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+<?xml version="1.0" encoding="ISO-8859-1"?>
+<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
+<html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en"><head><!--
+ XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
+ This file is generated from xml source: DO NOT EDIT
+ XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
+ -->
+<title>mod_proxy - Apache HTTP Server</title>
+<link href="../style/css/manual.css" rel="stylesheet" media="all" type="text/css" title="Main stylesheet" />
+<link href="../style/css/manual-loose-100pc.css" rel="alternate stylesheet" media="all" type="text/css" title="No Sidebar - Default font size" />
+<link href="../style/css/manual-print.css" rel="stylesheet" media="print" type="text/css" />
+<link href="../images/favicon.ico" rel="shortcut icon" /></head>
+<body>
+<div id="page-header">
+<p class="menu"><a href="../mod/">Modules</a> | <a href="../mod/directives.html">Directives</a> | <a href="../faq/">FAQ</a> | <a href="../glossary.html">Glossary</a> | <a href="../sitemap.html">Sitemap</a></p>
+<p class="apache">Apache HTTP Server Version 2.0</p>
+<img alt="" src="../images/feather.gif" /></div>
+<div class="up"><a href="./"><img title="&lt;-" alt="&lt;-" src="../images/left.gif" /></a></div>
+<div id="path">
+<a href="http://www.apache.org/">Apache</a> &gt; <a href="http://httpd.apache.org/">HTTP Server</a> &gt; <a href="http://httpd.apache.org/docs/">Documentation</a> &gt; <a href="../">Version 2.0</a> &gt; <a href="./">Modules</a></div>
+<div id="page-content">
+<div id="preamble"><h1>Apache Module mod_proxy</h1>
+<div class="toplang">
+<p><span>Available Languages: </span><a href="../en/mod/mod_proxy.html" title="English">&nbsp;en&nbsp;</a></p>
+</div>
+<table class="module"><tr><th><a href="module-dict.html#Description">Description:</a></th><td>HTTP/1.1 proxy/gateway server</td></tr>
+<tr><th><a href="module-dict.html#Status">Status:</a></th><td>Extension</td></tr>
+<tr><th><a href="module-dict.html#ModuleIdentifier">Module Identifier:</a></th><td>proxy_module</td></tr>
+<tr><th><a href="module-dict.html#SourceFile">Source File:</a></th><td>mod_proxy.c</td></tr></table>
+<h3>Summary</h3>
+
+ <div class="warning"><h3>Warning</h3>
+ <p>Do not enable proxying with <code class="directive"><a href="#proxyrequests">ProxyRequests</a></code> until you have <a href="#access">secured your server</a>. Open proxy servers are dangerous both to your
+ network and to the Internet at large.</p>
+ </div>
+
+ <p>This module implements a proxy/gateway for Apache. It implements
+ proxying capability for <code>FTP</code>, <code>CONNECT</code> (for SSL),
+ <code>HTTP/0.9</code>, <code>HTTP/1.0</code>, and <code>HTTP/1.1</code>.
+ The module can be configured to connect to other proxy modules for these
+ and other protocols.</p>
+
+ <p>Apache's proxy features are divided into several modules in
+ addition to <code class="module"><a href="../mod/mod_proxy.html">mod_proxy</a></code>:
+ <code class="module"><a href="../mod/mod_proxy_http.html">mod_proxy_http</a></code>, <code class="module"><a href="../mod/mod_proxy_ftp.html">mod_proxy_ftp</a></code>
+ and <code class="module"><a href="../mod/mod_proxy_connect.html">mod_proxy_connect</a></code>. Thus, if you want to use
+ one or more of the particular proxy functions, load
+ <code class="module"><a href="../mod/mod_proxy.html">mod_proxy</a></code> <em>and</em> the appropriate module(s)
+ into the server (either statically at compile-time or dynamically
+ via the <code class="directive"><a href="../mod/mod_so.html#loadmodule">LoadModule</a></code>
+ directive).</p>
+
+ <p>In addition, extended features are provided by other modules.
+ Caching is provided by <code class="module"><a href="../mod/mod_cache.html">mod_cache</a></code> and related
+ modules. The ability to contact remote servers using the SSL/TLS
+ protocol is provided by the <code>SSLProxy*</code> directives of
+ <code class="module"><a href="../mod/mod_ssl.html">mod_ssl</a></code>. These additional modules will need
+ to be loaded and configured to take advantage of these features.</p>
+</div>
+<div id="quickview"><h3 class="directives">Directives</h3>
+<ul id="toc">
+<li><img alt="" src="../images/down.gif" /> <a href="#allowconnect">AllowCONNECT</a></li>
+<li><img alt="" src="../images/down.gif" /> <a href="#noproxy">NoProxy</a></li>
+<li><img alt="" src="../images/down.gif" /> <a href="#proxy">&lt;Proxy&gt;</a></li>
+<li><img alt="" src="../images/down.gif" /> <a href="#proxybadheader">ProxyBadHeader</a></li>
+<li><img alt="" src="../images/down.gif" /> <a href="#proxyblock">ProxyBlock</a></li>
+<li><img alt="" src="../images/down.gif" /> <a href="#proxydomain">ProxyDomain</a></li>
+<li><img alt="" src="../images/down.gif" /> <a href="#proxyerroroverride">ProxyErrorOverride</a></li>
+<li><img alt="" src="../images/down.gif" /> <a href="#proxyftpdircharset">ProxyFtpDirCharset</a></li>
+<li><img alt="" src="../images/down.gif" /> <a href="#proxyiobuffersize">ProxyIOBufferSize</a></li>
+<li><img alt="" src="../images/down.gif" /> <a href="#proxymatch">&lt;ProxyMatch&gt;</a></li>
+<li><img alt="" src="../images/down.gif" /> <a href="#proxymaxforwards">ProxyMaxForwards</a></li>
+<li><img alt="" src="../images/down.gif" /> <a href="#proxypass">ProxyPass</a></li>
+<li><img alt="" src="../images/down.gif" /> <a href="#proxypassreverse">ProxyPassReverse</a></li>
+<li><img alt="" src="../images/down.gif" /> <a href="#proxypreservehost">ProxyPreserveHost</a></li>
+<li><img alt="" src="../images/down.gif" /> <a href="#proxyreceivebuffersize">ProxyReceiveBufferSize</a></li>
+<li><img alt="" src="../images/down.gif" /> <a href="#proxyremote">ProxyRemote</a></li>
+<li><img alt="" src="../images/down.gif" /> <a href="#proxyremotematch">ProxyRemoteMatch</a></li>
+<li><img alt="" src="../images/down.gif" /> <a href="#proxyrequests">ProxyRequests</a></li>
