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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
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<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta name="generator" content="HTML Tidy, see www.w3.org" />
<title>Apache module mod_proxy</title>
</head>
<!-- Background white, links blue (unvisited), navy (visited), red (active) -->
<body bgcolor="#FFFFFF" text="#000000" link="#0000FF"
vlink="#000080" alink="#FF0000">
<div align="CENTER">
<img src="../images/sub.gif" alt="[APACHE DOCUMENTATION]" />
<h3>Apache HTTP Server Version 1.3</h3>
</div>
<h1 align="CENTER">Apache module mod_proxy</h1>
<p>This module provides for an <strong>HTTP 1.1</strong>
caching proxy server.</p>
<p><a href="module-dict.html#Status"
rel="Help"><strong>Status:</strong></a> Extension<br />
<a href="module-dict.html#SourceFile"
rel="Help"><strong>Source File:</strong></a> mod_proxy.c<br />
<a href="module-dict.html#ModuleIdentifier"
rel="Help"><strong>Module Identifier:</strong></a>
proxy_module<br />
<a href="module-dict.html#Compatibility"
rel="Help"><strong>Compatibility:</strong></a> Available in
Apache 1.1 and later.</p>
<h2>Summary</h2>
This module implements a proxy/cache 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
(as of Apache 1.3.23) <code>HTTP/1.1</code>.
The module can be configured to connect to other proxy modules
for these and other protocols.
<p>This module was experimental in Apache 1.1.x. As of Apache
1.2, mod_proxy stability is <em>greatly</em> improved.</p>
<p><strong>Warning:</strong> Do not enable proxying with <a
href="#proxyrequests">ProxyRequests</a> 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>
<h2>Directives</h2>
<ul>
<li><a href="#proxyrequests">ProxyRequests</a></li>
<li><a href="#proxyremote">ProxyRemote</a></li>
<li><a href="#proxypass">ProxyPass</a></li>
<li><a href="#proxypassreverse">ProxyPassReverse</a></li>
<li><a href="#proxyblock">ProxyBlock</a></li>
<li><a href="#allowconnect">AllowCONNECT</a></li>
<li><a href="#proxyreceivebuffersize">ProxyReceiveBufferSize</a></li>
<li><a href="#proxyiobuffersize">ProxyIOBufferSize</a></li>
<li><a href="#noproxy">NoProxy</a></li>
<li><a href="#proxydomain">ProxyDomain</a></li>
<li><a href="#proxyvia">ProxyVia</a></li>
<li><a href="#cacheroot">CacheRoot</a></li>
<li><a href="#cachesize">CacheSize</a></li>
<li><a href="#cachemaxexpire">CacheMaxExpire</a></li>
<li><a href="#cachedefaultexpire">CacheDefaultExpire</a></li>
<li><a
href="#cachelastmodifiedfactor">CacheLastModifiedFactor</a></li>
<li><a href="#cachegcinterval">CacheGcInterval</a></li>
<li><a href="#cachedirlevels">CacheDirLevels</a></li>
<li><a href="#cachedirlength">CacheDirLength</a></li>
<li><a
href="#cacheforcecompletion">CacheForceCompletion</a></li>
<li><a href="#nocache">NoCache</a></li>
</ul>
<h2><a id="configs" name="configs">Common configuration
topics</a></h2>
<ul>
<li><a href="#forwardreverse">Forward and Reverse Proxies</a></li>
<li><a href="#examples">Basic Examples</a></li>
<li><a href="#access">Controlling access to your
proxy</a></li>
<li><a href="#shortname">Using Netscape hostname
shortcuts</a></li>
<li><a href="#mimetypes">Why doesn't file type <em>xxx</em>
download via FTP?</a></li>
<li><a href="#type">How can I force an FTP ASCII
download of File <em>xxx</em>?</a></li>
<li><a href="#percent2fhack">How can I access
FTP files outside of my home directory?</a></li>
<li><a href="#ftppass">How can I hide the
FTP cleartext password in my browser's URL line?</a></li>
<li><a href="#startup">Why does Apache start more slowly when
using the proxy module?</a></li>
<li><a href="#socks">Can I use the Apache proxy module with
my SOCKS proxy?</a></li>
<li><a href="#intranet">What other functions are useful for
an intranet proxy server?</a></li>
</ul>
<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 to reduce
network usage.</p>
<p>The forward proxy is activated using the <code><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><a
href="#proxypass">ProxyPass</a></code> directive or the
<code>[P]</code> flag to the <code><a
href="../mod/mod_rewrite.html#rewriterule">RewriteRule</a></code>
directive. It is <strong>not</strong> necessary to turn
<code><a href="#proxyrequests">ProxyRequests</a></code> on in
order to configure a reverse proxy.</p>
<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>
<h3>Forward Proxy</h3><p><code>
ProxyRequests On<br />
ProxyVia On<br />
<br />
<Directory proxy:*><br />
Order deny,allow<br />
Deny from all<br />
Allow from internal.example.com<br />
</Directory><br />
<br />
CacheRoot "/usr/local/apache/proxy"<br />
CacheSize 5<br />
CacheGcInterval 4<br />
