Common configuration topicsDo not enable proxying with ProxyRequests until you have secured your server. Open proxy servers are dangerous both to your
+ network and to the Internet at large.
This module implements a proxy/gateway for Apache. It implements
-proxying capability for
-FTP,
-CONNECT (for SSL),
-HTTP/0.9,
-HTTP/1.0, and
-HTTP/1.1.
-The module can be configured to connect to other proxy modules for these
-and other protocols.
This module implements a proxy/gateway for Apache. It implements
+ proxying capability for FTP, CONNECT (for SSL),
+ HTTP/0.9, HTTP/1.0, and HTTP/1.1.
+ The module can be configured to connect to other proxy modules for these
+ and other protocols.
This module was experimental in Apache 1.1.x. Improvements and bugfixes -were made in Apache v1.2.x and Apache v1.3.x, then the module underwent a major -overhaul for Apache v2.0. The protocol support was upgraded to HTTP/1.1, -and filter support was enabled.
+This module was experimental in Apache 1.1.x. Improvements and bugfixes
+ were made in Apache v1.2.x and Apache v1.3.x, then the module underwent a
+ major overhaul for Apache v2.0. The protocol support was upgraded to
+ HTTP/1.1, and filter support was enabled.
Please note that the caching function present in -mod_proxy up to Apache v1.3.x has been removed from -mod_proxy and will be incorporated into a new module, mod_cache. In other words: -the Apache 2.0.x-Proxy doesn't -cache at all - all caching functionality has been moved into mod_cache, -which is capable of caching any content, not only content from proxy. -
- -If you need to use SSL when contacting remote servers, have a look at the
-SSLProxy* directives in mod_ssl.
Do not enable proxying with ProxyRequests until you have
-secured your server. Open proxy servers are
-dangerous both to your network and to the Internet at large.
During the overhaul process the mod_proxy has been
+ splitted into several module files. The accompanying modules distributed
+ with the httpd are mod_proxy_http,
+ mod_proxy_ftp and mod_proxy_connect.
+ Thus if you want to use one or more of the particular proxy functions you
+ have to load mod_proxy and the appropriate
+ module(s) into the server (either statically or dynamically via the
+ LoadModule directive).
Please note that the caching function present in mod_proxy up to Apache v1.3.x has been removed
+ from mod_proxy and will be incorporated into a new module,
+ mod_cache. In other words: the Apache 2.0.x-Proxy doesn't
+ cache at all - all caching functionality has been moved into
+ mod_cache, which is capable of caching any content, not
+ only content from proxy.
If you need to use SSL when contacting remote servers, have a look at the
+ SSLProxy* directives in mod_ssl.
Apache can be configured in both a forward and + reverse proxy configuration.
-A forward proxy is an intermediate system that enables a + browser to connect to a remote network to which it normally does not have + access. A forward proxy can also be used to cache data, reducing load on + the networks between the forward proxy and the remote webserver.
-Apache's mod_proxy can be figured to behave like a
+ forward proxy using the ProxyRemote directive. In addition, caching of data can be
+ achieved by configuring mod_cache. Other dedicated
+ forward proxy packages include Squid.
Apache can be configured in both a forward and reverse -proxy configuration.
+A reverse proxy is a webserver system that is capable of + serving webpages sourced from other webservers - in addition to webpages + on disk or generated dynamically by CGI - making these pages look like + they originated at the reverse proxy.
-A forward proxy is an intermediate system that enables a browser to connect to a -remote network to which it normally does not have access. A forward proxy -can also be used to cache data, reducing load on the networks between the -forward proxy and the remote webserver.
+When configured with the mod_cache module the reverse proxy can act as
+ a cache for slower backend webservers. The reverse proxy can also enable
+ advanced URL strategies and management techniques, allowing webpages
+ served using different webserver systems or architectures to coexist
+ inside the same URL space. Reverse proxy systems are also ideal for
+ implementing centralised logging websites with many or diverse website
+ backends. Complex multi-tier webserver systems can be constructed using an
+ mod_proxy frontend and any number of backend
+ webservers.
Apache's mod_proxy can be figured to behave like a forward proxy
-using the ProxyRemote
-directive. In addition, caching of data can be achieved by configuring
-Apache mod_cache. Other dedicated forward proxy
-packages include Squid.
The reverse proxy is configured using the ProxyPass and ProxyPassReverse directives. Caching can be
+ enabled using mod_cache as with the forward proxy.
A reverse proxy is a webserver system that is capable of serving webpages -sourced from other webservers - in addition to webpages on disk or generated -dynamically by CGI - making these pages look like they originated at the -reverse proxy.
+You can control who can access your proxy via the <Proxy> control block using
+ the following example:
When configured with the mod_cache module the reverse -proxy can act as a cache for slower backend webservers. The reverse proxy -can also enable advanced URL strategies and management techniques, allowing -webpages served using different webserver systems or architectures to -coexist inside the same URL space. Reverse proxy systems are also ideal for -implementing centralised logging websites with many or diverse website -backends. Complex multi-tier webserver systems can be constructed using an -Apache mod_proxy frontend and any number of backend webservers.
+
+ <Proxy *>
+
+ Order Deny,Allow
+ Deny from all
+ Allow from 192.168.0
+
+ </Proxy>
+
The reverse proxy is configured using the
-ProxyPass and ProxyPassReverse directives. Caching can be
-enabled using mod_cache as with the forward proxy.
When configuring a reverse proxy, access control takes on the
+ attributes of the normal server <Directory> configuration.
You probably don't have that particular file type defined as
+ application/octet-stream in your proxy's mime.types
+ configuration file. A useful line can be
application/octet-stream bin dms lha lzh exe class tgz taz
In the rare situation where you must download a specific file using the
+ FTP ASCII transfer method (while the default transfer is in
+ binary mode), you can override mod_proxy's
+ default by suffixing the request with ;type=a to force an
+ ASCII transfer. (FTP Directory listings are always executed in ASCII mode,
+ however.)
You can control who can access your proxy via the
-<Proxy>
-control block using the following example:
An FTP URI is interpreted relative to the home directory of the user
+ who is logging in. Alas, to reach higher directory levels you cannot
+ use /../, as the dots are interpreted by the browser and not actually
+ sent to the FTP server. To address this problem, the so called Squid
+ %2f hack was implemented in the Apache FTP proxy; it is a
+ solution which is also used by other popular proxy servers like the Squid Proxy Cache. By
+ prepending /%2f to the path of your request, you can make
+ such a proxy change the FTP starting directory to / (instead
+ of the home directory). For example, to retrieve the file
+ /etc/motd, you would use the URL:
-<Proxy *>
-Order Deny,Allow
-Deny from all
-Allow from 192.168.0
-</Proxy>
-
+ ftp://user@host/%2f/etc/motd
+
When configuring a reverse proxy, access control takes on the
-attributes of the normal server <directory> configuration.
To log in to an FTP server by username and password, Apache uses + different strategies. In absense of a user name and password in the URL + altogether, Apache sends an anomymous login to the FTP server, + i.e.,
+
+ user: anonymous
+ password: apache_proxy@
+
This works for all popular FTP servers which are configured for + anonymous access.
-You probably don't have that particular file type defined as -application/octet-stream in your proxy's mime.types configuration -file. A useful line can be
+For a personal login with a specific username, you can embed the user + name into the URL, like in:
-
-application/octet-stream bin dms lha lzh exe class tgz taz
-
+ ftp://username@host/myfile
+
If the FTP server asks for a password when given this username (which
+ it should), then Apache will reply with a 401 (Authorization
+ required) response, which causes the Browser to pop up the
+ username/password dialog. Upon entering the password, the connection
+ attempt is retried, and if successful, the requested resource is
+ presented. The advantage of this procedure is that your browser does not
+ display the password in cleartext (which it would if you had used
+ ftp://username:password@host/myfile
+
In the rare situation where you must download a specific file using the FTP
-ASCII transfer method (while the default transfer is in
-binary mode), you can override mod_proxy's default by
-suffixing the request with ;type=a to force an ASCII transfer.