+<li><img alt="" src="../images/down.gif" /> <a href="#proxytimeout">ProxyTimeout</a></li>
+<li><img alt="" src="../images/down.gif" /> <a href="#proxyvia">ProxyVia</a></li>
+</ul>
+<h3>Topics</h3>
+<ul id="topics">
+<li><img alt="" src="../images/down.gif" /> <a href="#forwardreverse">Forward and Reverse Proxies</a></li>
+<li><img alt="" src="../images/down.gif" /> <a href="#examples">Basic Examples</a></li>
+<li><img alt="" src="../images/down.gif" /> <a href="#access">Controlling access to your proxy</a></li>
+<li><img alt="" src="../images/down.gif" /> <a href="#ftp-proxy">FTP Proxy</a></li>
+<li><img alt="" src="../images/down.gif" /> <a href="#startup">Slow Startup</a></li>
+<li><img alt="" src="../images/down.gif" /> <a href="#intranet">Intranet Proxy</a></li>
+<li><img alt="" src="../images/down.gif" /> <a href="#envsettings">Protocol Adjustments</a></li>
+</ul><h3>See also</h3>
+<ul class="seealso">
+<li><code class="module"><a href="../mod/mod_cache.html">mod_cache</a></code></li>
+<li><code class="module"><a href="../mod/mod_proxy_http.html">mod_proxy_http</a></code></li>
+<li><code class="module"><a href="../mod/mod_proxy_ftp.html">mod_proxy_ftp</a></code></li>
+<li><code class="module"><a href="../mod/mod_proxy_connect.html">mod_proxy_connect</a></code></li>
+<li><code class="module"><a href="../mod/mod_ssl.html">mod_ssl</a></code></li>
+</ul></div>
+<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
+<div class="section">
+<h2><a name="forwardreverse" id="forwardreverse">Forward and Reverse Proxies</a></h2>
+ <p>Apache can be configured in both a <dfn>forward</dfn> and
+ <dfn>reverse</dfn> proxy mode.</p>
+
+ <p>An ordinary <dfn>forward proxy</dfn> is an intermediate
+ server that sits between the client and the <em>origin
+ server</em>. In order to get content from the origin server,
+ the client sends a request to the proxy naming the origin server
+ as the target and the proxy then requests the content from the
+ origin server and returns it to the client. The client must be
+ specially configured to use the forward proxy to access other
+ sites.</p>
+
+ <p>A typical usage of a forward proxy is to provide Internet
+ access to internal clients that are otherwise restricted by a
+ firewall. The forward proxy can also use caching (as provided
+ by <code class="module"><a href="../mod/mod_cache.html">mod_cache</a></code>) to reduce network usage.</p>
+
+ <p>The forward proxy is activated using the <code class="directive"><a href="#proxyrequests">ProxyRequests</a></code> directive. Because
+ forward proxys allow clients to access arbitrary sites through
+ your server and to hide their true origin, it is essential that
+ you <a href="#access">secure your server</a> so that only
+ authorized clients can access the proxy before activating a
+ forward proxy.</p>
+
+ <p>A <dfn>reverse proxy</dfn>, by contrast, appears to the
+ client just like an ordinary web server. No special
+ configuration on the client is necessary. The client makes
+ ordinary requests for content in the name-space of the reverse
+ proxy. The reverse proxy then decides where to send those
+ requests, and returns the content as if it was itself the
+ origin.</p>
+
+ <p>A typical usage of a reverse proxy is to provide Internet
+ users access to a server that is behind a firewall. Reverse
+ proxies can also be used to balance load among several back-end
+ servers, or to provide caching for a slower back-end server.
+ In addition, reverse proxies can be used simply to bring
+ several servers into the same URL space.</p>
+
+ <p>A reverse proxy is activated using the <code class="directive"><a href="#proxypass">ProxyPass</a></code> directive or the
+ <code>[P]</code> flag to the <code class="directive"><a href="../mod/mod_rewrite.html#rewriterule">RewriteRule</a></code> directive. It is
+ <strong>not</strong> necessary to turn <code class="directive"><a href="#proxyrequests">ProxyRequests</a></code> on in order to
+ configure a reverse proxy.</p>
+ </div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
+<div class="section">
+<h2><a name="examples" id="examples">Basic Examples</a></h2>
+
+ <p>The examples below are only a very basic idea to help you
+ get started. Please read the documentation on the individual
+ directives.</p>
+
+ <p>In addition, if you wish to have caching enabled, consult
+ the documentation from <code class="module"><a href="../mod/mod_cache.html">mod_cache</a></code>.</p>
+
+ <div class="example"><h3>Forward Proxy</h3><p><code>
+ ProxyRequests On<br />
+ ProxyVia On<br />
+ <br />
+ &lt;Proxy *&gt;<br />
+ <span class="indent">
+ Order deny,allow<br />
+ Deny from all<br />
+ Allow from internal.example.com<br />
+ </span>
+ &lt;/Proxy&gt;
+ </code></p></div>
+
+ <div class="example"><h3>Reverse Proxy</h3><p><code>
+ ProxyRequests Off<br />
+ <br />
+ &lt;Proxy *&gt;<br />
+ <span class="indent">
+ Order deny,allow<br />
+ Allow from all<br />
+ </span>
+ &lt;/Proxy&gt;<br />
+ <br />
+ ProxyPass /foo http://foo.example.com/bar<br />
+ ProxyPassReverse /foo http://foo.example.com/bar
+ </code></p></div>
+ </div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
+<div class="section">
+<h2><a name="access" id="access">Controlling access to your proxy</a></h2>
+ <p>You can control who can access your proxy via the <code class="directive"><a href="#proxy">&lt;Proxy&gt;</a></code> control block as in
+ the following example:</p>
+
+ <div class="example"><p><code>
+ &lt;Proxy *&gt;<br />
+ <span class="indent">
+ Order Deny,Allow<br />
+ Deny from all<br />
+ Allow from 192.168.0<br />
+ </span>
+ &lt;/Proxy&gt;
+ </code></p></div>
+
+ <p>For more information on access control directives, see
+ <code class="module"><a href="../mod/mod_access.html">mod_access</a></code>.</p>
+
+ <p>Strictly limiting access is essential if you are using a
+ forward proxy (using the <code class="directive"><a href="#proxyrequests">ProxyRequests</a></code> directive).