CacheMaxExpire 24<br />
CacheLastModifiedFactor 0.1<br />
CacheDefaultExpire 1<br />
NoCache a-domain.com another-domain.edu joes.garage-sale.com
</code></p>
<h3>Reverse Proxy</h3><p><code>
ProxyRequests Off<br />
<br />
ProxyPass /foo http://foo.example.com/bar<br />
ProxyPassReverse /foo http://foo.example.com/bar
</code></p>
<h2><a id="access" name="access">Controlling access to your
proxy</a></h2>
You can control who can access your proxy via the normal
<Directory> control block using the following example:
<pre>
<Directory proxy:*>
Order Deny,Allow
Deny from all
Allow from yournetwork.example.com
</Directory>
</pre>
<p>A <Files> block will also work, and is the only method
known to work for all possible URLs in Apache versions earlier
than 1.2b10.</p>
<p>For more information, see <a
href="mod_access.html">mod_access</a>.</p>
<p>Strictly limiting access is essential if you are using a
forward proxy (using the <code><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><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>
<h2><a id="shortname" name="shortname">Using Netscape hostname
shortcuts</a></h2>
There is an optional patch to the proxy module to allow
Netscape-like hostname shortcuts to be used. It's available
from the <a
href="http://www.apache.org/dist/httpd/contrib/patches/1.2/netscapehost.patch">
<samp>contrib/patches/1.2</samp></a> directory on the Apache
Web site.
<h2><a id="mimetypes" name="mimetypes">Why doesn't file type
<em>xxx</em> download via FTP?</a></h2>
You probably don't have that particular file type defined as
<em>application/octet-stream</em> in your proxy's mime.types
configuration file. A useful line can be
<pre>
application/octet-stream bin dms lha lzh exe class tgz taz
</pre>
<h2><a id="type" name="type">How can I force an FTP ASCII
download of File <em>xxx</em>?</a></h2>
In the rare situation where you must download a specific file
using the FTP <strong>ASCII</strong> transfer method (while the
default transfer is in <strong>binary</strong> mode), you can
override mod_proxy's default by suffixing the request with
<samp>;type=a</samp> to force an ASCII transfer.
(FTP Directory listings are always executed in ASCII mode, however.)
<h2><a id="percent2fhack" name="percent2fhack">How can I access
FTP files outside of my home directory?</a></h2>
<p>
A 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
<a href="http://www.squid-cache.org/">Squid Proxy Cache</a>.
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). <br />
<b>Example:</b> To retrieve the file <code>/etc/motd</code>,
you would use the URL <blockquote>
<code>ftp://<em>user@host</em>/%2f/etc/motd</code></blockquote>
</p>
<h2><a id="ftppass" name="ftppass">How can I hide the FTP
cleartext password in my browser's URL line?</a></h2>
<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, i.e.,
<blockquote><code>
user: anonymous<br />
password: apache_proxy@
</code></blockquote>
This works for all popular FTP servers which are configured for
anonymous access.<br>
For a personal login with a specific username, you can embed
the user name into the URL, like in:
<code>ftp://<em>username@host</em>/myfile</code>. 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
<code>ftp://<em>username:password@host</em>/myfile</code> in
the first place).
<br />
<b>Note</b> that 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>
<h2><a id="startup" name="startup">Why does Apache start more
slowly when using the proxy module?</a></h2>
If you're using the <code>ProxyBlock</code> or
<code>NoCache</code> directives, 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.
<h2><a id="socks" name="socks">Can I use the Apache proxy
module with my SOCKS proxy?</a></h2>
Yes. Just build Apache with the rule <code>SOCKS4=yes</code> in
your <em>Configuration</em> file, and follow the instructions
there. SOCKS5 capability can be added in a similar way (there's
no <code>SOCKS5</code> rule yet), so use the
<code>EXTRA_LDFLAGS</code> definition, or build Apache normally
and run it with the <em>runsocks</em> wrapper provided with
SOCKS5, if your OS supports dynamically linked libraries.
<p>Some users have reported problems when using SOCKS version
4.2 on Solaris. The problem was solved by upgrading to SOCKS
4.3.</p>
<p>Remember that you'll also have to grant access to your
Apache proxy machine by permitting connections on the
appropriate ports in your SOCKS daemon's configuration.</p>
<h2><a id="intranet" name="intranet">What other functions are
useful for an intranet proxy server?</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 <a href="#proxyremote">ProxyRemote</a>
directive to forward the respective <em>scheme</em> to
the firewall proxy).
