # 51 to 255 inclusive. In order to use a dynamic service id # one must define the type of traffic to be redirected; this is done # using the wccp2_service_info option. # # The "standard" type does not require a wccp2_service_info option, # just specifying the service id will suffice. # # MD5 service authentication can be enabled by adding # "password=" to the end of this service declaration. # # Examples: # # wccp2_service standard 0 # for the 'web-cache' standard service # wccp2_service dynamic 80 # a dynamic service type which will be # # fleshed out with subsequent options. # wccp2_service standard 0 password=foo # # #Default: # wccp2_service standard 0 # TAG: wccp2_service_info # Dynamic WCCPv2 services require further information to define the # traffic you wish to have diverted. # # The format is: # # wccp2_service_info protocol= flags=,.. # priority= ports=,.. # # The relevant WCCPv2 flags: # + src_ip_hash, dst_ip_hash # + source_port_hash, dst_port_hash # + src_ip_alt_hash, dst_ip_alt_hash # + src_port_alt_hash, dst_port_alt_hash # + ports_source # # The port list can be one to eight entries. # # Example: # # wccp2_service_info 80 protocol=tcp flags=src_ip_hash,ports_source # priority=240 ports=80 # # Note: the service id must have been defined by a previous # 'wccp2_service dynamic ' entry. # #Default: # none # TAG: wccp2_weight # Each cache server gets assigned a set of the destination # hash proportional to their weight. # #Default: # wccp2_weight 10000 # TAG: wccp_address # TAG: wccp2_address # Use this option if you require WCCP to use a specific # interface address. # # The default behavior is to not bind to any specific address. # #Default: # wccp_address 0.0.0.0 # wccp2_address 0.0.0.0 # PERSISTENT CONNECTION HANDLING # ----------------------------------------------------------------------------- # # Also see "pconn_timeout" in the TIMEOUTS section # TAG: client_persistent_connections # TAG: server_persistent_connections # Persistent connection support for clients and servers. By # default, Squid uses persistent connections (when allowed) # with its clients and servers. You can use these options to # disable persistent connections with clients and/or servers. # #Default: # client_persistent_connections on # server_persistent_connections on # TAG: persistent_connection_after_error # With this directive the use of persistent connections after # HTTP errors can be disabled. Useful if you have clients # who fail to handle errors on persistent connections proper. # #Default: # persistent_connection_after_error off # TAG: detect_broken_pconn # Some servers have been found to incorrectly signal the use # of HTTP/1.0 persistent connections even on replies not # compatible, causing significant delays. This server problem # has mostly been seen on redirects. # # By enabling this directive Squid attempts to detect such # broken replies and automatically assume the reply is finished # after 10 seconds timeout. # #Default: # detect_broken_pconn off # CACHE DIGEST OPTIONS # ----------------------------------------------------------------------------- # TAG: digest_generation # This controls whether the server will generate a Cache Digest # of its contents. # #Default: # digest_generation on # TAG: digest_bits_per_entry # This is the number of bits of the server's Cache Digest which # will be associated with the Digest entry for a given HTTP # Method and URL (public key) combination. The default is 5. # #Default: # digest_bits_per_entry 5 # TAG: digest_rebuild_period (seconds) # This is the wait time between Cache Digest rebuilds. # #Default: # digest_rebuild_period 1 hour # TAG: digest_rewrite_period (seconds) # This is the wait time between Cache Digest writes to disk. # #Default: # digest_rewrite_period 1 hour # TAG: digest_swapout_chunk_size (bytes) # This is the number of bytes of the Cache Digest to write to # disk at a time. It defaults to 4096 bytes (4KB), the Squid # default swap page. # #Default: # digest_swapout_chunk_size 4096 bytes # TAG: digest_rebuild_chunk_percentage (percent, 0-100) # This is the percentage of the Cache Digest to be scanned at a # time. By default it is set to 10% of the Cache Digest. # #Default: # digest_rebuild_chunk_percentage 10 # SNMP OPTIONS # ----------------------------------------------------------------------------- # TAG: snmp_port # Squid can now serve statistics and status information via SNMP. # By default it listens to port 3401 on the machine. If you don't # wish to use SNMP, set this to "0". # # Note: on Debian/Linux, the default is zero - you need to # set it to 3401 to enable it. # #Default: # snmp_port 0 # TAG: snmp_access # Allowing or denying access to