+ Otherwise, your server can be used by any client to access
+ arbitrary hosts while hiding his or her true identity. This is
+ dangerous both for your network and for the Internet at large.
+ When using a reverse proxy (using the <code class="directive"><a href="#proxypass">ProxyPass</a></code> directive with
+ <code>ProxyRequests Off</code>), access control is less
+ critical because clients can only contact the hosts that you
+ have specifically configured.</p>
+
+ </div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
+<div class="section">
+<h2><a name="ftp-proxy" id="ftp-proxy">FTP Proxy</a></h2>
+
+
+ <h3><a name="mimetypes" id="mimetypes">Why doesn't file type <var>xxx</var>
+ download via FTP?</a></h3>
+ <p>You probably don't have that particular file type defined as
+ <code>application/octet-stream</code> in your proxy's mime.types
+ configuration file. A useful line can be</p>
+
+ <div class="example"><pre>application/octet-stream bin dms lha lzh exe class tgz taz</pre></div>
+
+
+ <h3><a name="type" id="type">How can I force an FTP ASCII download of
+ File <var>xxx</var>?</a></h3>
+ <p>In the rare situation where you must download a specific file using the
+ FTP <code>ASCII</code> transfer method (while the default transfer is in
+ <code>binary</code> mode), you can override <code class="module"><a href="../mod/mod_proxy.html">mod_proxy</a></code>'s
+ default by suffixing the request with <code>;type=a</code> to force an
+ ASCII transfer. (FTP Directory listings are always executed in ASCII mode,
+ however.)</p>
+
+
+ <h3><a name="percent2fhck" id="percent2fhck">How can I access FTP files outside
+ of my home directory?</a></h3>
+ <p>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 <dfn>Squid
+ %2f hack</dfn> was implemented in the Apache FTP proxy; it is a
+ solution which is also used by other popular proxy servers like the <a href="http://www.squid-cache.org/">Squid Proxy Cache</a>. By
+ prepending <code>/%2f</code> to the path of your request, you can make
+ such a proxy change the FTP starting directory to <code>/</code> (instead
+ of the home directory). For example, to retrieve the file
+ <code>/etc/motd</code>, you would use the URL:</p>
+
+ <div class="example"><p><code>
+ ftp://<var>user</var>@<var>host</var>/%2f/etc/motd
+ </code></p></div>
+
+
+ <h3><a name="ftppass" id="ftppass">How can I hide the FTP cleartext password
+ in my browser's URL line?</a></h3>
+ <p>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 anonymous login to the FTP server,
+ <em>i.e.</em>,</p>
+
+ <div class="example"><p><code>
+ user: anonymous<br />
+ password: apache_proxy@
+ </code></p></div>
+
+ <p>This works for all popular FTP servers which are configured for
+ anonymous access.</p>
+
+ <p>For a personal login with a specific username, you can embed the user
+ name into the URL, like in:</p>
+
+ <div class="example"><p><code>
+ ftp://<var>username</var>@<var>host</var>/myfile
+ </code></p></div>
+
+ <p>If the FTP server asks for a password when given this username (which
+ it should), then Apache will reply with a <code>401</code> (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</p>
+
+ <div class="example"><p><code>
+ ftp://<var>username</var>:<var>password</var>@<var>host</var>/myfile
+ </code></p></div>
+
+ <p>in the first place).</p>
+
+ <div class="note"><h3>Note</h3>
+ <p>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.</p>
+ </div>
+
+ </div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
+<div class="section">
+<h2><a name="startup" id="startup">Slow Startup</a></h2>
+ <p>If you're using the <code class="directive"><a href="#proxyblock">ProxyBlock</a></code> 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.</p>
+ </div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
+<div class="section">
+<h2><a name="intranet" id="intranet">Intranet Proxy</a></h2>
+ <p>An Apache proxy server situated in an intranet needs to forward
+ external requests through the company's firewall (for this, configure
+ the <code class="directive"><a href="#proxyremote">ProxyRemote</a></code> directive
+ to forward the respective <var>scheme</var> to the firewall proxy).