However, when it has to access resources within the intranet,
it can bypass the firewall when accessing hosts. The <a
href="#noproxy">NoProxy</a> 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 "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 <a
href="#proxydomain">ProxyDomain</a> 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>
<hr />
<h2><a id="proxyrequests"
name="proxyrequests">ProxyRequests</a> directive</h2>
<a href="directive-dict.html#Syntax"
rel="Help"><strong>Syntax:</strong></a> ProxyRequests
on|off<br />
<a href="directive-dict.html#Default"
rel="Help"><strong>Default:</strong></a> <code>ProxyRequests
Off</code><br />
<a href="directive-dict.html#Context"
rel="Help"><strong>Context:</strong></a> server config, virtual
host<br />
<a href="directive-dict.html#Override"
rel="Help"><strong>Override:</strong></a> <em>Not
applicable</em><br />
<a href="directive-dict.html#Status"
rel="Help"><strong>Status:</strong></a> Base<br />
<a href="directive-dict.html#Module"
rel="Help"><strong>Module:</strong></a> mod_proxy<br />
<a href="directive-dict.html#Compatibility"
rel="Help"><strong>Compatibility:</strong></a> ProxyRequests is
only available in Apache 1.1 and later.
<p>This allows or prevents Apache from functioning as a forward proxy
server. Setting ProxyRequests to 'off' does not disable use of
the <a href="#proxypass">ProxyPass</a> directive.</p>
<p><strong>Warning:</strong> Do not enable proxying 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>
<hr />
<h2><a id="proxyremote" name="proxyremote">ProxyRemote</a>
directive</h2>
<a href="directive-dict.html#Syntax"
rel="Help"><strong>Syntax:</strong></a> ProxyRemote <em>match
remote-server</em><br />
<a href="directive-dict.html#Default"
rel="Help"><strong>Default:</strong></a> <em>None</em><br />
<a href="directive-dict.html#Context"
rel="Help"><strong>Context:</strong></a> server config, virtual
host<br />
<a href="directive-dict.html#Override"
rel="Help"><strong>Override:</strong></a> <em>Not
applicable</em><br />
<a href="directive-dict.html#Status"
rel="Help"><strong>Status:</strong></a> Base<br />
<a href="directive-dict.html#Module"
rel="Help"><strong>Module:</strong></a> mod_proxy<br />
<a href="directive-dict.html#Compatibility"
rel="Help"><strong>Compatibility:</strong></a> ProxyRemote is
only available in Apache 1.1 and later.
<p>This defines remote proxies to this proxy. <em>match</em> 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. <em>remote-server</em> is a partial URL for the
remote server. Syntax:</p>
<pre>
remote-server = protocol://hostname[:port]
</pre>
<em>protocol</em> is the protocol that should be used to
communicate with the remote server; only "http" is supported by
this module.
<p>Example:</p>
<pre>
ProxyRemote http://goodguys.com/ http://mirrorguys.com:8000
ProxyRemote * http://cleversite.com
ProxyRemote ftp http://ftpproxy.mydomain.com:8080
</pre>
In the last example, the proxy will forward FTP requests,
encapsulated as yet another HTTP proxy request, to another
proxy which can handle them.
<hr />
<h2><a id="proxypass" name="proxypass">ProxyPass</a>
directive</h2>
<a href="directive-dict.html#Syntax"
rel="Help"><strong>Syntax:</strong></a> ProxyPass <em>path
url</em><br />
<a href="directive-dict.html#Default"
rel="Help"><strong>Default:</strong></a> <em>None</em><br />
<a href="directive-dict.html#Context"
rel="Help"><strong>Context:</strong></a> server config, virtual
host<br />
<a href="directive-dict.html#Override"
rel="Help"><strong>Override:</strong></a> <em>Not
applicable</em><br />
<a href="directive-dict.html#Status"
rel="Help"><strong>Status:</strong></a> Base<br />
<a href="directive-dict.html#Module"
rel="Help"><strong>Module:</strong></a> mod_proxy<br />
<a href="directive-dict.html#Compatibility"
rel="Help"><strong>Compatibility:</strong></a> ProxyPass is
only available in Apache 1.1 and later.
<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. <em>path</em> is the name of a local virtual
path; <em>url</em> is a partial URL for the remote server.</p>
<p>Suppose the local server has address
<samp>http://wibble.org/</samp>; then</p>
<pre>
ProxyPass /mirror/foo/ http://foo.com/
</pre>
<p>will cause a local request for the
<<samp>http://wibble.org/mirror/foo/bar</samp>> to be
internally converted into a proxy request to
<<samp>http://foo.com/bar</samp>>.</p>
<p><strong>Warning:</strong> The <code><a
href="#proxyrequests">ProxyRequests</a></code> directive should
usually be set <strong>off</strong> when using <code
class="directive">ProxyPass</code>.