the SNMP port. # # All access to the agent is denied by default. # usage: # # snmp_access allow|deny [!]aclname ... # #Example: # snmp_access allow snmppublic localhost # snmp_access deny all # #Default: # snmp_access deny all # TAG: snmp_incoming_address # TAG: snmp_outgoing_address # Just like 'udp_incoming_address' above, but for the SNMP port. # # snmp_incoming_address is used for the SNMP socket receiving # messages from SNMP agents. # snmp_outgoing_address is used for SNMP packets returned to SNMP # agents. # # The default snmp_incoming_address (0.0.0.0) is to listen on all # available network interfaces. # # If snmp_outgoing_address is set to 255.255.255.255 (the default) # it will use the same socket as snmp_incoming_address. Only # change this if you want to have SNMP replies sent using another # address than where this Squid listens for SNMP queries. # # NOTE, snmp_incoming_address and snmp_outgoing_address can not have # the same value since they both use port 3401. # #Default: # snmp_incoming_address 0.0.0.0 # snmp_outgoing_address 255.255.255.255 # ICP OPTIONS # ----------------------------------------------------------------------------- # TAG: icp_port # The port number where Squid sends and receives ICP queries to # and from neighbor caches. Default is 3130. To disable use # "0". May be overridden with -u on the command line. # #Default: # icp_port 3130 # TAG: htcp_port # The port number where Squid sends and receives HTCP queries to # and from neighbor caches. To turn it on you want to set it 4827. # By default it is set to "0" (disabled). # #Default: # htcp_port 0 # TAG: log_icp_queries on|off # If set, ICP queries are logged to access.log. You may wish # do disable this if your ICP load is VERY high to speed things # up or to simplify log analysis. # #Default: # log_icp_queries on # TAG: udp_incoming_address # udp_incoming_address is used for UDP packets received from other # caches. # # The default behavior is to not bind to any specific address. # # Only change this if you want to have all UDP queries received on # a specific interface/address. # # NOTE: udp_incoming_address is used by the ICP, HTCP, and DNS # modules. Altering it will affect all of them in the same manner. # # see also; udp_outgoing_address # # NOTE, udp_incoming_address and udp_outgoing_address can not # have the same value since they both use the same port. # #Default: # udp_incoming_address 0.0.0.0 # TAG: udp_outgoing_address # udp_outgoing_address is used for UDP packets sent out to other # caches. # # The default behavior is to not bind to any specific address. # # Instead it will use the same socket as udp_incoming_address. # Only change this if you want to have UDP queries sent using another # address than where this Squid listens for UDP queries from other # caches. # # NOTE: udp_outgoing_address is used by the ICP, HTCP, and DNS # modules. Altering it will affect all of them in the same manner. # # see also; udp_incoming_address # # NOTE, udp_incoming_address and udp_outgoing_address can not # have the same value since they both use the same port. # #Default: # udp_outgoing_address 255.255.255.255 # TAG: icp_hit_stale on|off # If you want to return ICP_HIT for stale cache objects, set this # option to 'on'. If you have sibling relationships with caches # in other administrative domains, this should be 'off'. If you only # have sibling relationships with caches under your control, # it is probably okay to set this to 'on'. # If set to 'on', your siblings should use the option "allow-miss" # on their cache_peer lines for connecting to you. # #Default: # icp_hit_stale off # TAG: minimum_direct_hops # If using the ICMP pinging stuff, do direct fetches for sites # which are no more than this many hops away. # #Default: # minimum_direct_hops 4 # TAG: minimum_direct_rtt # If using the ICMP pinging stuff, do direct fetches for sites # which are no more than this many rtt milliseconds away. # #Default: # minimum_direct_rtt 400 # TAG: netdb_low # TAG: netdb_high # The low and high water marks for the ICMP measurement # database. These are counts, not percents. The defaults are # 900 and 1000. When the high water mark is reached, database # entries will be deleted until the low mark is reached. # #Default: # netdb_low 900 # netdb_high 1000 # TAG: netdb_ping_period # The minimum period for measuring a site. There will be at # least this much delay between successive pings to the same # network. The default is five minutes. # #Default: # netdb_ping_period 5 minutes # TAG: query_icmp on|off # If you want to ask your peers to include ICMP data in their ICP # replies, enable this option. # # If your peer has configured Squid (during compilation) with # '--enable-icmp' that peer will send ICMP pings to origin server # sites of the URLs it receives. If you enable this option the # ICP replies from that peer will include the ICMP data (if available). # Then, when choosing a parent cache, Squid will choose the parent with # the minimal RTT to the origin server. When this happens, the # hierarchy field of the access.log will be # "CLOSEST_PARENT_MISS". This option is off by default. # #Default: # query_icmp off # TAG: test_reachability on|off # When this is 'on', ICP MISS replies will be ICP_MISS_NOFETCH # instead of ICP_MISS if the target host is NOT in the ICMP # database, or has a zero RTT. # #Default: # test_reachability off # TAG: icp_query_timeout (msec) # Normally Squid will automatically determine an optimal ICP # query timeout value based on the round-trip-time of recent ICP # queries. If you want to override the value determined by # Squid, set this 'icp_query_timeout' to a non-zero value. This # value is specified in MILLISECONDS, so, to use a 2-second # timeout (the old default), you would write: # # icp_query_timeout 2000 # #Default: # icp_query_timeout 0 # TAG: maximum_icp_query_timeout (msec) # Normally the ICP query timeout is determined dynamically. But # sometimes it can lead to very large values (say 5 seconds). # Use this option to put an upper limit on the dynamic timeout # value. Do NOT use this option to always use a fixed (instead # of a dynamic) timeout value. To set a fixed timeout see the # 'icp_query_timeout' directive. # #Default: # maximum_icp_query_timeout 2000 # TAG: minimum_icp_query_timeout (msec) # Normally the ICP query timeout is determined dynamically. But # sometimes it can lead to very small timeouts, even lower than # the normal latency variance on your link due to traffic. # Use this option to put an lower limit on the dynamic timeout # value. Do NOT use this option to always use a fixed (instead # of a dynamic) timeout value. To set a fixed timeout see the # 'icp_query_timeout' directive. # #Default: # minimum_icp_query_timeout 5 # MULTICAST ICP OPTIONS # ----------------------------------------------------------------------------- # TAG: mcast_groups # This tag specifies a list of multicast groups which your server # should join to receive multicasted ICP queries. # # NOTE! Be very careful what you put here! Be sure you # understand the difference between an ICP _query_ and an ICP # _reply_. This option is to be set only if you want to RECEIVE # multicast queries. Do NOT set this option to SEND multicast # ICP (use cache_peer for that). ICP replies are always sent via # unicast, so this option does not affect whether or not you will # receive replies from multicast group members. # # You must be very careful to NOT use a multicast address which # is already in use by another group of caches. # # If you are unsure about multicast, please read the Multicast # chapter in the Squid FAQ (http://www.squid-cache.org/FAQ/). # # Usage: mcast_groups 239.128.16.128 224.0.1.20 # # By default, Squid doesn't listen on any multicast groups. # #Default: # none # TAG: mcast_miss_addr # Note: This option is only available if Squid is rebuilt with the # --enable-multicast-miss option # # If you enable this option, every "cache miss" URL will # be sent out on the specified multicast address. # # Do not enable this option unless you are are absolutely # certain you understand what you are doing. # #Default: # mcast_miss_addr 255.255.255.255 # TAG: mcast_miss_ttl # Note: This option is only available if Squid is rebuilt with the # --enable-multicast-miss option # # This is the time-to-live value for packets multicasted # when multicasting off cache miss URLs is enabled. By # default this is set to 'site scope', i.e. 16. # #Default: # mcast_miss_ttl 16 # TAG: mcast_miss_port # Note: This option is only available if Squid is rebuilt with the # --enable-multicast-miss option # # This is the port number to be used in conjunction with # 'mcast_miss_addr'. # #Default: # mcast_miss_port 3135 # TAG: mcast_miss_encode_key # Note: This option is only available if Squid is rebuilt with the # --enable-multicast-miss option # # The URLs that are sent in the multicast miss stream are # encrypted. This is the encryption key. # #Default: # mcast_miss_encode_key XXXXXXXXXXXXXXXX # TAG: mcast_icp_query_timeout (msec) # For multicast peers, Squid regularly sends out ICP "probes" to # count how many other peers are listening on the given multicast # address. This value specifies how long Squid should wait to # count all the replies. The default is 2000 msec, or 2 # seconds. # #Default: # mcast_icp_query_timeout 2000 # INTERNAL ICON