+ However, when it has to
+ access resources within the intranet, it can bypass the firewall when
+ accessing hosts. The <code class="directive"><a href="#noproxy">NoProxy</a></code>
+ directive is useful for specifying which hosts belong to the intranet and
+ should be accessed directly.</p>
+
+ <p>Users within an intranet tend to omit the local domain name from their
+ WWW requests, thus requesting "http://somehost/" instead of
+ <code>http://somehost.example.com/</code>. Some commercial proxy servers
+ let them get away with this and simply serve the request, implying a
+ configured local domain. When the <code class="directive"><a href="#proxydomain">ProxyDomain</a></code> directive is used and the server is <a href="#proxyrequests">configured for proxy service</a>, 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.</p>
+ </div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
+<div class="section">
+<h2><a name="envsettings" id="envsettings">Protocol Adjustments</a></h2>
+ <p>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 <code class="directive"><a href="../mod/mod_env.html#setenv">SetEnv</a></code> directive.</p>
+
+ <p>These are the <code>force-proxy-request-1.0</code> and
+ <code>proxy-nokeepalive</code> notes.</p>
+
+ <div class="example"><p><code>
+ &lt;Location /buggyappserver/&gt;<br />
+ <span class="indent">
+ ProxyPass http://buggyappserver:7001/foo/<br />
+ SetEnv force-proxy-request-1.0 1<br />
+ SetEnv proxy-nokeepalive 1<br />
+ </span>
+ &lt;/Location&gt;
+ </code></p></div>
+ </div>
+<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
+<div class="directive-section"><h2><a name="AllowCONNECT" id="AllowCONNECT">AllowCONNECT</a> <a name="allowconnect" id="allowconnect">Directive</a></h2>
+<table class="directive">
+<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Ports that are allowed to <code>CONNECT</code> through the
+proxy</td></tr>
+<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>AllowCONNECT <var>port</var> [<var>port</var>] ...</code></td></tr>
+<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>AllowCONNECT 443 563</code></td></tr>
+<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
+<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
+<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
+</table>
+ <p>The <code class="directive">AllowCONNECT</code> directive specifies a list
+ of port numbers to which the proxy <code>CONNECT</code> method may
+ connect. Today's browsers use this method when a <code>https</code>
+ connection is requested and proxy tunneling over HTTP is in effect.</p>
+
+ <p>By default, only the default https port (<code>443</code>) and the
+ default snews port (<code>563</code>) are enabled. Use the
+ <code class="directive">AllowCONNECT</code> directive to override this default and
+ allow connections to the listed ports only.</p>
+
+ <p>Note that you'll need to have <code class="module"><a href="../mod/mod_proxy_connect.html">mod_proxy_connect</a></code> present
+ in the server in order to get the support for the <code>CONNECT</code> at
+ all.</p>
+
+</div>
+<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
+<div class="directive-section"><h2><a name="NoProxy" id="NoProxy">NoProxy</a> <a name="noproxy" id="noproxy">Directive</a></h2>
+<table class="directive">
+<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Hosts, domains, or networks that will be connected to
+directly</td></tr>
+<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>NoProxy <var>host</var> [<var>host</var>] ...</code></td></tr>
+<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
+<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
+<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
+</table>
+ <p>This directive is only useful for Apache proxy servers within
+ intranets. The <code class="directive">NoProxy</code> 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
+ <code class="directive"><a href="#proxyremote">ProxyRemote</a></code> proxy server(s).</p>
+
+ <div class="example"><h3>Example</h3><p><code>
+ ProxyRemote * http://firewall.mycompany.com:81<br />
+ NoProxy .mycompany.com 192.168.112.0/21
+ </code></p></div>
+
+ <p>The <var>host</var> arguments to the <code class="directive">NoProxy</code>
+ directive are one of the following type list:</p>
+
+ <dl>
+
+ <dt><var><a name="domain" id="domain">Domain</a></var></dt>
+ <dd>
+ <p>A <dfn>Domain</dfn> 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 (<em>i.e.</em>, the suffixes of the hostnames are
+ all ending in <var>Domain</var>).</p>
+
+ <div class="example"><h3>Examples</h3><p><code>
+ .com .apache.org.
+ </code></p></div>
+
+ <p>To distinguish <var>Domain</var>s from <var><a href="#hostname">Hostname</a></var>s (both syntactically and semantically; a DNS domain can
+ have a DNS A record, too!), <var>Domain</var>s are always written with a
+ leading period.</p>
+
+ <div class="note"><h3>Note</h3>
+ <p>Domain name comparisons are done without regard to the case, and
+ <var>Domain</var>s are always assumed to be anchored in the root of the
+ DNS tree, therefore two domains <code>.MyDomain.com</code> and
+ <code>.mydomain.com.</code> (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.</p>
+ </div></dd>
+
+
+ <dt><var><a name="subnet" id="subnet">SubNet</a></var></dt>
+ <dd>
+ <p>A <dfn>SubNet</dfn> 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 <var>SubNet</var>. 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:</p>
+
+ <dl>
+ <dt><code>192.168</code> or <code>192.168.0.0</code></dt>
+ <dd>the subnet 192.168.0.0 with an implied netmask of 16 valid bits
+ (sometimes used in the netmask form <code>255.255.0.0</code>)</dd>
+ <dt><code>192.168.112.0/21</code></dt>
+ <dd>the subnet <code>192.168.112.0/21</code> with a netmask of 21
+ valid bits (also used in the form 255.255.248.0)</dd>
+ </dl>
+
+ <p>As a degenerate case, a <em>SubNet</em> with 32 valid bits is the
+ equivalent to an <var><a href="#ipadr">IPAddr</a></var>, while a <var>SubNet</var> with zero
+ valid bits (<em>e.g.</em>, 0.0.0.0/0) is the same as the constant
+ <var>_Default_</var>, matching any IP address.</p></dd>
+
+
+ <dt><var><a name="ipaddr" id="ipaddr">IPAddr</a></var></dt>
+ <dd>
+ <p>A <dfn>IPAddr</dfn> 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.</p>
+ <div class="example"><h3>Example</h3><p><code>
+ 192.168.123.7
+ </code></p></div>
+
+ <div class="note"><h3>Note</h3>
+ <p>An <var>IPAddr</var> does not need to be resolved by the DNS system, so
+ it can result in more effective apache performance.</p>
+ </div></dd>
+
+
+ <dt><var><a name="hostname" id="hostname">Hostname</a></var></dt>
+ <dd>
+ <p>A <dfn>Hostname</dfn> is a fully qualified DNS domain name which can
+ be resolved to one or more <var><a href="#ipaddr">IPAddrs</a></var> via the
+ DNS domain name service. It represents a logical host (in contrast to
+ <var><a href="#domain">Domain</a></var>s, see above) and must be resolvable
+ to at least one <var><a href="#ipaddr">IPAddr</a></var> (or often to a list
+ of hosts with different <var><a href="#ipaddr">IPAddr</a></var>s).</p>
+
+ <div class="example"><h3>Examples</h3><p><code>
+ prep.ai.mit.edu<br />
+ www.apache.org
+ </code></p></div>
+
+ <div class="note"><h3>Note</h3>
+ <p>In many situations, it is more effective to specify an <var><a href="#ipaddr">IPAddr</a></var> in place of a <var>Hostname</var> 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.</p>