<hr />
<h2><a id="proxypassreverse"
name="proxypassreverse">ProxyPassReverse</a> directive</h2>
<a href="directive-dict.html#Syntax"
rel="Help"><strong>Syntax:</strong></a> ProxyPassReverse
<em>path url</em><br />
<a href="directive-dict.html#Default"
rel="Help"><strong>Default:</strong></a> <em>None</em><br />
<a href="directive-dict.html#Context"
rel="Help"><strong>Context:</strong></a> server config, virtual
host<br />
<a href="directive-dict.html#Override"
rel="Help"><strong>Override:</strong></a> <em>Not
applicable</em><br />
<a href="directive-dict.html#Status"
rel="Help"><strong>Status:</strong></a> Base<br />
<a href="directive-dict.html#Module"
rel="Help"><strong>Module:</strong></a> mod_proxy<br />
<a href="directive-dict.html#Compatibility"
rel="Help"><strong>Compatibility:</strong></a> ProxyPassReverse
is only available in Apache 1.3b6 and later.
<p>This directive lets Apache adjust the URL in the
<tt>Location</tt> header on HTTP redirect responses. For
instance 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><em>path</em> is the name of a local virtual path.<br />
<em>url</em> is a partial URL for the remote server - the same
way they are used for the <tt>ProxyPass</tt> directive.</p>
<p>Example:<br />
Suppose the local server has address
<samp>http://wibble.org/</samp>; then</p>
<pre>
ProxyPass /mirror/foo/ http://foo.com/
ProxyPassReverse /mirror/foo/ http://foo.com/
</pre>
will not only cause a local request for the
<<samp>http://wibble.org/mirror/foo/bar</samp>> to be
internally converted into a proxy request to
<<samp>http://foo.com/bar</samp>> (the functionality
<samp>ProxyPass</samp> provides here). It also takes care of
redirects the server foo.com sends: when
<samp>http://foo.com/bar</samp> is redirected by him to
<samp>http://foo.com/quux</samp> Apache adjusts this to
<samp>http://wibble.org/mirror/foo/quux</samp> before
forwarding the HTTP redirect response to the client.
<p>Note that this <samp>ProxyPassReverse</samp> directive can
also be used in conjunction with the proxy pass-through feature
("<samp>RewriteRule ... [P]</samp>") from <a
href="mod_rewrite.html#RewriteRule"><tt>mod_rewrite</tt></a>
because its doesn't depend on a corresponding
<samp>ProxyPass</samp> directive.</p>
<hr />
<h2><a id="allowconnect" name="allowconnect">AllowCONNECT</a>
directive</h2>
<a href="directive-dict.html#Syntax"
rel="Help"><strong>Syntax:</strong></a> AllowCONNECT
<em>port</em> [<em>port</em>] ...<br />
<a href="directive-dict.html#Default"
rel="Help"><strong>Default:</strong></a>
<em><samp>AllowCONNECT</samp> 443 563</em><br />
<a href="directive-dict.html#Context"
rel="Help"><strong>Context:</strong></a> server config, virtual
host<br />
<a href="directive-dict.html#Override"
rel="Help"><strong>Override:</strong></a> <em>Not
applicable</em><br />
<a href="directive-dict.html#Status"
rel="Help"><strong>Status:</strong></a> Base<br />
<a href="directive-dict.html#Module"
rel="Help"><strong>Module:</strong></a> mod_proxy<br />
<a href="directive-dict.html#Compatibility"
rel="Help"><strong>Compatibility:</strong></a>
<samp>AllowCONNECT</samp> is only available in Apache 1.3.2 and
later.
<p>The <samp>AllowCONNECT</samp> directive specifies a list of
port numbers to which the proxy <samp>CONNECT</samp> method may
connect. Today's browsers use this method when a <em>https</em>
connection is requested and proxy tunneling over <em>http</em>
is in effect.<br />
By default, only the default https port (443) and the default
snews port (563) are enabled. Use the <samp>AllowCONNECT</samp>
directive to override this default and allow connections to
the listed ports only.</p>
<hr />
<h2><a id="proxyblock" name="proxyblock">ProxyBlock</a>
directive</h2>
<a href="directive-dict.html#Syntax"
rel="Help"><strong>Syntax:</strong></a> ProxyBlock
*|<em>word|host|domain</em> [<em>word|host|domain</em>]
...<br />
<a href="directive-dict.html#Default"
rel="Help"><strong>Default:</strong></a> <em>None</em><br />
<a href="directive-dict.html#Context"
rel="Help"><strong>Context:</strong></a> server config, virtual
host<br />
<a href="directive-dict.html#Override"
rel="Help"><strong>Override:</strong></a> <em>Not
applicable</em><br />
<a href="directive-dict.html#Status"
rel="Help"><strong>Status:</strong></a> Base<br />
<a href="directive-dict.html#Module"
rel="Help"><strong>Module:</strong></a> mod_proxy<br />
<a href="directive-dict.html#Compatibility"
rel="Help"><strong>Compatibility:</strong></a> ProxyBlock is
only available in Apache 1.2 and later.