OPTIONS # ----------------------------------------------------------------------------- # TAG: icon_directory # Where the icons are stored. These are normally kept in # /usr/share/squid/icons # #Default: # icon_directory /usr/share/squid/icons # TAG: global_internal_static # This directive controls is Squid should intercept all requests for # /squid-internal-static/ no matter which host the URL is requesting # (default on setting), or if nothing special should be done for # such URLs (off setting). The purpose of this directive is to make # icons etc work better in complex cache hierarchies where it may # not always be possible for all corners in the cache mesh to reach # the server generating a directory listing. # #Default: # global_internal_static on # TAG: short_icon_urls # If this is enabled Squid will use short URLs for icons. # # If off the URLs for icons will always be absolute URLs # including the proxy name and port. # #Default: # short_icon_urls off # ERROR PAGE OPTIONS # ----------------------------------------------------------------------------- # TAG: error_directory # If you wish to create your own versions of the default # (English) error files, either to customize them to suit your # language or company copy the template English files to another # directory and point this tag at them. # # The squid developers are interested in making squid available in # a wide variety of languages. If you are making translations for a # langauge that Squid does not currently provide please consider # contributing your translation back to the project. # #Default: # error_directory /usr/share/squid/errors/en # TAG: error_map # Map errors to custom messages # # error_map message_url http_status ... # # http_status ... is a list of HTTP status codes or Squid error # messages. # # Use in accelerators to substitute the error messages returned # by servers with other custom errors. # # error_map http://your.server/error/404.shtml 404 # # Requests for error messages is a GET request for the configured # URL with the following special headers # # X-Error-Status: The received HTTP status code (i.e. 404) # X-Request-URI: The requested URI where the error occurred # # In Addition the following headers are forwarded from the client # request: # # User-Agent, Cookie, X-Forwarded-For, Via, Authorization, # Accept, Referer # # And the following headers from the server reply: # # Server, Via, Location, Content-Location # # The reply returned to the client will carry the original HTTP # headers from the real error message, but with the reply body # of the configured error message. # # #Default: # none # TAG: err_html_text # HTML text to include in error messages. Make this a "mailto" # URL to your admin address, or maybe just a link to your # organizations Web page. # # To include this in your error messages, you must rewrite # the error template files (found in the "errors" directory). # Wherever you want the 'err_html_text' line to appear, # insert a %L tag in the error template file. # #Default: # none # TAG: deny_info # Usage: deny_info err_page_name acl # or deny_info http://... acl # Example: deny_info ERR_CUSTOM_ACCESS_DENIED bad_guys # # This can be used to return a ERR_ page for requests which # do not pass the 'http_access' rules. Squid remembers the last # acl it evaluated in http_access, and if a 'deny_info' line exists # for that ACL Squid returns a corresponding error page. # # The acl is typically the last acl on the http_access deny line which # denied access. The exceptions to this rule are: # - When Squid needs to request authentication credentials. It's then # the first authentication related acl encountered # - When none of the http_access lines matches. It's then the last # acl processed on the last http_access line. # # You may use ERR_ pages that come with Squid or create your own pages # and put them into the configured errors/ directory. # # Alternatively you can specify an error URL. The browsers will # get redirected (302) to the specified URL. %s in the redirection # URL will be replaced by the requested URL. # # Alternatively you can tell Squid to reset the TCP connection # by specifying TCP_RESET. # #Default: # none # OPTIONS INFLUENCING REQUEST FORWARDING # ----------------------------------------------------------------------------- # TAG: nonhierarchical_direct # By default, Squid will send any non-hierarchical requests # (matching hierarchy_stoplist or not cacheable request type) direct # to origin servers. # # If you set this to off, Squid will prefer to send these # requests to parents. # # Note that in most configurations, by turning this off you will only # add latency to these request