+ <p><var>Hostname</var> comparisons are done without regard to the case,
+ and <var>Hostname</var>s are always assumed to be anchored in the root
+ of the DNS tree, therefore two hosts <code>WWW.MyDomain.com</code>
+ and <code>www.mydomain.com.</code> (note the trailing period) are
+ considered equal.</p>
+ </div></dd>
+ </dl>
+
+<h3>See also</h3>
+<ul>
+<li><a href="../dns-caveats.html">DNS Issues</a></li>
+</ul>
+</div>
+<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
+<div class="directive-section"><h2><a name="Proxy" id="Proxy">&lt;Proxy&gt;</a> <a name="proxy" id="proxy">Directive</a></h2>
+<table class="directive">
+<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Container for directives applied to proxied resources</td></tr>
+<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>&lt;Proxy <var>wildcard-url</var>&gt; ...&lt;/Proxy&gt;</code></td></tr>
+<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
+<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
+<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
+</table>
+ <p>Directives placed in <code class="directive">&lt;Proxy&gt;</code>
+ sections apply only to matching proxied content. Shell-style wildcards are
+ allowed.</p>
+
+ <p>For example, the following will allow only hosts in
+ <code>yournetwork.example.com</code> to access content via your proxy
+ server:</p>
+
+ <div class="example"><p><code>
+ &lt;Proxy *&gt;<br />
+ <span class="indent">
+ Order Deny,Allow<br />
+ Deny from all<br />
+ Allow from yournetwork.example.com<br />
+ </span>
+ &lt;/Proxy&gt;
+ </code></p></div>
+
+ <p>The following example will process all files in the <code>foo</code>
+ directory of <code>example.com</code> through the <code>INCLUDES</code>
+ filter when they are sent through the proxy server:</p>
+
+ <div class="example"><p><code>
+ &lt;Proxy http://example.com/foo/*&gt;<br />
+ <span class="indent">
+ SetOutputFilter INCLUDES<br />
+ </span>
+ &lt;/Proxy&gt;
+ </code></p></div>
+
+</div>
+<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
+<div class="directive-section"><h2><a name="ProxyBadHeader" id="ProxyBadHeader">ProxyBadHeader</a> <a name="proxybadheader" id="proxybadheader">Directive</a></h2>
+<table class="directive">
+<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Determines how to handle bad header lines in a
+response</td></tr>
+<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyBadHeader IsError|Ignore|StartBody</code></td></tr>
+<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ProxyBadHeader IsError</code></td></tr>
+<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
+<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
+<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
+<tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache 2.0.44 and later</td></tr>
+</table>
+ <p>The <code class="directive">ProxyBadHeader</code> directive determines the
+ behaviour of <code class="module"><a href="../mod/mod_proxy.html">mod_proxy</a></code> if it receives syntactically invalid
+ header lines (<em>i.e.</em> containing no colon). The following arguments
+ are possible:</p>
+
+ <dl>
+ <dt><code>IsError</code></dt>
+ <dd>Abort the request and end up with a 502 (Bad Gateway) response. This is
+ the default behaviour.</dd>
+
+ <dt><code>Ignore</code></dt>
+ <dd>Treat bad header lines as if they weren't sent.</dd>
+
+ <dt><code>StartBody</code></dt>
+ <dd>When receiving the first bad header line, finish reading the headers and
+ treat the remainder as body. This helps to work around buggy backend servers
+ which forget to insert an empty line between the headers and the body.</dd>
+ </dl>
+
+</div>
+<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
+<div class="directive-section"><h2><a name="ProxyBlock" id="ProxyBlock">ProxyBlock</a> <a name="proxyblock" id="proxyblock">Directive</a></h2>
+<table class="directive">
+<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Words, hosts, or domains that are banned from being
+proxied</td></tr>
+<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyBlock *|<var>word</var>|<var>host</var>|<var>domain</var>
+[<var>word</var>|<var>host</var>|<var>domain</var>] ...</code></td></tr>
+<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
+<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
+<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
+</table>
+ <p>The <code class="directive">ProxyBlock</code> 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 <em>blocked</em> 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.</p>
+
+ <div class="example"><h3>Example</h3><p><code>
+ ProxyBlock joes-garage.com some-host.co.uk rocky.wotsamattau.edu
+ </code></p></div>
+
+ <p><code>rocky.wotsamattau.edu</code> would also be matched if referenced by
+ IP address.</p>
+
+ <p>Note that <code>wotsamattau</code> would also be sufficient to match
+ <code>wotsamattau.edu</code>.</p>
+
+ <p>Note also that</p>
+
+ <div class="example"><p><code>
+ ProxyBlock *
+ </code></p></div>
+
+ <p>blocks connections to all sites.</p>
+
+</div>
+<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
+<div class="directive-section"><h2><a name="ProxyDomain" id="ProxyDomain">ProxyDomain</a> <a name="proxydomain" id="proxydomain">Directive</a></h2>
+<table class="directive">
+<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Default domain name for proxied requests</td></tr>
+<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyDomain <var>Domain</var></code></td></tr>
+<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
+<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
+<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
+</table>
+ <p>This directive is only useful for Apache proxy servers within
+ intranets. The <code class="directive">ProxyDomain</code> 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 <var>Domain</var> appended
+ will be generated.</p>
+
+ <div class="example"><h3>Example</h3><p><code>
+ ProxyRemote * http://firewall.mycompany.com:81<br />
+ NoProxy .mycompany.com 192.168.112.0/21<br />
+ ProxyDomain .mycompany.com
+ </code></p></div>
+
+</div>
+<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
+<div class="directive-section"><h2><a name="ProxyErrorOverride" id="ProxyErrorOverride">ProxyErrorOverride</a> <a name="proxyerroroverride" id="proxyerroroverride">Directive</a></h2>
+<table class="directive">
+<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Override error pages for proxied content</td></tr>
+<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyErrorOverride On|Off</code></td></tr>
+<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ProxyErrorOverride Off</code></td></tr>
+<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
+<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
+<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
+<tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in version 2.0 and later</td></tr>
+</table>
+ <p>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).</p>
+
+</div>
+<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
+<div class="directive-section"><h2><a name="ProxyFtpDirCharset" id="ProxyFtpDirCharset">ProxyFtpDirCharset</a> <a name="proxyftpdircharset" id="proxyftpdircharset">Directive</a></h2>
+<table class="directive">
+<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Define the character set for proxied FTP listings</td></tr>
+<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyFtpDirCharset <var>character set</var></code></td></tr>