<p>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 <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. Example:</p>
<pre>
ProxyBlock joes-garage.com some-host.co.uk rocky.wotsamattau.edu
</pre>
'rocky.wotsamattau.edu' would also be matched if referenced by
IP address.
<p>Note that 'wotsamattau' would also be sufficient to match
'wotsamattau.edu'.</p>
<p>Note also that</p>
<pre>
ProxyBlock *
</pre>
blocks connections to all sites.
<hr />
<h2><a id="proxyreceivebuffersize"
name="proxyreceivebuffersize">ProxyReceiveBufferSize</a>
directive</h2>
<a href="directive-dict.html#Syntax"
rel="Help"><strong>Syntax:</strong></a> ProxyReceiveBufferSize
<em>bytes</em><br />
<a href="directive-dict.html#Default"
rel="Help"><strong>Default:</strong></a> <em>None</em><br />
<a href="directive-dict.html#Context"
rel="Help"><strong>Context:</strong></a> server config, virtual
host<br />
<a href="directive-dict.html#Override"
rel="Help"><strong>Override:</strong></a> <em>Not
applicable</em><br />
<a href="directive-dict.html#Status"
rel="Help"><strong>Status:</strong></a> Base<br />
<a href="directive-dict.html#Module"
rel="Help"><strong>Module:</strong></a> mod_proxy<br />
<a href="directive-dict.html#Compatibility"
rel="Help"><strong>Compatibility:</strong></a>
ProxyReceiveBufferSize is only available in Apache 1.3 and
later.
<p>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.</p>
<p>Example:</p>
<pre>
ProxyReceiveBufferSize 2048
</pre>
<hr />
<h2><a id="proxyiobuffersize"
name="proxyiobuffersize">ProxyIOBufferSize</a>
directive</h2>
<a href="directive-dict.html#Syntax"
rel="Help"><strong>Syntax:</strong></a> ProxyIOBufferSize
<em>bytes</em><br />
<a href="directive-dict.html#Default"
rel="Help"><strong>Default:</strong></a> <em>8192</em><br />
<a href="directive-dict.html#Context"
rel="Help"><strong>Context:</strong></a> server config, virtual
host<br />
<a href="directive-dict.html#Override"
rel="Help"><strong>Override:</strong></a> <em>Not
applicable</em><br />
<a href="directive-dict.html#Status"
rel="Help"><strong>Status:</strong></a> Base<br />
<a href="directive-dict.html#Module"
rel="Help"><strong>Module:</strong></a> mod_proxy<br />
<a href="directive-dict.html#Compatibility"
rel="Help"><strong>Compatibility:</strong></a>
ProxyIOBufferSize is only available in Apache 1.3.24 and
later.
<p>The ProxyIOBufferSize directive specifies the number of bytes
that will be read from a remote HTTP or FTP server at one time.
This directive is different from the ProxyReceiveBufferSize
directive, which specifies the low level socket buffer size.
</p>
<p>
When a response is received which fits entirely within the IO
buffer size, the remote HTTP or FTP server socket will be closed
before an attempt is made to write the response to the client.
This ensures that the remote server does not remain connected
unnecessarily while the response is delivered to a slow client.
A high value for the IO buffer decreases the load on remote HTTP
and FTP servers, at the expense of greater RAM footprint on the
proxy.
</p>
<p>Example:</p>
<pre>
ProxyIOBufferSize 131072
</pre>
<hr />
<h2><a id="noproxy" name="noproxy">NoProxy</a> directive</h2>
<a href="directive-dict.html#Syntax"
rel="Help"><strong>Syntax:</strong></a> NoProxy <a
href="#domain"><em>Domain</em></a>|<a
href="#subnet"><em>SubNet</em></a>|<a
href="#ipaddr"><em>IpAddr</em></a>|<a
href="#hostname"><em>Hostname</em></a> [<a
href="#domain"><em>Domain</em></a>|<a
href="#subnet"><em>SubNet</em></a>|<a
href="#ipaddr"><em>IpAddr</em></a>|<a
href="#hostname"><em>Hostname</em></a>] ...<br />
<a href="directive-dict.html#Default"
rel="Help"><strong>Default:</strong></a> <em>None</em><br />
<a href="directive-dict.html#Context"
rel="Help"><strong>Context:</strong></a> server config, virtual
host<br />
<a href="directive-dict.html#Override"
rel="Help"><strong>Override:</strong></a> <em>Not
applicable</em><br />
<a href="directive-dict.html#Status"
rel="Help"><strong>Status:</strong></a> Base<br />
<a href="directive-dict.html#Module"
rel="Help"><strong>Module:</strong></a> mod_proxy<br />
<a href="directive-dict.html#Compatibility"
rel="Help"><strong>Compatibility:</strong></a> NoProxy is only
available in Apache 1.3 and later.