without any improvement in global hit # ratio. # # If you are inside an firewall see never_direct instead of # this directive. # #Default: # nonhierarchical_direct on # TAG: prefer_direct # Normally Squid tries to use parents for most requests. If you for some # reason like it to first try going direct and only use a parent if # going direct fails set this to on. # # By combining nonhierarchical_direct off and prefer_direct on you # can set up Squid to use a parent as a backup path if going direct # fails. # # Note: If you want Squid to use parents for all requests see # the never_direct directive. prefer_direct only modifies how Squid # acts on cacheable requests. # #Default: # prefer_direct off # TAG: ignore_ims_on_miss on|off # This options makes Squid ignore If-Modified-Since on # cache misses. This is useful while the cache is # mostly empty to more quickly have the cache populated. # #Default: # ignore_ims_on_miss off # TAG: always_direct # Usage: always_direct allow|deny [!]aclname ... # # Here you can use ACL elements to specify requests which should # ALWAYS be forwarded by Squid to the origin servers without using # any peers. For example, to always directly forward requests for # local servers ignoring any parents or siblings you may have use # something like: # # acl local-servers dstdomain my.domain.net # always_direct allow local-servers # # To always forward FTP requests directly, use # # acl FTP proto FTP # always_direct allow FTP # # NOTE: There is a similar, but opposite option named # 'never_direct'. You need to be aware that "always_direct deny # foo" is NOT the same thing as "never_direct allow foo". You # may need to use a deny rule to exclude a more-specific case of # some other rule. Example: # # acl local-external dstdomain external.foo.net # acl local-servers dstdomain .foo.net # always_direct deny local-external # always_direct allow local-servers # # NOTE: If your goal is to make the client forward the request # directly to the origin server bypassing Squid then this needs # to be done in the client configuration. Squid configuration # can only tell Squid how Squid should fetch the object. # # NOTE: This directive is not related to caching. The replies # is cached as usual even if you use always_direct. To not cache # the replies see no_cache. # # This option replaces some v1.1 options such as local_domain # and local_ip. # #Default: # none # TAG: never_direct # Usage: never_direct allow|deny [!]aclname ... # # never_direct is the opposite of always_direct. Please read # the description for always_direct if you have not already. # # With 'never_direct' you can use ACL elements to specify # requests which should NEVER be forwarded directly to origin # servers. For example, to force the use of a proxy for all # requests, except those in your local domain use something like: # # acl local-servers dstdomain .foo.net # acl all src 0.0.0.0/0.0.0.0 # never_direct deny local-servers # never_direct allow all # # or if Squid is inside a firewall and there are local intranet # servers inside the firewall use something like: # # acl local-intranet dstdomain .foo.net # acl local-external dstdomain external.foo.net # always_direct deny local-external # always_direct allow local-intranet # never_direct allow all # # This option replaces some v1.1 options such as inside_firewall # and firewall_ip. # #Default: # none # ADVANCED NETWORKING OPTIONS # ----------------------------------------------------------------------------- # TAG: max_filedescriptors # The maximum number of filedescriptors supported. # # The default "0" means Squid inherits the current ulimit setting. # # Note: Changing this requires a restart of Squid. Also # not all comm loops supports values larger than --with-maxfd. # #Default: # max_filedescriptors 0 # TAG: accept_filter # FreeBSD: # # The name of an accept(2) filter to install on Squid's # listen socket(s). This feature is perhaps specific to # FreeBSD and requires support in the kernel. # # The 'httpready' filter delays delivering new connections # to Squid until a full HTTP request has been received. # See the accf_http(9) man page for details. # # The 'dataready' filter delays delivering new connections # to Squid until there is some data to process. # See the accf_dataready(9) man page for details. # # Linux: # # The 'data' filter delays delivering of new connections # to Squid until there is some data to process by TCP_ACCEPT_DEFER. # You may optionally specify a number of seconds to wait by # 'data=N' where N is the number of seconds. Defaults to 30 # if not specified. See the tcp(7) man page for details. #EXAMPLE: ## FreeBSD #accept_filter httpready ## Linux #accept_filter