+<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ProxyFtpDirCharset ISO-8859-1</code></td></tr>
+<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory</td></tr>
+<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
+<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
+<tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache 2.0.62 and later</td></tr>
+</table>
+ <p>The <code class="directive">ProxyFtpDirCharset</code> directive defines the
+ character set to be set for FTP directory listings in HTML generated by
+ <code class="module"><a href="../mod/mod_proxy_ftp.html">mod_proxy_ftp</a></code>.</p>
+
+</div>
+<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
+<div class="directive-section"><h2><a name="ProxyIOBufferSize" id="ProxyIOBufferSize">ProxyIOBufferSize</a> <a name="proxyiobuffersize" id="proxyiobuffersize">Directive</a></h2>
+<table class="directive">
+<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Determine size of internal data throughput buffer</td></tr>
+<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyIOBufferSize <var>bytes</var></code></td></tr>
+<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ProxyIOBufferSize 8192</code></td></tr>
+<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
+<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
+<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
+</table>
+ <p>The <code class="directive">ProxyIOBufferSize</code> 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 <code>8192</code>.</p>
+
+ <p>In almost every case there's no reason to change that value.</p>
+
+</div>
+<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
+<div class="directive-section"><h2><a name="ProxyMatch" id="ProxyMatch">&lt;ProxyMatch&gt;</a> <a name="proxymatch" id="proxymatch">Directive</a></h2>
+<table class="directive">
+<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Container for directives applied to regular-expression-matched
+proxied resources</td></tr>
+<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>&lt;ProxyMatch <var>regex</var>&gt; ...&lt;/ProxyMatch&gt;</code></td></tr>
+<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
+<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
+<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
+</table>
+ <p>The <code class="directive">&lt;ProxyMatch&gt;</code> directive is
+ identical to the <code class="directive"><a href="#proxy">&lt;Proxy&gt;</a></code> directive, except it matches URLs
+ using regular expressions.</p>
+
+</div>
+<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
+<div class="directive-section"><h2><a name="ProxyMaxForwards" id="ProxyMaxForwards">ProxyMaxForwards</a> <a name="proxymaxforwards" id="proxymaxforwards">Directive</a></h2>
+<table class="directive">
+<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Maximium number of proxies that a request can be forwarded
+through</td></tr>
+<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyMaxForwards <var>number</var></code></td></tr>
+<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ProxyMaxForwards 10</code></td></tr>
+<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
+<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
+<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
+<tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache 2.0 and later</td></tr>
+</table>
+ <p>The <code class="directive">ProxyMaxForwards</code> directive specifies the
+ maximum number of proxies through which a request may pass, if there's no
+ <code>Max-Forwards</code> header supplied with the request. This is
+ set to prevent infinite proxy loops, or a DoS attack.</p>
+
+ <div class="example"><h3>Example</h3><p><code>
+ ProxyMaxForwards 15
+ </code></p></div>
+
+</div>
+<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
+<div class="directive-section"><h2><a name="ProxyPass" id="ProxyPass">ProxyPass</a> <a name="proxypass" id="proxypass">Directive</a></h2>
+<table class="directive">
+<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Maps remote servers into the local server URL-space</td></tr>
+<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyPass [<var>path</var>] !|<var>url</var></code></td></tr>
+<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory</td></tr>
+<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
+<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
+</table>
+ <p>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. <var>path</var> is the name of a local virtual path; <var>url</var>
+ is a partial URL for the remote server and cannot include a query
+ string.</p>
+
+ <p>Suppose the local server has address <code>http://example.com/</code>;
+ then</p>
+
+ <div class="example"><p><code>
+ ProxyPass /mirror/foo/ http://backend.example.com/
+ </code></p></div>
+
+ <p>will cause a local request for
+ <code>http://example.com/mirror/foo/bar</code> to be internally converted
+ into a proxy request to <code>http://backend.example.com/bar</code>.</p>
+
+ <p>The <code>!</code> directive is useful in situations where you don't want
+ to reverse-proxy a subdirectory, <em>e.g.</em></p>
+
+ <div class="example"><p><code>
+ ProxyPass /mirror/foo/i !<br />
+ ProxyPass /mirror/foo http://backend.example.com
+ </code></p></div>
+
+ <p>will proxy all requests to <code>/mirror/foo</code> to
+ <code>backend.example.com</code> <em>except</em> requests made to
+ <code>/mirror/foo/i</code>.</p>
+
+ <div class="note"><h3>Note</h3>
+ <p>Order is important. you need to put the exclusions <em>before</em> the
+ general proxypass directive.</p>
+ </div>
+
+ <p>When used inside a <code class="directive"><a href="../mod/core.html#location">&lt;Location&gt;</a></code> section, the first argument is omitted and the local
+ directory is obtained from the <code class="directive"><a href="../mod/core.html#location">&lt;Location&gt;</a></code>.</p>
+
+ <div class="warning">The <code class="directive"><a href="#proxyrequests">ProxyRequests</a></code> directive should
+ usually be set <strong>off</strong> when using
+ <code class="directive">ProxyPass</code>.</div>
+
+ <p>If you require a more flexible reverse-proxy configuration, see the
+ <code class="directive"><a href="../mod/mod_rewrite.html#rewriterule">RewriteRule</a></code> directive with the
+ <code>[P]</code> flag.</p>
+
+</div>
+<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
+<div class="directive-section"><h2><a name="ProxyPassReverse" id="ProxyPassReverse">ProxyPassReverse</a> <a name="proxypassreverse" id="proxypassreverse">Directive</a></h2>
+<table class="directive">
+<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Adjusts the URL in HTTP response headers sent from a reverse
+proxied server</td></tr>
+<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyPassReverse [<var>path</var>] <var>url</var></code></td></tr>
+<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory</td></tr>
+<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
+<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
+</table>
+ <p>This directive lets Apache adjust the URL in the <code>Location</code>,
+ <code>Content-Location</code> and <code>URI</code> 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.</p>
+
+ <p>Only the HTTP response headers specifically mentioned above
+ will be rewritten. Apache will not rewrite other response
+ headers, nor will it rewrite URL references inside HTML pages.