-(FTP Directory listings are always executed in ASCII mode, however.)
in the first place).
+The password which is transmitted in such a way is not encrypted on + its way. It travels between your browser and the Apache proxy server in + a base64-encoded cleartext string, and between the Apache proxy and the + FTP server as plaintext. You should therefore think twice before + accessing your FTP server via HTTP (or before accessing your personal + files via FTP at all!) When using unsecure channels, an eavesdropper + might intercept your password on its way.
+If you're using the ProxyBlock directive, hostnames' IP addresses are looked up
+ and cached during startup for later match test. This may take a few
+ seconds (or more) depending on the speed with which the hostname lookups
+ occur.
-An FTP URI is interpreted relative to the home directory of the user -who is logging in. Alas, to reach higher directory levels you cannot -use /../, as the dots are interpreted by the browser and not actually -sent to the FTP server. To address this problem, the so called "Squid -%2f hack" was implemented in the Apache FTP proxy; it is is a solution -which is also used by other popular proxy servers like the Squid Proxy Cache. By -prepending /%2f to the path of your request, you can make such a proxy -change the FTP starting directory to / (instead of the home -directory).
+An Apache proxy server situated in an intranet needs to forward
+ external requests through the company's firewall. However, when it has to
+ access resources within the intranet, it can bypass the firewall when
+ accessing hosts. The NoProxy
+ directive is useful for specifying which hosts belong to the intranet and
+ should be accessed directly.
Example: To retrieve the file
-/etc/motd, you would use the URL
ftp://user@host/%2f/etc/motd
-To log in to an FTP server by username and password, Apache -uses different strategies. -In absense of a user name and password in the URL altogether, -Apache sends an anomymous login to the FTP server, i.e.,
-
-user: anonymous
-password: apache_proxy@
-
This works for all popular FTP servers which are configured for -anonymous access.
- -For a personal login with a specific username, you can embed
-the user name into the URL, like in:
-ftp://username@host/myfile. If the FTP server
-asks for a password when given this username (which it should),
-then Apache will reply with a [401 Authorization required] response,
-which causes the Browser to pop up the username/password dialog.
-Upon entering the password, the connection attempt is retried,
-and if successful, the requested resource is presented.
-The advantage of this procedure is that your browser does not
-display the password in cleartext (which it would if you had used
-ftp://username:password@host/myfile in
-the first place).
If you're using the ProxyBlock
-directive, hostnames' IP addresses are looked up and cached during
-startup for later match test. This may take a few seconds (or more)
-depending on the speed with which the hostname lookups occur.
An Apache proxy server situated in an intranet needs to forward
-external requests through the company's firewall. However, when it has
-to access resources within the intranet, it can bypass the firewall
-when accessing hosts. The NoProxy directive is useful for
-specifying which hosts belong to the intranet and should be accessed
-directly.
Users within an intranet tend to omit the local domain name from their
-WWW requests, thus requesting "http://somehost/" instead of
-"http://somehost.my.dom.ain/". Some commercial proxy servers let them get
-away with this and simply serve the request, implying a configured
-local domain. When the ProxyDomain directive
-is used and the server is configured for
-proxy service, Apache can return a redirect response and send the client
-to the correct, fully qualified, server address. This is the preferred method
-since the user's bookmark files will then contain fully qualified hosts.
For circumstances where you have a application server which doesn't implement
-keepalives or HTTP/1.1 properly, there are 2 environment variables which when
-set send a HTTP/1.0 with no keepalive. These are set via the SetEnv directive.
These are the 'force-proxy-request-1.0' and 'proxy-nokeepalive' notes.
- -
-<location /buggyappserver/ >
-ProxyPass http://buggyappserver:7001/foo/
-SetEnv force-proxy-request-1.0 1
-SetEnv proxy-nokeepalive 1
-</location>
-
Users within an intranet tend to omit the local domain name from their
+ WWW requests, thus requesting "http://somehost/" instead of
+ http://somehost.example.com/. Some commercial proxy servers
+ let them get away with this and simply serve the request, implying a
+ configured local domain. When the ProxyDomain directive is used and the server is configured for proxy service, Apache can return
+ a redirect response and send the client to the correct, fully qualified,
+ server address. This is the preferred method since the user's bookmark
+ files will then contain fully qualified hosts.
For circumstances where you have a application server which doesn't
+ implement keepalives or HTTP/1.1 properly, there are 2 environment
+ variables which when set send a HTTP/1.0 with no keepalive. These are set
+ via the SetEnv directive.
These are the force-proxy-request-1.0 and
+ proxy-nokeepalive notes.
+ <Location /buggyappserver/>
+
+ ProxyPass http://buggyappserver:7001/foo/
+ SetEnv force-proxy-request-1.0 1
+ SetEnv proxy-nokeepalive 1
+
+ </Location>
+
| Description: | Ports that are allowed to CONNECT through -the proxy |
|---|---|
| Syntax: | AllowCONNECT port [port] ... |
| Description: | Ports that are allowed to CONNECT through the +proxy |
| Syntax: | AllowCONNECT port [port] ... |
| Default: | AllowCONNECT 443 563 |
| Context: | server config, virtual host |
| Status: | Extension |
| Module: | mod_proxy |
The AllowCONNECT directive specifies a list
-of port numbers to which the proxy CONNECT method may
-connect. Today's browsers use this method when a https
-connection is requested and proxy tunneling over http is in
-effect.
By default, only the default https port (443) and the
-default snews port (563) are enabled. Use the
-AllowCONNECT directive to overrride this default and
-allow connections to the listed ports only.
The AllowCONNECT directive specifies a list
+ of port numbers to which the proxy CONNECT method may
+ connect. Today's browsers use this method when a https
+ connection is requested and proxy tunneling over HTTP is in effect.
By default, only the default https port (443) and the
+ default snews port (563) are enabled. Use the
+ AllowCONNECT directive to override this default and
+ allow connections to the listed ports only.
Note that you'll need to have mod_proxy_connect present
+ in the server in order to get the support for the CONNECT at
+ all.
| Description: | Hosts, domains, or networks that will be connected -to directly |
|---|---|
| Syntax: | NoProxy host [host] ... |
| Description: | Hosts, domains, or networks that will be connected to +directly |
| Syntax: | NoProxy host [host] ... |
| Context: | server config, virtual host |
| Status: | Extension |
| Module: | mod_proxy |
This directive is only useful for Apache proxy servers within
-intranets. The NoProxy directive specifies a
-list of subnets, IP addresses, hosts and/or domains, separated by
-spaces. A request to a host which matches one or more of these is
-always served directly, without forwarding to the configured
-ProxyRemote proxy server(s).
This directive is only useful for Apache proxy servers within
+ intranets. The NoProxy directive specifies a
+ list of subnets, IP addresses, hosts and/or domains, separated by
+ spaces. A request to a host which matches one or more of these is
+ always served directly, without forwarding to the configured
+ ProxyRemote proxy server(s).
- ProxyRemote * http://firewall.mycompany.com:81
- NoProxy .mycompany.com 192.168.112.0/21
-
+ ProxyRemote * http://firewall.mycompany.com:81
+ NoProxy .mycompany.com 192.168.112.0/21
+
The host arguments to the NoProxy directive are one of the -following type list:
-The host arguments to the NoProxy
+ directive are one of the following type list:
.com .apache.org..MyDomain.com and
- .mydomain.com. (note the trailing period) are
- considered equal. Since a domain comparison does not involve a DNS
- lookup, it is much more efficient than subnet comparison.A Domain is a partially qualified DNS domain name, preceded + by a period. It represents a list of hosts which logically belong to the + same DNS domain or zone (i.e., the suffixes of the hostnames are + all ending in Domain).