data # #Default: # none # TAG: tcp_recv_bufsize (bytes) # Size of receive buffer to set for TCP sockets. Probably just # as easy to change your kernel's default. Set to zero to use # the default buffer size. # #Default: # tcp_recv_bufsize 0 bytes # TAG: incoming_rate # This directive controls how aggressive Squid should accept new # connections compared to processing existing connections. # The lower number the more frequent Squid will look for new # incoming requests. # #Default: # incoming_rate 30 # DNS OPTIONS # ----------------------------------------------------------------------------- # TAG: check_hostnames # For security and stability reasons Squid by default checks # hostnames for Internet standard RFC compliance. If you do not want # Squid to perform these checks then turn this directive off. # #Default: # check_hostnames on # TAG: allow_underscore # Underscore characters is not strictly allowed in Internet hostnames # but nevertheless used by many sites. Set this to off if you want # Squid to be strict about the standard. # This check is performed only when check_hostnames is set to on. # #Default: # allow_underscore on # TAG: cache_dns_program # Note: This option is only available if Squid is rebuilt with the # --disable-internal-dns option # # Specify the location of the executable for dnslookup process. # #Default: # cache_dns_program /usr/lib/squid/dnsserver # TAG: dns_children # Note: This option is only available if Squid is rebuilt with the # --disable-internal-dns option # # The number of processes spawn to service DNS name lookups. # For heavily loaded caches on large servers, you should # probably increase this value to at least 10. The maximum # is 32. The default is 5. # # You must have at least one dnsserver process. # #Default: # dns_children 5 # TAG: dns_retransmit_interval # Initial retransmit interval for DNS queries. The interval is # doubled each time all configured DNS servers have been tried. # # #Default: # dns_retransmit_interval 5 seconds # TAG: dns_timeout # DNS Query timeout. If no response is received to a DNS query # within this time all DNS servers for the queried domain # are assumed to be unavailable. # #Default: # dns_timeout 2 minutes # TAG: dns_defnames on|off # Normally the RES_DEFNAMES resolver option is disabled # (see res_init(3)). This prevents caches in a hierarchy # from interpreting single-component hostnames locally. To allow # Squid to handle single-component names, enable this option. # #Default: # dns_defnames off # TAG: dns_nameservers # Use this if you want to specify a list of DNS name servers # (IP addresses) to use instead of those given in your # /etc/resolv.conf file. # On Windows platforms, if no value is specified here or in # the /etc/resolv.conf file, the list of DNS name servers are # taken from the Windows registry, both static and dynamic DHCP # configurations are supported. # # Example: dns_nameservers 10.0.0.1 192.172.0.4 # #Default: # none # TAG: hosts_file # Location of the host-local IP name-address associations # database. Most Operating Systems have such a file on different # default locations: # - Un*X & Linux: /etc/hosts # - Windows NT/2000: %SystemRoot%\system32\drivers\etc\hosts # (%SystemRoot% value install default is c:\winnt) # - Windows XP/2003: %SystemRoot%\system32\drivers\etc\hosts # (%SystemRoot% value install default is c:\windows) # - Windows 9x/Me: %windir%\hosts # (%windir% value is usually c:\windows) # - Cygwin: /etc/hosts # # The file contains newline-separated definitions, in the # form ip_address_in_dotted_form name [name ...] names are # whitespace-separated. Lines beginning with an hash (#) # character are comments. # # The file is checked at startup and upon configuration. # If set to 'none', it won't be checked. # If append_domain is used, that domain will be added to # domain-local (i.e. not containing any dot character) host # definitions. # #Default: # hosts_file /etc/hosts # hosts_file /etc/hosts # TAG: dns_testnames # The DNS tests exit as soon as the first site is successfully looked up # # This test can be disabled with the -D command line option. # #Default: # dns_testnames netscape.com internic.net nlanr.net microsoft.com # TAG: append_domain # Appends local domain name to hostnames without any dots in # them. append_domain must begin with a period. # # Be warned there are now Internet names with no dots in # them using only top-domain names, so setting this may # cause some Internet sites to become unavailable. # #Example: # append_domain .yourdomain.com # #Default: # none # TAG: ignore_unknown_nameservers # By default Squid checks that DNS responses are received # from the same IP addresses they