+ This means that if the proxied content contains absolute URL
+ references, they will by-pass the proxy. A third-party module
+ that will look inside the HTML and rewrite URL references is Nick
+ Kew's <a href="http://www.webthing.com/software/mod_proxy_html/">mod_proxy_html</a>.</p>
+
+ <p><var>path</var> is the name of a local virtual path. <var>url</var> is a
+ partial URL for the remote server - the same way they are used for the
+ <code class="directive"><a href="#proxypass">ProxyPass</a></code> directive.</p>
+
+ <p>For example, suppose the local server has address
+ <code>http://example.com/</code>; then</p>
+
+ <div class="example"><p><code>
+ ProxyPass /mirror/foo/ http://backend.example.com/<br />
+ ProxyPassReverse /mirror/foo/ http://backend.example.com/
+ </code></p></div>
+
+ <p>will not only cause a local request for the
+ <code>http://example.com/mirror/foo/bar</code> to be internally converted
+ into a proxy request to <code>http://backend.example.com/bar</code>
+ (the functionality <code>ProxyPass</code> provides here). It also takes care
+ of redirects the server <code>backend.example.com</code> sends: when
+ <code>http://backend.example.com/bar</code> is redirected by him to
+ <code>http://backend.example.com/quux</code> Apache adjusts this to
+ <code>http://example.com/mirror/foo/quux</code> 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 <code class="directive"><a href="../mod/core.html#usecanonicalname">UseCanonicalName</a></code> directive.</p>
+
+ <p>Note that this <code class="directive">ProxyPassReverse</code> directive can
+ also be used in conjunction with the proxy pass-through feature
+ (<code>RewriteRule ... [P]</code>) from <code class="module"><a href="../mod/mod_rewrite.html">mod_rewrite</a></code>
+ because its doesn't depend on a corresponding <code class="directive"><a href="#proxypass">ProxyPass</a></code> directive.</p>
+
+ <p>When used inside a <code class="directive"><a href="../mod/core.html#location">&lt;Location&gt;</a></code> section, the first argument is omitted and the local
+ directory is obtained from the <code class="directive"><a href="../mod/core.html#location">&lt;Location&gt;</a></code>.</p>
+
+</div>
+<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
+<div class="directive-section"><h2><a name="ProxyPreserveHost" id="ProxyPreserveHost">ProxyPreserveHost</a> <a name="proxypreservehost" id="proxypreservehost">Directive</a></h2>
+<table class="directive">
+<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Use incoming Host HTTP request header for proxy
+request</td></tr>
+<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyPreserveHost On|Off</code></td></tr>
+<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ProxyPreserveHost Off</code></td></tr>
+<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
+<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
+<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
+<tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache 2.0.31 and later.</td></tr>
+</table>
+ <p>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.</p>
+
+ <p>This option should normally be turned <code>Off</code>. 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.</p>
+
+</div>
+<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
+<div class="directive-section"><h2><a name="ProxyReceiveBufferSize" id="ProxyReceiveBufferSize">ProxyReceiveBufferSize</a> <a name="proxyreceivebuffersize" id="proxyreceivebuffersize">Directive</a></h2>
+<table class="directive">
+<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Network buffer size for proxied HTTP and FTP
+connections</td></tr>
+<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyReceiveBufferSize <var>bytes</var></code></td></tr>
+<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ProxyReceiveBufferSize 0</code></td></tr>
+<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
+<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
+<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
+</table>
+ <p>The <code class="directive">ProxyReceiveBufferSize</code> directive specifies an
+ explicit (TCP/IP) network buffer size for proxied HTTP and FTP connections,
+ for increased throughput. It has to be greater than <code>512</code> or set
+ to <code>0</code> to indicate that the system's default buffer size should
+ be used.</p>
+
+ <div class="example"><h3>Example</h3><p><code>
+ ProxyReceiveBufferSize 2048
+ </code></p></div>
+
+</div>
+<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
+<div class="directive-section"><h2><a name="ProxyRemote" id="ProxyRemote">ProxyRemote</a> <a name="proxyremote" id="proxyremote">Directive</a></h2>
+<table class="directive">
+<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Remote proxy used to handle certain requests</td></tr>
+<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyRemote <var>match</var> <var>remote-server</var></code></td></tr>
+<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
+<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
+<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
+</table>
+ <p>This defines remote proxies to this proxy. <var>match</var> 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 <code>*</code> to indicate
+ the server should be contacted for all requests. <var>remote-server</var> is
+ a partial URL for the remote server. Syntax:</p>
+
+ <div class="example"><p><code>
+ <dfn>remote-server</dfn> =
+ <var>scheme</var>://<var>hostname</var>[:<var>port</var>]
+ </code></p></div>
+
+ <p><var>scheme</var> is effectively the protocol that should be used to
+ communicate with the remote server; only <code>http</code> is supported by
+ this module.</p>
+
+ <div class="example"><h3>Example</h3><p><code>
+ ProxyRemote http://goodguys.com/ http://mirrorguys.com:8000<br />
+ ProxyRemote * http://cleversite.com<br />
+ ProxyRemote ftp http://ftpproxy.mydomain.com:8080
+ </code></p></div>
+
+ <p>In the last example, the proxy will forward FTP requests, encapsulated