+ +
+ .com .apache.org.
+
To distinguish Domains from Hostnames (both syntactically and semantically; a DNS domain can + have a DNS A record, too!), Domains are always written with a + leading period.
+ +Domain name comparisons are done without regard to the case, and
+ Domains are always assumed to be anchored in the root of the
+ DNS tree, therefore two domains .MyDomain.com and
+ .mydomain.com. (note the trailing period) are considered
+ equal. Since a domain comparison does not involve a DNS lookup, it is much
+ more efficient than subnet comparison.
192.168 or 192.168.0.0255.255.0.0)192.168.112.0/21192.168.112.0/21 with a netmask of 21
- valid bits (also used in the form 255.255.248.0)A SubNet is a partially qualified internet address in + numeric (dotted quad) form, optionally followed by a slash and the netmask, + specified as the number of significant bits in the SubNet. It is + used to represent a subnet of hosts which can be reached over a common + network interface. In the absence of the explicit net mask it is assumed + that omitted (or zero valued) trailing digits specify the mask. (In this + case, the netmask can only be multiples of 8 bits wide.) Examples:
+ +192.168 or 192.168.0.0255.255.0.0)192.168.112.0/21192.168.112.0/21 with a netmask of 21
+ valid bits (also used in the form 255.255.248.0)As a degenerate case, a SubNet with 32 valid bits is the + equivalent to an IPAddr, while a SubNet with zero + valid bits (e.g., 0.0.0.0/0) is the same as the constant + _Default_, matching any IP address.
A IPAddr represents a fully qualified internet address in + numeric (dotted quad) form. Usually, this address represents a host, but + there need not necessarily be a DNS domain name connected with the + address.
+
+ 192.168.123.7
+
An IPAddr does not need to be resolved by the DNS system, so + it can result in more effective apache performance.
+prep.ai.mit.edu
- www.apache.org.WWW.MyDomain.com
- and www.mydomain.com. (note the trailing period) are
- considered equal.A Hostname is a fully qualified DNS domain name which can + be resolved to one or more IPAddrs via the + DNS domain name service. It represents a logical host (in contrast to + Domains, see above) and must be resolvable + to at least one IPAddr (or often to a list + of hosts with different IPAddrs).
+ +
+ prep.ai.mit.edu
+ www.apache.org
+
In many situations, it is more effective to specify an IPAddr in place of a Hostname since a + DNS lookup can be avoided. Name resolution in Apache can take a remarkable + deal of time when the connection to the name server uses a slow PPP + link.
+Hostname comparisons are done without regard to the case,
+ and Hostnames are always assumed to be anchored in the root
+ of the DNS tree, therefore two hosts WWW.MyDomain.com
+ and www.mydomain.com. (note the trailing period) are
+ considered equal.
| Description: | Container for directives applied to proxied -resources |
|---|---|
| Syntax: | <Proxy wildcard-url> ...</Proxy> |
| Description: | Container for directives applied to proxied resources |
| Syntax: | <Proxy wildcard-url> ...</Proxy> |
| Context: | server config, virtual host |
| Status: | Extension |
| Module: | mod_proxy |
Directives placed in <Proxy>
-sections apply only to matching proxied content. Shell-style
-wildcards are allowed.
Directives placed in <Proxy>
+ sections apply only to matching proxied content. Shell-style wildcards are
+ allowed.
For example, the following will allow only hosts in
-yournetwork.example.com to access content via your
-proxy server:
For example, the following will allow only hosts in
+ yournetwork.example.com to access content via your proxy
+ server:
-<Proxy *>
- Order Deny,Allow
- Deny from all
- Allow from yournetwork.example.com
-</Proxy>
-
+ <Proxy *>
+
+ Order Deny,Allow
+ Deny from all
+ Allow from yournetwork.example.com
+
+ </Proxy>
+
The following example will process all files in the
-foo directory of example.com through the
-INCLUDES filter when they are sent through the proxy
-server:
-<Proxy http://example.com/foo/*>
- SetOutputFilter INCLUDES
-</Proxy>
-
The following example will process all files in the foo
+ directory of example.com through the INCLUDES
+ filter when they are sent through the proxy server:
+ <Proxy http://example.com/foo/*>
+
+ SetOutputFilter INCLUDES
+
+ </Proxy>
+
The ProxyBadHeader directive determines the behaviour
-of mod_proxy if it receives syntactically invalid header lines
-(i.e. containing no colon). The following arguments are possible:
IsErrorThe ProxyBadHeader directive determines the
+ behaviour of mod_proxy if it receives syntactically invalid
+ header lines (i.e. containing no colon). The following arguments
+ are possible:
IgnoreIsErrorStartBodyIgnoreStartBody| Description: | Words, hosts, or domains that are banned from being proxied |
|---|---|
| Syntax: | ProxyBlock *|word|host|domain
-[word|host|domain] ... |
| Syntax: | ProxyBlock *|word|host|domain
+[word|host|domain] ... |
| Context: | server config, virtual host |
| Status: | Extension |
| Module: | mod_proxy |
The ProxyBlock directive specifies a list of
-words, hosts and/or domains, separated by spaces. HTTP, HTTPS, and
-FTP document requests to sites whose names contain matched words,
-hosts or domains are blocked by the proxy server. The proxy
-module will also attempt to determine IP addresses of list items which
-may be hostnames during startup, and cache them for match test as
-well. Example:
The ProxyBlock directive specifies a list of
+ words, hosts and/or domains, separated by spaces. HTTP, HTTPS, and
+ FTP document requests to sites whose names contain matched words,
+ hosts or domains are blocked by the proxy server. The proxy
+ module will also attempt to determine IP addresses of list items which
+ may be hostnames during startup, and cache them for match test as
+ well. That may slow down the startup time of the server.
- ProxyBlock joes-garage.com some-host.co.uk rocky.wotsamattau.edu
-
+ ProxyBlock joes-garage.com some-host.co.uk rocky.wotsamattau.edu
+
'rocky.wotsamattau.edu' would also be matched if referenced by IP -address.
+rocky.wotsamattau.edu would also be matched if referenced by
+ IP address.
Note that 'wotsamattau' would also be sufficient to match -'wotsamattau.edu'.
+Note that wotsamattau would also be sufficient to match
+ wotsamattau.edu.
Note also that
+Note also that
-
-ProxyBlock *
-
blocks connections to all sites.
+
+ ProxyBlock *
+
blocks connections to all sites.
| Description: | Default domain name for proxied requests |
|---|---|
| Syntax: | ProxyDomain Domain |
| Syntax: | ProxyDomain Domain |
| Context: | server config, virtual host |
| Status: | Extension |
| Module: | mod_proxy |
This directive is only useful for Apache proxy servers within
-intranets. The ProxyDomain directive specifies
-the default domain which the apache proxy server will belong to. If a
-request to a host without a domain name is encountered, a redirection
-response to the same host with the configured Domain appended
-will be generated.
This directive is only useful for Apache proxy servers within
+ intranets. The ProxyDomain directive specifies
+ the default domain which the apache proxy server will belong to. If a
+ request to a host without a domain name is encountered, a redirection
+ response to the same host with the configured Domain appended
+ will be generated.
- ProxyRemote * http://firewall.mycompany.com:81
- NoProxy .mycompany.com 192.168.112.0/21
- ProxyDomain .mycompany.com
-
+ ProxyRemote * http://firewall.mycompany.com:81
+ NoProxy .mycompany.com 192.168.112.0/21
+ ProxyDomain .mycompany.com
+
This directive is useful for reverse-proxy setups, where you want to -have a common look and feel on the error pages seen by the end user. -This also allows for included files (via mod_include's SSI) to get -the error code and act accordingly (default behavior would display -the error page of the proxied server, turning this on shows the SSI -Error message).