are sent to. If they # don't match, Squid ignores the response and writes a warning # message to cache.log. You can allow responses from unknown # nameservers by setting this option to 'off'. # #Default: # ignore_unknown_nameservers on # TAG: ipcache_size (number of entries) # TAG: ipcache_low (percent) # TAG: ipcache_high (percent) # The size, low-, and high-water marks for the IP cache. # #Default: # ipcache_size 1024 # ipcache_low 90 # ipcache_high 95 # TAG: fqdncache_size (number of entries) # Maximum number of FQDN cache entries. # #Default: # fqdncache_size 1024 # MISCELLANEOUS # ----------------------------------------------------------------------------- # TAG: memory_pools on|off # If set, Squid will keep pools of allocated (but unused) memory # available for future use. If memory is a premium on your # system and you believe your malloc library outperforms Squid # routines, disable this. # #Default: # memory_pools on # TAG: memory_pools_limit (bytes) # Used only with memory_pools on: # memory_pools_limit 50 MB # # If set to a non-zero value, Squid will keep at most the specified # limit of allocated (but unused) memory in memory pools. All free() # requests that exceed this limit will be handled by your malloc # library. Squid does not pre-allocate any memory, just safe-keeps # objects that otherwise would be free()d. Thus, it is safe to set # memory_pools_limit to a reasonably high value even if your # configuration will use less memory. # # If set to zero, Squid will keep all memory it can. That is, there # will be no limit on the total amount of memory used for safe-keeping. # # To disable memory allocation optimization, do not set # memory_pools_limit to 0. Set memory_pools to "off" instead. # # An overhead for maintaining memory pools is not taken into account # when the limit is checked. This overhead is close to four bytes per # object kept. However, pools may actually _save_ memory because of # reduced memory thrashing in your malloc library. # #Default: # memory_pools_limit 5 MB # TAG: forwarded_for on|off # If set, Squid will include your system's IP address or name # in the HTTP requests it forwards. By default it looks like # this: # # X-Forwarded-For: 192.1.2.3 # # If you disable this, it will appear as # # X-Forwarded-For: unknown # #Default: # forwarded_for on # TAG: cachemgr_passwd # Specify passwords for cachemgr operations. # # Usage: cachemgr_passwd password action action ... # # Some valid actions are (see cache manager menu for a full list): # 5min # 60min # asndb # authenticator # cbdata # client_list # comm_incoming # config * # counters # delay # digest_stats # dns # events # filedescriptors # fqdncache # histograms # http_headers # info # io # ipcache # mem # menu # netdb # non_peers # objects # offline_toggle * # pconn # peer_select # reconfigure * # redirector # refresh # server_list # shutdown * # store_digest # storedir # utilization # via_headers # vm_objects # # * Indicates actions which will not be performed without a # valid password, others can be performed if not listed here. # # To disable an action, set the password to "disable". # To allow performing an action without a password, set the # password to "none". # # Use the keyword "all" to set the same password for all actions. # #Example: # cachemgr_passwd secret shutdown # cachemgr_passwd lesssssssecret info stats/objects # cachemgr_passwd disable all # #Default: # none # TAG: client_db on|off # If you want to disable collecting per-client statistics, # turn off client_db here. # #Default: # client_db on # TAG: reload_into_ims on|off # When you enable this option, client no-cache or ``reload'' # requests will be changed to If-Modified-Since requests. # Doing this VIOLATES the HTTP standard. Enabling this # feature could make you liable for problems which it # causes. # # see also refresh_pattern for a more selective approach. # #Default: # reload_into_ims off # TAG: maximum_single_addr_tries # This sets the maximum number of connection attempts for a # host that only has one address (for multiple-address hosts, # each address is tried once). # # The default value is one attempt, the (not recommended) # maximum is 255 tries. A warning message will be generated # if it is set to a value greater than ten. # # Note: This is in addition to the request re-forwarding which # takes place if Squid fails to get a satisfying response. # #Default: # maximum_single_addr_tries 1 # TAG: retry_on_error # If set to on Squid will automatically retry requests when # receiving an error response. This is mainly useful if you # are in a complex cache hierarchy to work around access # control errors. # #Default: # retry_on_error off # TAG: as_whois_server # WHOIS server to query for AS numbers. NOTE: AS numbers are # queried only when Squid starts up, not for every request. # #Default: # as_whois_server whois.ra.net # as_whois_server whois.ra.net # TAG: offline_mode # Enable this option and Squid will never try to validate cached # objects. # #Default: # offline_mode off # TAG: uri_whitespace # What to do with requests that have whitespace characters in the # URI. Options: # # strip: The whitespace characters are stripped out of the URL. # This is the behavior recommended by RFC2396. # deny: The request is denied. The user receives an "Invalid # Request" message. # allow: The request is allowed and the URI is not changed. The # whitespace characters remain in the URI. Note the # whitespace is passed to redirector processes if they # are in use. # encode: The request is allowed and the whitespace characters are # encoded according to RFC1738. This could be considered # a violation of the HTTP/1.1 # RFC because proxies are not allowed to rewrite URI's. # chop: The request is allowed and the URI is chopped at the # first whitespace. This might also be considered a # violation. # #Default: # uri_whitespace strip # TAG: coredump_dir # By default Squid leaves core files in the directory from where # it was started. If you set 'coredump_dir' to a directory # that exists, Squid will chdir() to that directory at startup # and coredump files will be left there. # #Default: # coredump_dir none # # Leave coredumps in the first cache dir coredump_dir /var/spool/squid # TAG: chroot # Use this to have Squid do a chroot() while initializing. This # also causes Squid to fully drop root privileges after # initializing. This means, for example, if you use a HTTP # port less than 1024 and try to reconfigure, you will may get an # error saying that Squid can not open the port. # #Default: # none # TAG: balance_on_multiple_ip # Some load balancing servers based on round robin DNS have been # found not to preserve user session state across requests # to different IP addresses. # # By default Squid rotates IP's per request. By disabling # this directive only connection failure triggers rotation. # #Default: # balance_on_multiple_ip on # TAG: pipeline_prefetch # To boost the performance of pipelined requests to closer # match that of a non-proxied environment Squid can try to fetch # up to two requests in parallel from a pipeline. # # Defaults to off for bandwidth management and access logging # reasons. # #Default: # pipeline_prefetch off # TAG: high_response_time_warning (msec) # If the one-minute median response time exceeds this value, # Squid prints a WARNING with debug level 0 to get the # administrators attention. The value is in milliseconds. # #Default: # high_response_time_warning 0 # TAG: high_page_fault_warning # If the one-minute average page fault rate exceeds this # value, Squid prints a WARNING with debug level 0 to get # the administrators attention. The value is in page faults # per second. # #Default: # high_page_fault_warning 0 # TAG: high_memory_warning # If the memory usage (as determined by mallinfo) exceeds # this amount, Squid prints a WARNING with debug level 0 to get # the administrators attention. # #Default: # high_memory_warning 0 KB # TAG: sleep_after_fork (microseconds) # When this is set to a non-zero value, the main Squid process # sleeps the specified number of microseconds after a fork() # system call. This sleep may help the situation where your # system reports fork() failures due to lack of (virtual) # memory. Note, however, if you have a lot of child # processes, these sleep delays will add up and your # Squid will not service requests for some amount of time # until all the child processes have been started. # On Windows value less then 1000 (1 milliseconds) are # rounded to 1000. # #Default: # sleep_after_fork 0 # TAG: zero_buffers on|off # Squid by default will zero all buffers before using or reusing them. # Setting this to 'off' will result in fixed-sized temporary buffers # not being zero'ed. This may give a performance boost on certain # platforms but it may result in undefined behaviour at the present # time. # #Default: # zero_buffers on # TAG: windows_ipaddrchangemonitor on|off # On Windows Squid by default will monitor IP address changes and will # reconfigure itself after any detected event. This is very useful for # proxies connected to internet with dial-up interfaces. # In some cases (a Proxy server acting as VPN gateway is one) it could be # desiderable to disable this behaviour setting this to 'off'. # Note: after changing this, Squid service must be restarted. # #Default: # windows_ipaddrchangemonitor on