+ as yet another HTTP proxy request, to another proxy which can handle
+ them.</p>
+
+ <p>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.</p>
+
+</div>
+<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
+<div class="directive-section"><h2><a name="ProxyRemoteMatch" id="ProxyRemoteMatch">ProxyRemoteMatch</a> <a name="proxyremotematch" id="proxyremotematch">Directive</a></h2>
+<table class="directive">
+<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Remote proxy used to handle requests matched by regular
+expressions</td></tr>
+<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyRemoteMatch <var>regex</var> <var>remote-server</var></code></td></tr>
+<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
+<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
+<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
+</table>
+ <p>The <code class="directive">ProxyRemoteMatch</code> is identical to the
+ <code class="directive"><a href="#proxyremote">ProxyRemote</a></code> directive, except the
+ first argument is a regular expression match against the requested URL.</p>
+
+</div>
+<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
+<div class="directive-section"><h2><a name="ProxyRequests" id="ProxyRequests">ProxyRequests</a> <a name="proxyrequests" id="proxyrequests">Directive</a></h2>
+<table class="directive">
+<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Enables forward (standard) proxy requests</td></tr>
+<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyRequests On|Off</code></td></tr>
+<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ProxyRequests Off</code></td></tr>
+<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
+<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
+<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
+</table>
+ <p>This allows or prevents Apache from functioning as a forward proxy
+ server. (Setting ProxyRequests to <code>Off</code> does not disable use of
+ the <code class="directive"><a href="#proxypass">ProxyPass</a></code> directive.)</p>
+
+ <p>In a typical reverse proxy configuration, this option should be set to
+ <code>Off</code>.</p>
+
+ <p>In order to get the functionality of proxying HTTP or FTP sites, you
+ need also <code class="module"><a href="../mod/mod_proxy_http.html">mod_proxy_http</a></code> or <code class="module"><a href="../mod/mod_proxy_ftp.html">mod_proxy_ftp</a></code>
+ (or both) present in the server.</p>
+
+ <div class="warning"><h3>Warning</h3>
+ <p>Do not enable proxying with <code class="directive"><a href="#proxyrequests">ProxyRequests</a></code> until you have <a href="#access">secured your server</a>. Open proxy servers are dangerous
+ both to your network and to the Internet at large.</p>
+ </div>
+
+</div>
+<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
+<div class="directive-section"><h2><a name="ProxyTimeout" id="ProxyTimeout">ProxyTimeout</a> <a name="proxytimeout" id="proxytimeout">Directive</a></h2>
+<table class="directive">
+<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Network timeout for proxied requests</td></tr>
+<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyTimeout <var>seconds</var></code></td></tr>
+<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ProxyTimeout 300</code></td></tr>
+<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
+<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
+<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
+<tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache 2.0.31 and later</td></tr>
+</table>
+ <p>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.</p>
+
+</div>
+<div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
+<div class="directive-section"><h2><a name="ProxyVia" id="ProxyVia">ProxyVia</a> <a name="proxyvia" id="proxyvia">Directive</a></h2>
+<table class="directive">
+<tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Information provided in the <code>Via</code> HTTP response
+header for proxied requests</td></tr>
+<tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyVia On|Off|Full|Block</code></td></tr>
+<tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ProxyVia Off</code></td></tr>
+<tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
+<tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
+<tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
+</table>
+ <p>This directive controls the use of the <code>Via:</code> HTTP
+ header by the proxy. Its intended use is to control the flow of of
+ proxy requests along a chain of proxy servers. See <a href="http://www.ietf.org/rfc/rfc2616.txt">RFC 2616</a> (HTTP/1.1), section
+ 14.45 for an explanation of <code>Via:</code> header lines.</p>
+
+ <ul>
+ <li>If set to <code>Off</code>, which is the default, no special processing
+ is performed. If a request or reply contains a <code>Via:</code> header,
+ it is passed through unchanged.</li>
+
+ <li>If set to <code>On</code>, each request and reply will get a
+ <code>Via:</code> header line added for the current host.</li>
+
+ <li>If set to <code>Full</code>, each generated <code>Via:</code> header
+ line will additionally have the Apache server version shown as a
+ <code>Via:</code> comment field.</li>
+
+ <li>If set to <code>Block</code>, every proxy request will have all its
+ <code>Via:</code> header lines removed. No new <code>Via:</code> header will
+ be generated.</li>
+ </ul>
+
+</div>
+</div>
+<div class="bottomlang">
+<p><span>Available Languages: </span><a href="../en/mod/mod_proxy.html" title="English">&nbsp;en&nbsp;</a></p>
+</div><div id="footer">
+<p class="apache">Copyright 2009 The Apache Software Foundation.<br />Licensed under the <a href="http://www.apache.org/licenses/LICENSE-2.0">Apache License, Version 2.0</a>.</p>
+<p class="menu"><a href="../mod/">Modules</a> | <a href="../mod/directives.html">Directives</a> | <a href="../faq/">FAQ</a> | <a href="../glossary.html">Glossary</a> | <a href="../sitemap.html">Sitemap</a></p></div>
+</body></html> \ No newline at end of file