+This directive is useful for reverse-proxy setups, where you want to + have a common look and feel on the error pages seen by the end user. + This also allows for included files (via mod_include's SSI) to get + the error code and act accordingly (default behavior would display + the error page of the proxied server, turning this on shows the SSI + Error message).
| Description: | IO buffer size for outgoing HTTP and FTP -connections |
|---|---|
| Syntax: | ProxyIOBufferSize bytes |
| Description: | Determine size of internal data throughput buffer |
| Syntax: | ProxyIOBufferSize bytes |
| Default: | ProxyIOBufferSize 8192 |
| Context: | server config, virtual host |
| Status: | Extension |
| Module: | mod_proxy |
The ProxyIOBufferSize directive adjusts the size
+ of the internal buffer, which is used as a scratchpad for the data between
+ input and output. The size must be less or equal 8192.
In almost every case there's no reason to change that value.
| Description: | Container for directives applied to regular-expression-matched proxied resources |
|---|---|
| Syntax: | <ProxyMatch regex> ...</ProxyMatch> |
| Syntax: | <ProxyMatch regex> ...</ProxyMatch> |
| Context: | server config, virtual host |
| Status: | Extension |
| Module: | mod_proxy |
The <ProxyMatch> directive is
-identical to the <Proxy> directive, except it matches URLs
-using regular expressions.
The <ProxyMatch> directive is
+ identical to the <Proxy> directive, except it matches URLs
+ using regular expressions.
| Description: | Maximium number of proxies that a request can be forwarded through |
|---|---|
| Syntax: | ProxyMaxForwards number |
| Syntax: | ProxyMaxForwards number |
| Default: | ProxyMaxForwards 10 |
| Context: | server config, virtual host |
| Status: | Extension |
| Module: | mod_proxy |
| Compatibility: | Available in Apache 2.0 and later |
The ProxyMaxForwards directive specifies the
-maximum number of proxies through which a request may pass. This is
-set to prevent infinite proxy loops, or a DoS attack.
The ProxyMaxForwards directive specifies the
+ maximum number of proxies through which a request may pass, if there's no
+ Max-Forwards header supplied with the request. This is
+ set to prevent infinite proxy loops, or a DoS attack.
- ProxyMaxForwards 10
-
+ ProxyMaxForwards 15
+
| Description: | Maps remote servers into the local server -URL-space |
|---|---|
| Syntax: | ProxyPass [path] !|url |
| Context: | server config, virtual host |
| Description: | Maps remote servers into the local server URL-space |
| Syntax: | ProxyPass [path] !|url |
| Context: | server config, virtual host, directory |
| Status: | Extension |
| Module: | mod_proxy |
This directive allows remote servers to be mapped into the space of -the local server; the local server does not act as a proxy in the -conventional sense, but appears to be a mirror of the remote -server. path is the name of a local virtual path; -url is a partial URL for the remote server and cannot -include a query string.
+This directive allows remote servers to be mapped into the space of + the local server; the local server does not act as a proxy in the + conventional sense, but appears to be a mirror of the remote + server. path is the name of a local virtual path; url + is a partial URL for the remote server and cannot include a query + string.
-Suppose the local server has address http://wibble.org/;
-then
- ProxyPass /mirror/foo/ http://foo.com/
-
will cause a local request for the
-<http://wibble.org/mirror/foo/bar> to be
-internally converted into a proxy request to
-<http://foo.com/bar>.
-The ! directive is useful in situations where you don't want to reverse-proxy -a subdirectory. eg.
-
- ProxyPass /mirror/foo/i !
- ProxyPass /mirror/foo http://foo.com
-
will proxy all requests to /mirror/foo to foo.com EXCEPT requests made to /mirror/foo/i
+Suppose the local server has address http://example.com/;
+ then
+ ProxyPass /mirror/foo/ http://backend.example.com/
+
When used inside a <Location> section, the first argument is
-ommitted and the local directory is obtained from the <Location>.
will cause a local request for
+ http://example.com/mirror/foo/bar to be internally converted
+ into a proxy request to http://backend.example.com/bar.
If you require a more flexible reverse-proxy configuration, see
-the RewriteRule directive
-with the [P] flag.
The ! directive is useful in situations where you don't want
+ to reverse-proxy a subdirectory, e.g.
+ ProxyPass /mirror/foo/i !
+ ProxyPass /mirror/foo http://backend.example.com
+
will proxy all requests to /mirror/foo to
+ backend.example.com except requests made to
+ /mirror/foo/i.
Order is important. you need to put the exclusions before the + general proxypass directive.
+When used inside a <Location> section, the first argument is ommitted and the local
+ directory is obtained from the <Location>.
If you require a more flexible reverse-proxy configuration, see the
+ RewriteRule directive with the
+ [P] flag.
| Description: | Adjusts the URL in HTTP response headers sent from -a reverse proxied server |
|---|---|
| Syntax: | ProxyPassReverse [path] url |
| Context: | server config, virtual host |
| Description: | Adjusts the URL in HTTP response headers sent from a reverse +proxied server |
| Syntax: | ProxyPassReverse [path] url |
| Context: | server config, virtual host, directory |
| Status: | Extension |
| Module: | mod_proxy |
This directive lets Apache adjust the URL in the Location,
-Content-Location and URI headers on
-HTTP redirect responses. This is essential when Apache is used as
-a reverse proxy to avoid by-passing the reverse proxy because of HTTP
-redirects on the backend servers which stay behind the reverse proxy.
This directive lets Apache adjust the URL in the Location,
+ Content-Location and URI headers on HTTP redirect
+ responses. This is essential when Apache is used as a reverse proxy to avoid
+ by-passing the reverse proxy because of HTTP redirects on the backend
+ servers which stay behind the reverse proxy.
path is the name of a local virtual path.
-url is a partial URL for the remote server - the same way they are
-used for the ProxyPass directive.
path is the name of a local virtual path. url is a
+ partial URL for the remote server - the same way they are used for the
+ ProxyPass directive.
-Example:
-Suppose the local server has address http://wibble.org/; then
- ProxyPass /mirror/foo/ http://foo.com/
- ProxyPassReverse /mirror/foo/ http://foo.com/
-
will not only cause a local request for the
-<http://wibble.org/mirror/foo/bar> to be internally
-converted into a proxy request to <http://foo.com/bar> (the
-functionality ProxyPass provides here). It also takes care of
-redirects the server foo.com sends: when http://foo.com/bar is
-redirected by him to http://foo.com/quux Apache adjusts this to
-http://wibble.org/mirror/foo/quux before forwarding the HTTP
-redirect response to the client. Note that the hostname used for
-constructing the URL is chosen in respect to the setting of the
-UseCanonicalName directive.
-Note that this ProxyPassReverse directive can
-also be used in conjunction with the proxy pass-through feature
-("RewriteRule ... [P]") from
-mod_rewrite because its doesn't depend on a
-corresponding ProxyPass
-directive.
For example, suppose the local server has address
+ http://example.com/; then
When used inside a <Location> section, the first argument is
-ommitted and the local directory is obtained from the <Location>.
+ ProxyPass /mirror/foo/ http://backend.example.com/
+ ProxyPassReverse /mirror/foo/ http://backend.example.com/
+
will not only cause a local request for the
+ http://example.com/mirror/foo/bar to be internally converted
+ into a proxy request to http://backend.example.com/bar
+ (the functionality ProxyPass provides here). It also takes care
+ of redirects the server backend.example.com sends: when
+ http://backend.example.com/bar is redirected by him to
+ http://backend.example.com/quux Apache adjusts this to
+ http://example.com/mirror/foo/quux before forwarding the HTTP
+ redirect response to the client. Note that the hostname used for
+ constructing the URL is chosen in respect to the setting of the UseCanonicalName directive.