<p>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).</p>
<p>Example:</p>
<pre>
ProxyRemote * http://firewall.mycompany.com:81
NoProxy .mycompany.com 192.168.112.0/21
</pre>
The arguments to the NoProxy directive are one of the following
type list:
<dl>
<!-- ===================== Domain ======================= -->
<dt><a id="domain" name="domain"><em>Domain</em></a></dt>
<dd>A <em>Domain</em> 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 <em>Domain</em>).<br />
Examples: <samp>.com</samp> <samp>.apache.org.</samp><br />
To distinguish <em>Domain</em>s from <a
href="#hostname"><em>Hostname</em></a>s (both syntactically
and semantically; a DNS domain can have a DNS A record,
too!), <em>Domain</em>s are always written with a leading
period.<br />
Note: Domain name comparisons are done without regard to the
case, and <em>Domain</em>s are always assumed to be anchored
in the root of the DNS tree, therefore two domains
<samp>.MyDomain.com</samp> and <samp>.mydomain.com.</samp>
(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.
<!-- ===================== SubNet ======================= -->
</dd>
<dt><a id="subnet" name="subnet"><em>SubNet</em></a></dt>
<dd>
A <em>SubNet</em> 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 <em>SubNet</em>. 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.)<br />
Examples:
<dl>
<dt><samp>192.168</samp> or <samp>192.168.0.0</samp></dt>
<dd>the subnet 192.168.0.0 with an implied netmask of 16
valid bits (sometimes used in the netmask form
<samp>255.255.0.0</samp>)</dd>
<dt><samp>192.168.112.0/21</samp></dt>
<dd>the subnet <samp>192.168.112.0/21</samp> with a
netmask of 21 valid bits (also used in the form
255.255.248.0)</dd>
</dl>
As a degenerate case, a <em>SubNet</em> with 32 valid bits
is the equivalent to an <em>IPAddr</em>, while a
<em>SubNet</em> with zero valid bits (<em>e.g.</em>,
0.0.0.0/0) is the same as the constant <em>_Default_</em>,
matching any IP address.
<!-- ===================== IPAddr ======================= -->
</dd>
<dt><a id="ipaddr" name="ipaddr"><em>IPAddr</em></a></dt>
<dd>
A <em>IPAddr</em> 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.<br />
Example: 192.168.123.7<br />
Note: An <em>IPAddr</em> does not need to be resolved by
the DNS system, so it can result in more effective apache
performance.
<p><strong>See Also:</strong> <a
href="../dns-caveats.html">DNS Issues</a></p>
<!-- ===================== Hostname ======================= -->
</dd>
<dt><a id="hostname"
name="hostname"><em>Hostname</em></a></dt>
<dd>
A <em>Hostname</em> is a fully qualified DNS domain name
which can be resolved to one or more <a
href="#ipaddr"><em>IPAddrs</em></a> via the DNS domain name
service. It represents a logical host (in contrast to <a
href="#domain"><em>Domain</em></a>s, see above) and must be
resolvable to at least one <a
href="#ipaddr"><em>IPAddr</em></a> (or often to a list of
hosts with different <a
href="#ipaddr"><em>IPAddr</em></a>'s).<br />
Examples: <samp>prep.ai.mit.edu</samp>
<samp>www.apache.org.</samp><br />
Note: In many situations, it is more effective to specify
an <a href="#ipaddr"><em>IPAddr</em></a> in place of a
<em>Hostname</em> 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.<br />
Note: <em>Hostname</em> comparisons are done without
regard to the case, and <em>Hostname</em>s are always
assumed to be anchored in the root of the DNS tree,
therefore two hosts <samp>WWW.MyDomain.com</samp> and
<samp>www.mydomain.com.</samp> (note the trailing period)
are considered equal.<br />
<p><strong>See Also:</strong> <a
href="../dns-caveats.html">DNS Issues</a></p>
</dd>
</dl>
<hr />
<h2><a id="proxydomain" name="proxydomain">ProxyDomain</a>
directive</h2>
<a href="directive-dict.html#Syntax"
rel="Help"><strong>Syntax:</strong></a> ProxyDomain
<em>Domain</em><br />
<a href="directive-dict.html#Default"
rel="Help"><strong>Default:</strong></a> <em>None</em><br />
<a href="directive-dict.html#Context"
rel="Help"><strong>Context:</strong></a> server config, virtual
host<br />
<a href="directive-dict.html#Override"
rel="Help"><strong>Override:</strong></a> <em>Not
applicable</em><br />
<a href="directive-dict.html#Status"
rel="Help"><strong>Status:</strong></a> Base<br />
<a href="directive-dict.html#Module"
rel="Help"><strong>Module:</strong></a> mod_proxy<br />
<a href="directive-dict.html#Compatibility"
rel="Help"><strong>Compatibility:</strong></a> ProxyDomain is
only available in Apache 1.3 and later.