Note that this ProxyPassReverse directive can
+ also be used in conjunction with the proxy pass-through feature
+ (RewriteRule ... [P]) from mod_rewrite
+ because its doesn't depend on a corresponding ProxyPass directive.
When used inside a <Location> section, the first argument is ommitted and the local
+ directory is obtained from the <Location>.
| Description: | Use incoming Host HTTP request header for -proxy request |
|---|---|
| Syntax: | ProxyPreserveHost on|off |
| Description: | Use incoming Host HTTP request header for proxy +request |
| Syntax: | ProxyPreserveHost On|Off |
| Default: | ProxyPreserveHost Off |
| Context: | server config, virtual host |
| Status: | Extension |
| Module: | mod_proxy |
| Compatibility: | Available in -Apache 2.0.31 and later. |
| Compatibility: | Available in Apache 2.0.31 and later. |
When enabled, this option will pass the Host: line from the -incoming request to the proxied host, instead of the hostname -specified in the proxypass line. -
-This option should normally be turned 'off'.
+When enabled, this option will pass the Host: line from the incoming + request to the proxied host, instead of the hostname specified in the + proxypass line.
+ +This option should normally be turned Off. It is mostly
+ useful in special configurations like proxied mass name-based virtual
+ hosting, where the original Host header needs to be evaluated by the
+ backend server.
| Description: | Network buffer size for outgoing HTTP and FTP + |
|---|---|
| Description: | Network buffer size for proxied HTTP and FTP connections |
| Syntax: | ProxyReceiveBufferSize bytes |
| Syntax: | ProxyReceiveBufferSize bytes |
| Default: | ProxyReceiveBufferSize 0 |
| Context: | server config, virtual host |
| Status: | Extension |
| Module: | mod_proxy |
The ProxyReceiveBufferSize directive
-specifies an explicit network buffer size for outgoing HTTP and FTP
-connections, for increased throughput. It has to be greater than 512
-or set to 0 to indicate that the system's default buffer size should
-be used.
- ProxyReceiveBufferSize 2048
-
The ProxyReceiveBufferSize directive specifies an
+ explicit (TCP/IP) network buffer size for proxied HTTP and FTP connections,
+ for increased throughput. It has to be greater than 512 or set
+ to 0 to indicate that the system's default buffer size should
+ be used.
+ ProxyReceiveBufferSize 2048
+
| Description: | Remote proxy used to handle certain requests |
|---|---|
| Syntax: | ProxyRemote match remote-server |
| Syntax: | ProxyRemote match remote-server |
| Context: | server config, virtual host |
| Status: | Extension |
| Module: | mod_proxy |
This defines remote proxies to this proxy. match is either the -name of a URL-scheme that the remote server supports, or a partial URL -for which the remote server should be used, or '*' to indicate the -server should be contacted for all requests. remote-server is a -partial URL for the remote server. Syntax:
+This defines remote proxies to this proxy. match is either the
+ name of a URL-scheme that the remote server supports, or a partial URL
+ for which the remote server should be used, or * to indicate
+ the server should be contacted for all requests. remote-server is
+ a partial URL for the remote server. Syntax:
- remote-server = protocol://hostname[:port] -+
+ remote-server =
+ scheme://hostname[:port]
+
protocol is the protocol that should be used to communicate -with the remote server; only "http" is supported by this module.
+scheme is effectively the protocol that should be used to
+ communicate with the remote server; only http is supported by
+ this module.
-Example:
-
- ProxyRemote http://goodguys.com/ http://mirrorguys.com:8000
- ProxyRemote * http://cleversite.com
- ProxyRemote ftp http://ftpproxy.mydomain.com:8080
-
+ ProxyRemote http://goodguys.com/ http://mirrorguys.com:8000
+ ProxyRemote * http://cleversite.com
+ ProxyRemote ftp http://ftpproxy.mydomain.com:8080
+
In the last example, the proxy will forward FTP requests, encapsulated -as yet another HTTP proxy request, to another proxy which can handle -them.
+In the last example, the proxy will forward FTP requests, encapsulated + as yet another HTTP proxy request, to another proxy which can handle + them.
-This option also supports reverse proxy configuration - a backend -webserver can be embedded within a virtualhost URL space even if that -server is hidden by another forward proxy.
+This option also supports reverse proxy configuration - a backend + webserver can be embedded within a virtualhost URL space even if that + server is hidden by another forward proxy.
| Description: | Remote proxy used to handle requests -matched by regular expressions |
|---|---|
| Syntax: | ProxyRemoteMatch regex remote-server |
| Description: | Remote proxy used to handle requests matched by regular +expressions |
| Syntax: | ProxyRemoteMatch regex remote-server |
| Context: | server config, virtual host |
| Status: | Extension |
| Module: | mod_proxy |
The ProxyRemoteMatch is identical
-to the ProxyRemote
-directive, except the first argument is a regular expression
-match against the requested URL.
The ProxyRemoteMatch is identical to the
+ ProxyRemote directive, except the
+ first argument is a regular expression match against the requested URL.
| Description: | Enables forward (standard) proxy requests |
|---|---|
| Syntax: | ProxyRequests on|off |
| Syntax: | ProxyRequests On|Off |
| Default: | ProxyRequests Off |
| Context: | server config, virtual host |
| Status: | Extension |
| Module: | mod_proxy |
This allows or prevents Apache from functioning as a forward proxy
-server. (Setting ProxyRequests to 'off' does not disable use of the
-ProxyPass directive.)
This allows or prevents Apache from functioning as a forward proxy
+ server. (Setting ProxyRequests to Off does not disable use of
+ the ProxyPass directive.)
In a typical reverse proxy configuration, this option should be set to -'off'.
+In a typical reverse proxy configuration, this option should be set to
+ Off.
Do not enable proxying with ProxyRequests until you have
-secured your server. Open proxy servers are
-dangerous both to your network and to the Internet at large.
In order to get the functionality of proxying HTTP or FTP sites, you
+ need also mod_proxy_http or mod_proxy_ftp
+ (or both) present in the server.
Do not enable proxying with ProxyRequests until you have secured your server. Open proxy servers are dangerous
+ both to your network and to the Internet at large.
| Description: | Network timeout for proxied requests |
|---|---|
| Syntax: | ProxyTimeout seconds |
| Syntax: | ProxyTimeout seconds |
| Default: | ProxyTimeout 300 |
| Context: | server config, virtual host |
| Status: | Extension |
| Module: | mod_proxy |
| Compatibility: | Available in -Apache 2.0.31 and later |
| Compatibility: | Available in Apache 2.0.31 and later |
This directive allows a user to specifiy a timeout on proxy requests. -This is usefull when you have a slow/buggy appserver which hangs, -and you would rather just return a timeout and fail gracefully instead -of waiting however long it takes the server to return -
+This directive allows a user to specifiy a timeout on proxy requests. + This is useful when you have a slow/buggy appserver which hangs, and you + would rather just return a timeout and fail gracefully instead of waiting + however long it takes the server to return.
| Description: | Information provided in the Via HTTP response header for proxied requests |
|---|---|
| Syntax: | ProxyVia on|off|full|block |
| Default: | ProxyVia off |
| Syntax: | ProxyVia On|Off|Full|Block |
| Default: | ProxyVia Off |
| Context: | server config, virtual host |
| Status: | Extension |
| Module: | mod_proxy |
This directive controls the use of the Via: HTTP
-header by the proxy. Its intended use is to control the flow of of
-proxy requests along a chain of proxy servers. See RFC2068 (HTTP/1.1)
-for an explanation of Via: header lines.