<p>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
<em>Domain</em> appended will be generated.</p>
<p>Example:</p>
<pre>
ProxyRemote * http://firewall.mycompany.com:81
NoProxy .mycompany.com 192.168.112.0/21
ProxyDomain .mycompany.com
</pre>
<hr />
<h2><a id="proxyvia" name="proxyvia">ProxyVia</a>
directive</h2>
<a href="directive-dict.html#Syntax"
rel="Help"><strong>Syntax:</strong></a> ProxyVia
on|off|full|block<br />
<a href="directive-dict.html#Default"
rel="Help"><strong>Default:</strong></a> <em>ProxyVia
off</em><br />
<a href="directive-dict.html#Context"
rel="Help"><strong>Context:</strong></a> server config, virtual
host<br />
<a href="directive-dict.html#Override"
rel="Help"><strong>Override:</strong></a> <em>Not
applicable</em><br />
<a href="directive-dict.html#Status"
rel="Help"><strong>Status:</strong></a> Base<br />
<a href="directive-dict.html#Module"
rel="Help"><strong>Module:</strong></a> mod_proxy<br />
<a href="directive-dict.html#Compatibility"
rel="Help"><strong>Compatibility:</strong></a> ProxyVia is only
available in Apache 1.3.2 and later.
<p>This directive controls the use of the <samp>Via:</samp>
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 <samp>Via:</samp>
header lines.</p>
<ul>
<li>If set to <em>off</em>, which is the default, no special
processing is performed. If a request or reply contains a
<samp>Via:</samp> header, it is passed through
unchanged.</li>
<li>If set to <em>on</em>, each request and reply will get a
<samp>Via:</samp> header line added for the current
host.</li>
<li>If set to <em>full</em>, each generated <samp>Via:</samp>
header line will additionally have the Apache server version
shown as a <samp>Via:</samp> comment field.</li>
<li>If set to <em>block</em>, every proxy request will have
all its <samp>Via:</samp> header lines removed. No new
<samp>Via:</samp> header will be generated.</li>
</ul>
<hr />
<h2><a id="cacheforcecompletion"
name="cacheforcecompletion">CacheForceCompletion</a>
directive</h2>
<a href="directive-dict.html#Syntax"
rel="Help"><strong>Syntax:</strong></a> CacheForceCompletion
<em>percentage</em><br />
<a href="directive-dict.html#Default"
rel="Help"><strong>Default:</strong></a> <em>90</em><br />
<a href="directive-dict.html#Context"
rel="Help"><strong>Context:</strong></a> server config, virtual
host<br />
<a href="directive-dict.html#Override"
rel="Help"><strong>Override:</strong></a> <em>Not
applicable</em><br />
<a href="directive-dict.html#Status"
rel="Help"><strong>Status:</strong></a> Base<br />
<a href="directive-dict.html#Module"
rel="Help"><strong>Module:</strong></a> mod_proxy<br />
<a href="directive-dict.html#Compatibility"
rel="Help"><strong>Compatibility:</strong></a>
CacheForceCompletion is only available in Apache 1.3.1 and
later.
<p>If an http transfer that is being cached is cancelled, the
proxy module will complete the transfer to cache if more than
the percentage specified has already been transferred.</p>
<p>This is a percentage, and must be a number between 1 and
100, or 0 to use the default. 100 will cause a document to be
cached only if the transfer was allowed to complete. A number
between 60 and 90 is recommended.</p>
<hr />
<h2><a id="cacheroot" name="cacheroot">CacheRoot</a>
directive</h2>
<a href="directive-dict.html#Syntax"
rel="Help"><strong>Syntax:</strong></a> CacheRoot
<em>directory</em><br />
<a href="directive-dict.html#Default"
rel="Help"><strong>Default:</strong></a> <em>None</em><br />
<a href="directive-dict.html#Context"
rel="Help"><strong>Context:</strong></a> server config, virtual
host<br />
<a href="directive-dict.html#Override"
rel="Help"><strong>Override:</strong></a> <em>Not
applicable</em><br />
<a href="directive-dict.html#Status"
rel="Help"><strong>Status:</strong></a> Base<br />
<a href="directive-dict.html#Module"
rel="Help"><strong>Module:</strong></a> mod_proxy<br />
<a href="directive-dict.html#Compatibility"
rel="Help"><strong>Compatibility:</strong></a> CacheRoot is
only available in Apache 1.1 and later.