This directive controls the use of the Via: HTTP
+ header by the proxy. Its intended use is to control the flow of of
+ proxy requests along a chain of proxy servers. See RFC 2616 (HTTP/1.1), section
+ 14.45 for an explanation of Via: header lines.
Via: header,
-it is passed through unchanged.Off, which is the default, no special processing
+ is performed. If a request or reply contains a Via: header,
+ it is passed through unchanged.Via: header line added for
-the current host.On, each request and reply will get a
+ Via: header line added for the current host.Via: header
-line will additionally have the Apache server version shown as a
-Via: comment field.Full, each generated Via: header
+ line will additionally have the Apache server version shown as a
+ Via: comment field.Via: header lines
-removed. No new Via: header will be generated.Block, every proxy request will have all its
+ Via: header lines removed. No new Via: header will
+ be generated.Do not enable proxying with
This module implements a proxy/gateway for Apache. It implements
-proxying capability for
-FTP,
-CONNECT (for SSL),
-HTTP/0.9,
-HTTP/1.0, and
-HTTP/1.1.
-The module can be configured to connect to other proxy modules for these
-and other protocols.
This module implements a proxy/gateway for Apache. It implements
+ proxying capability for FTP, CONNECT (for SSL),
+ HTTP/0.9, HTTP/1.0, and HTTP/1.1.
+ The module can be configured to connect to other proxy modules for these
+ and other protocols.
This module was experimental in Apache 1.1.x. Improvements and bugfixes -were made in Apache v1.2.x and Apache v1.3.x, then the module underwent a major -overhaul for Apache v2.0. The protocol support was upgraded to HTTP/1.1, -and filter support was enabled.
+This module was experimental in Apache 1.1.x. Improvements and bugfixes
+ were made in Apache v1.2.x and Apache v1.3.x, then the module underwent a
+ major overhaul for Apache v2.0. The protocol support was upgraded to
+ HTTP/1.1, and filter support was enabled.
Please note that the caching function present in -mod_proxy up to Apache v1.3.x has been removed from -mod_proxy and will be incorporated into a new module, mod_cache. In other words: -the Apache 2.0.x-Proxy doesn't -cache at all - all caching functionality has been moved into mod_cache, -which is capable of caching any content, not only content from proxy. -
- -If you need to use SSL when contacting remote servers, have a look at the
-SSLProxy* directives in
Do not enable proxying with
During the overhaul process the
Please note that the caching function present in
If you need to use SSL when contacting remote servers, have a look at the
+ SSLProxy* directives in
Apache can be configured in both a forward and + reverse proxy configuration.
-A forward proxy is an intermediate system that enables a + browser to connect to a remote network to which it normally does not have + access. A forward proxy can also be used to cache data, reducing load on + the networks between the forward proxy and the remote webserver.
-Apache can be configured in both a forward and reverse -proxy configuration.
+Apache's
A forward proxy is an intermediate system that enables a browser to connect to a -remote network to which it normally does not have access. A forward proxy -can also be used to cache data, reducing load on the networks between the -forward proxy and the remote webserver.
+A reverse proxy is a webserver system that is capable of + serving webpages sourced from other webservers - in addition to webpages + on disk or generated dynamically by CGI - making these pages look like + they originated at the reverse proxy.
-Apache's mod_proxy can be figured to behave like a forward proxy
-using the
When configured with the mod_cache module the reverse proxy can act as
+ a cache for slower backend webservers. The reverse proxy can also enable
+ advanced URL strategies and management techniques, allowing webpages
+ served using different webserver systems or architectures to coexist
+ inside the same URL space. Reverse proxy systems are also ideal for
+ implementing centralised logging websites with many or diverse website
+ backends. Complex multi-tier webserver systems can be constructed using an
+
A reverse proxy is a webserver system that is capable of serving webpages -sourced from other webservers - in addition to webpages on disk or generated -dynamically by CGI - making these pages look like they originated at the -reverse proxy.
+The reverse proxy is configured using the
When configured with the mod_cache module the reverse -proxy can act as a cache for slower backend webservers. The reverse proxy -can also enable advanced URL strategies and management techniques, allowing -webpages served using different webserver systems or architectures to -coexist inside the same URL space. Reverse proxy systems are also ideal for -implementing centralised logging websites with many or diverse website -backends. Complex multi-tier webserver systems can be constructed using an -Apache mod_proxy frontend and any number of backend webservers.
+You can control who can access your proxy via the
The reverse proxy is configured using the
-
When configuring a reverse proxy, access control takes on the
+ attributes of the normal server
You probably don't have that particular file type defined as
+ application/octet-stream in your proxy's mime.types
+ configuration file. A useful line can be
You can control who can access your proxy via the
-
application/octet-stream bin dms lha lzh exe class tgz taz+
In the rare situation where you must download a specific file using the
+ FTP ASCII transfer method (while the default transfer is in
+ binary mode), you can override ;type=a to force an
+ ASCII transfer. (FTP Directory listings are always executed in ASCII mode,
+ however.)
When configuring a reverse proxy, access control takes on the
-attributes of the normal server
An FTP URI is interpreted relative to the home directory of the user
+ who is logging in. Alas, to reach higher directory levels you cannot
+ use /../, as the dots are interpreted by the browser and not actually
+ sent to the FTP server. To address this problem, the so called Squid
+ %2f hack was implemented in the Apache FTP proxy; it is a
+ solution which is also used by other popular proxy servers like the Squid Proxy Cache. By
+ prepending /%2f to the path of your request, you can make
+ such a proxy change the FTP starting directory to / (instead
+ of the home directory). For example, to retrieve the file
+ /etc/motd, you would use the URL:
You probably don't have that particular file type defined as -application/octet-stream in your proxy's mime.types configuration -file. A useful line can be
+To log in to an FTP server by username and password, Apache uses + different strategies. In absense of a user name and password in the URL + altogether, Apache sends an anomymous login to the FTP server, + i.e.,
-This works for all popular FTP servers which are configured for + anonymous access.
-In the rare situation where you must download a specific file using the FTP
-ASCII transfer method (while the default transfer is in
-binary mode), you can override mod_proxy's default by
-suffixing the request with ;type=a to force an ASCII transfer.
-(FTP Directory listings are always executed in ASCII mode, however.)
For a personal login with a specific username, you can embed the user + name into the URL, like in:
--An FTP URI is interpreted relative to the home directory of the user -who is logging in. Alas, to reach higher directory levels you cannot -use /../, as the dots are interpreted by the browser and not actually -sent to the FTP server. To address this problem, the so called "Squid -%2f hack" was implemented in the Apache FTP proxy; it is is a solution -which is also used by other popular proxy servers like the Squid Proxy Cache. By -prepending /%2f to the path of your request, you can make such a proxy -change the FTP starting directory to / (instead of the home -directory).
+If the FTP server asks for a password when given this username (which
+ it should), then Apache will reply with a 401 (Authorization
+ required) response, which causes the Browser to pop up the
+ username/password dialog. Upon entering the password, the connection
+ attempt is retried, and if successful, the requested resource is
+ presented. The advantage of this procedure is that your browser does not
+ display the password in cleartext (which it would if you had used
Example: To retrieve the file
-/etc/motd, you would use the URL
in the first place).
--To log in to an FTP server by username and password, Apache -uses different strategies. -In absense of a user name and password in the URL altogether, -Apache sends an anomymous login to the FTP server, i.e.,
-This works for all popular FTP servers which are configured for -anonymous access.
+The password which is transmitted in such a way is not encrypted on + its way. It travels between your browser and the Apache proxy server in + a base64-encoded cleartext string, and between the Apache proxy and the + FTP server as plaintext. You should therefore think twice before + accessing your FTP server via HTTP (or before accessing your personal + files via FTP at all!) When using unsecure channels, an eavesdropper + might intercept your password on its way.
+For a personal login with a specific username, you can embed
-the user name into the URL, like in:
-ftp://username@host/myfile. If the FTP server
-asks for a password when given this username (which it should),
-then Apache will reply with a [401 Authorization required] response,
-which causes the Browser to pop up the username/password dialog.
-Upon entering the password, the connection attempt is retried,
-and if successful, the requested resource is presented.
-The advantage of this procedure is that your browser does not
-display the password in cleartext (which it would if you had used
-ftp://username:password@host/myfile in
-the first place).
If you're using the
An Apache proxy server situated in an intranet needs to forward
+ external requests through the company's firewall. However, when it has to
+ access resources within the intranet, it can bypass the firewall when
+ accessing hosts. The
Users within an intranet tend to omit the local domain name from their
+ WWW requests, thus requesting "http://somehost/" instead of
+ http://somehost.example.com/. Some commercial proxy servers
+ let them get away with this and simply serve the request, implying a
+ configured local domain. When the
If you're using the
For circumstances where you have a application server which doesn't
+ implement keepalives or HTTP/1.1 properly, there are 2 environment
+ variables which when set send a HTTP/1.0 with no keepalive. These are set
+ via the
An Apache proxy server situated in an intranet needs to forward
-external requests through the company's firewall. However, when it has
-to access resources within the intranet, it can bypass the firewall
-when accessing hosts. The
Users within an intranet tend to omit the local domain name from their
-WWW requests, thus requesting "http://somehost/" instead of
-"http://somehost.my.dom.ain/". Some commercial proxy servers let them get
-away with this and simply serve the request, implying a configured
-local domain. When the
For circumstances where you have a application server which doesn't implement
-keepalives or HTTP/1.1 properly, there are 2 environment variables which when
-set send a HTTP/1.0 with no keepalive. These are set via the
These are the 'force-proxy-request-1.0' and 'proxy-nokeepalive' notes.
- -These are the force-proxy-request-1.0 and
+ proxy-nokeepalive notes.
Directives placed in
Directives placed in
For example, the following will allow only hosts in
-yournetwork.example.com to access content via your
-proxy server:
For example, the following will allow only hosts in
+ yournetwork.example.com to access content via your proxy
+ server:
The following example will process all files in the
-foo directory of example.com through the
-INCLUDES filter when they are sent through the proxy
-server:
The following example will process all files in the foo
+ directory of example.com through the INCLUDES
+ filter when they are sent through the proxy server:
The
IsErrorThe
IgnoreIsErrorStartBodyIgnoreStartBodyThe
The
When enabled, this option will pass the Host: line from the -incoming request to the proxied host, instead of the hostname -specified in the proxypass line. -
-This option should normally be turned 'off'.
+When enabled, this option will pass the Host: line from the incoming + request to the proxied host, instead of the hostname specified in the + proxypass line.
+ +This option should normally be turned Off. It is mostly
+ useful in special configurations like proxied mass name-based virtual
+ hosting, where the original Host header needs to be evaluated by the
+ backend server.
This allows or prevents Apache from functioning as a forward proxy
-server. (Setting ProxyRequests to 'off' does not disable use of the
-
This allows or prevents Apache from functioning as a forward proxy
+ server. (Setting ProxyRequests to Off does not disable use of
+ the
In a typical reverse proxy configuration, this option should be set to -'off'.
+In a typical reverse proxy configuration, this option should be set to
+ Off.
Do not enable proxying with
In order to get the functionality of proxying HTTP or FTP sites, you
+ need also
Do not enable proxying with
This defines remote proxies to this proxy. match is either the -name of a URL-scheme that the remote server supports, or a partial URL -for which the remote server should be used, or '*' to indicate the -server should be contacted for all requests. remote-server is a -partial URL for the remote server. Syntax:
+This defines remote proxies to this proxy. match is either the
+ name of a URL-scheme that the remote server supports, or a partial URL
+ for which the remote server should be used, or * to indicate
+ the server should be contacted for all requests. remote-server is
+ a partial URL for the remote server. Syntax:
- remote-server = protocol://hostname[:port] -+
protocol is the protocol that should be used to communicate -with the remote server; only "http" is supported by this module.
+scheme is effectively the protocol that should be used to
+ communicate with the remote server; only http is supported by
+ this module.
-Example:
-In the last example, the proxy will forward FTP requests, encapsulated -as yet another HTTP proxy request, to another proxy which can handle -them.
+In the last example, the proxy will forward FTP requests, encapsulated + as yet another HTTP proxy request, to another proxy which can handle + them.
-This option also supports reverse proxy configuration - a backend -webserver can be embedded within a virtualhost URL space even if that -server is hidden by another forward proxy.
+This option also supports reverse proxy configuration - a backend + webserver can be embedded within a virtualhost URL space even if that + server is hidden by another forward proxy.
The
The
This directive allows remote servers to be mapped into the space of -the local server; the local server does not act as a proxy in the -conventional sense, but appears to be a mirror of the remote -server. path is the name of a local virtual path; -url is a partial URL for the remote server and cannot -include a query string.
+This directive allows remote servers to be mapped into the space of + the local server; the local server does not act as a proxy in the + conventional sense, but appears to be a mirror of the remote + server. path is the name of a local virtual path; url + is a partial URL for the remote server and cannot include a query + string.
-Suppose the local server has address http://wibble.org/;
-then
will cause a local request for the
-<http://wibble.org/mirror/foo/bar> to be
-internally converted into a proxy request to
-<http://foo.com/bar>.
-The ! directive is useful in situations where you don't want to reverse-proxy -a subdirectory. eg.
-will proxy all requests to /mirror/foo to foo.com EXCEPT requests made to /mirror/foo/i
+Suppose the local server has address http://example.com/;
+ then
When used inside a
will cause a local request for
+ http://example.com/mirror/foo/bar to be internally converted
+ into a proxy request to http://backend.example.com/bar.
If you require a more flexible reverse-proxy configuration, see
-the [P] flag.
The ! directive is useful in situations where you don't want
+ to reverse-proxy a subdirectory, e.g.
will proxy all requests to /mirror/foo to
+ backend.example.com except requests made to
+ /mirror/foo/i.
Order is important. you need to put the exclusions before the + general proxypass directive.
+When used inside a
If you require a more flexible reverse-proxy configuration, see the
+ [P] flag.
This directive lets Apache adjust the URL in the Location,
-Content-Location and URI headers on
-HTTP redirect responses. This is essential when Apache is used as
-a reverse proxy to avoid by-passing the reverse proxy because of HTTP
-redirects on the backend servers which stay behind the reverse proxy.
This directive lets Apache adjust the URL in the Location,
+ Content-Location and URI headers on HTTP redirect
+ responses. This is essential when Apache is used as a reverse proxy to avoid
+ by-passing the reverse proxy because of HTTP redirects on the backend
+ servers which stay behind the reverse proxy.
path is the name of a local virtual path.
-url is a partial URL for the remote server - the same way they are
-used for the
path is the name of a local virtual path. url is a
+ partial URL for the remote server - the same way they are used for the
+
-Example:
-Suppose the local server has address http://wibble.org/; then
will not only cause a local request for the
-<http://wibble.org/mirror/foo/bar> to be internally
-converted into a proxy request to <http://foo.com/bar> (the
-functionality ProxyPass provides here). It also takes care of
-redirects the server foo.com sends: when http://foo.com/bar is
-redirected by him to http://foo.com/quux Apache adjusts this to
-http://wibble.org/mirror/foo/quux before forwarding the HTTP
-redirect response to the client. Note that the hostname used for
-constructing the URL is chosen in respect to the setting of the
-
-Note that this RewriteRule ... [P]") from
-
For example, suppose the local server has address
+ http://example.com/; then
When used inside a
will not only cause a local request for the
+ http://example.com/mirror/foo/bar to be internally converted
+ into a proxy request to http://backend.example.com/bar
+ (the functionality ProxyPass provides here). It also takes care
+ of redirects the server backend.example.com sends: when
+ http://backend.example.com/bar is redirected by him to
+ http://backend.example.com/quux Apache adjusts this to
+ http://example.com/mirror/foo/quux before forwarding the HTTP
+ redirect response to the client. Note that the hostname used for
+ constructing the URL is chosen in respect to the setting of the
Note that this RewriteRule ... [P]) from
When used inside a
CONNECT through
-the proxyCONNECT through the
+proxyThe CONNECT method may
-connect. Today's browsers use this method when a https
-connection is requested and proxy tunneling over http is in
-effect.
By default, only the default https port (443) and the
-default snews port (563) are enabled. Use the
-
The CONNECT method may
+ connect. Today's browsers use this method when a https
+ connection is requested and proxy tunneling over HTTP is in effect.
By default, only the default https port (443) and the
+ default snews port (563) are enabled. Use the
+
Note that you'll need to have CONNECT at
+ all.
The
The
'rocky.wotsamattau.edu' would also be matched if referenced by IP -address.
+rocky.wotsamattau.edu would also be matched if referenced by
+ IP address.
Note that 'wotsamattau' would also be sufficient to match -'wotsamattau.edu'.
+Note that wotsamattau would also be sufficient to match
+ wotsamattau.edu.
Note also that
+Note also that
-blocks connections to all sites.
+blocks connections to all sites.
The
The 512 or set
+ to 0 to indicate that the system's default buffer size should
+ be used.
The 8192.
In almost every case there's no reason to change that value.
The
The Max-Forwards header supplied with the request. This is
+ set to prevent infinite proxy loops, or a DoS attack.
This directive is only useful for Apache proxy servers within
-intranets. The
This directive is only useful for Apache proxy servers within
+ intranets. The
The host arguments to the NoProxy directive are one of the -following type list:
-The host arguments to the
.com .apache.org..MyDomain.com and
- .mydomain.com. (note the trailing period) are
- considered equal. Since a domain comparison does not involve a DNS
- lookup, it is much more efficient than subnet comparison.A Domain is a partially qualified DNS domain name, preceded + by a period. It represents a list of hosts which logically belong to the + same DNS domain or zone (i.e., the suffixes of the hostnames are + all ending in Domain).
+ +To distinguish Domains from Hostnames (both syntactically and semantically; a DNS domain can + have a DNS A record, too!), Domains are always written with a + leading period.
+ +Domain name comparisons are done without regard to the case, and
+ Domains are always assumed to be anchored in the root of the
+ DNS tree, therefore two domains .MyDomain.com and
+ .mydomain.com. (note the trailing period) are considered
+ equal. Since a domain comparison does not involve a DNS lookup, it is much
+ more efficient than subnet comparison.
192.168 or 192.168.0.0255.255.0.0)192.168.112.0/21192.168.112.0/21 with a netmask of 21
- valid bits (also used in the form 255.255.248.0)A SubNet is a partially qualified internet address in + numeric (dotted quad) form, optionally followed by a slash and the netmask, + specified as the number of significant bits in the SubNet. It is + used to represent a subnet of hosts which can be reached over a common + network interface. In the absence of the explicit net mask it is assumed + that omitted (or zero valued) trailing digits specify the mask. (In this + case, the netmask can only be multiples of 8 bits wide.) Examples:
+ +192.168 or 192.168.0.0255.255.0.0)192.168.112.0/21192.168.112.0/21 with a netmask of 21
+ valid bits (also used in the form 255.255.248.0)As a degenerate case, a SubNet with 32 valid bits is the + equivalent to an IPAddr, while a SubNet with zero + valid bits (e.g., 0.0.0.0/0) is the same as the constant + _Default_, matching any IP address.
A IPAddr represents a fully qualified internet address in + numeric (dotted quad) form. Usually, this address represents a host, but + there need not necessarily be a DNS domain name connected with the + address.
+An IPAddr does not need to be resolved by the DNS system, so + it can result in more effective apache performance.
+prep.ai.mit.edu
- www.apache.org.WWW.MyDomain.com
- and www.mydomain.com. (note the trailing period) are
- considered equal.A Hostname is a fully qualified DNS domain name which can + be resolved to one or more IPAddrs via the + DNS domain name service. It represents a logical host (in contrast to + Domains, see above) and must be resolvable + to at least one IPAddr (or often to a list + of hosts with different IPAddrs).
+ +In many situations, it is more effective to specify an IPAddr in place of a Hostname since a + DNS lookup can be avoided. Name resolution in Apache can take a remarkable + deal of time when the connection to the name server uses a slow PPP + link.
+Hostname comparisons are done without regard to the case,
+ and Hostnames are always assumed to be anchored in the root
+ of the DNS tree, therefore two hosts WWW.MyDomain.com
+ and www.mydomain.com. (note the trailing period) are
+ considered equal.
This directive allows a user to specifiy a timeout on proxy requests. -This is usefull when you have a slow/buggy appserver which hangs, -and you would rather just return a timeout and fail gracefully instead -of waiting however long it takes the server to return -
+This directive allows a user to specifiy a timeout on proxy requests. + This is useful when you have a slow/buggy appserver which hangs, and you + would rather just return a timeout and fail gracefully instead of waiting + however long it takes the server to return.
This directive is only useful for Apache proxy servers within
-intranets. The
This directive is only useful for Apache proxy servers within
+ intranets. The
Via HTTP response
header for proxied requestsThis directive controls the use of the Via: HTTP
-header by the proxy. Its intended use is to control the flow of of
-proxy requests along a chain of proxy servers. See RFC2068 (HTTP/1.1)
-for an explanation of Via: header lines.
This directive controls the use of the Via: HTTP
+ header by the proxy. Its intended use is to control the flow of of
+ proxy requests along a chain of proxy servers. See RFC 2616 (HTTP/1.1), section
+ 14.45 for an explanation of Via: header lines.
Via: header,
-it is passed through unchanged.Off, which is the default, no special processing
+ is performed. If a request or reply contains a Via: header,
+ it is passed through unchanged.Via: header line added for
-the current host.On, each request and reply will get a
+ Via: header line added for the current host.Via: header
-line will additionally have the Apache server version shown as a
-Via: comment field.Full, each generated Via: header
+ line will additionally have the Apache server version shown as a
+ Via: comment field.Via: header lines
-removed. No new Via: header will be generated.Block, every proxy request will have all its
+ Via: header lines removed. No new Via: header will
+ be generated.Via: header will be generated.
This directive is useful for reverse-proxy setups, where you want to -have a common look and feel on the error pages seen by the end user. -This also allows for included files (via mod_include's SSI) to get -the error code and act accordingly (default behavior would display -the error page of the proxied server, turning this on shows the SSI -Error message).
+This directive is useful for reverse-proxy setups, where you want to + have a common look and feel on the error pages seen by the end user. + This also allows for included files (via mod_include's SSI) to get + the error code and act accordingly (default behavior would display + the error page of the proxied server, turning this on shows the SSI + Error message).
CONNECT through
-the proxyCONNECT through the
+proxy.htaccess-Dateien
erlaubt sind.Via HTTP response
+Via HTTP response
header for proxied requestsCONNECT through
-the proxyCONNECT through the
+proxy.htaccess filesVia HTTP response
+Via HTTP response
header for proxied requestsCONNECT through
-the proxyCONNECT through the
+proxy.htaccess filesVia HTTP response
+Via HTTP response
header for proxied requests