<p>Sets the name of the directory to contain cache files; this
must be writable by the httpd server. (see the <a
href="core.html#user"><code>User</code></a> directive).<br />
Setting <code>CacheRoot</code> enables proxy cacheing; without
defining a <code>CacheRoot</code>, proxy functionality will be
available if <code>ProxyRequests</code> are set to
<code>On</code>, but no cacheing will be available.</p>
<hr />
<h2><a id="cachesize" name="cachesize">CacheSize</a>
directive</h2>
<a href="directive-dict.html#Syntax"
rel="Help"><strong>Syntax:</strong></a> CacheSize
<em>kilobytes</em><br />
<a href="directive-dict.html#Default"
rel="Help"><strong>Default:</strong></a> <code>CacheSize
5</code><br />
<a href="directive-dict.html#Context"
rel="Help"><strong>Context:</strong></a> server config, virtual
host<br />
<a href="directive-dict.html#Override"
rel="Help"><strong>Override:</strong></a> <em>Not
applicable</em><br />
<a href="directive-dict.html#Status"
rel="Help"><strong>Status:</strong></a> Base<br />
<a href="directive-dict.html#Module"
rel="Help"><strong>Module:</strong></a> mod_proxy<br />
<a href="directive-dict.html#Compatibility"
rel="Help"><strong>Compatibility:</strong></a> CacheSize is
only available in Apache 1.1 and later.
<p>Sets the desired space usage of the cache, in KB (1024-byte
units). Although usage may grow above this setting, the garbage
collection will delete files until the usage is at or below
this setting.<br />
Depending on the expected proxy traffic volume and
<code>CacheGcInterval</code>, use a value which is at least 20
to 40 % lower than the available space.</p>
<hr />
<h2><a id="cachegcinterval"
name="cachegcinterval">CacheGcInterval</a> directive</h2>
<a href="directive-dict.html#Syntax"
rel="Help"><strong>Syntax:</strong></a> CacheGcInterval
<em>hours</em><br />
<a href="directive-dict.html#Default"
rel="Help"><strong>Default:</strong></a> <em>None</em><br />
<a href="directive-dict.html#Context"
rel="Help"><strong>Context:</strong></a> server config, virtual
host<br />
<a href="directive-dict.html#Override"
rel="Help"><strong>Override:</strong></a> <em>Not
applicable</em><br />
<a href="directive-dict.html#Status"
rel="Help"><strong>Status:</strong></a> Base<br />
<a href="directive-dict.html#Module"
rel="Help"><strong>Module:</strong></a> mod_proxy<br />
<a href="directive-dict.html#Compatibility"
rel="Help"><strong>Compatibility:</strong></a> CacheGcinterval
is only available in Apache 1.1 and later.
<p>Check the cache after the specified number of
<em>hours</em>, and delete files if the space usage is greater
than that set by CacheSize. Note that <em>hours</em> accepts a
float value, you could for example use <code>CacheGcInterval
1.5</code> to check the cache every 90 minutes. (If unset, no
garbage collection will be performed, and the cache will grow
indefinitely.) Note also that the larger the
<code>CacheGcInterval</code>, the more extra space beyond the
configured <code>CacheSize</code> will be needed for the cache
between garbage collections.<br />
<!-- Note that due to a design flaw, Apache
does not automatically force a garbage collection when the available
space on the file system where the cache resides is exhausted. -->
</p>
<hr />
<h2><a id="cachemaxexpire"
name="cachemaxexpire">CacheMaxExpire</a> directive</h2>
<a href="directive-dict.html#Syntax"
rel="Help"><strong>Syntax:</strong></a> CacheMaxExpire
<em>hours</em><br />
<a href="directive-dict.html#Default"
rel="Help"><strong>Default:</strong></a> <code>CacheMaxExpire
24</code><br />
<a href="directive-dict.html#Context"
rel="Help"><strong>Context:</strong></a> server config, virtual
host<br />
<a href="directive-dict.html#Override"
rel="Help"><strong>Override:</strong></a> <em>Not
applicable</em><br />
<a href="directive-dict.html#Status"
rel="Help"><strong>Status:</strong></a> Base<br />
<a href="directive-dict.html#Module"
rel="Help"><strong>Module:</strong></a> mod_proxy<br />
<a href="directive-dict.html#Compatibility"
rel="Help"><strong>Compatibility:</strong></a> CacheMaxExpire
is only available in Apache 1.1 and later.
<p>Specifies the maximum number of <em>hours</em> for which
cachable HTTP documents will be retained without checking the
origin server. Thus, documents will be out of date at most this
number of <em>hours</em> This restriction is enforced even if
an expiry date was supplied with the document.</p>
<hr />
<h2><a id="cachelastmodifiedfactor"
name="cachelastmodifiedfactor">CacheLastModifiedFactor</a>
directive</h2>
<a href="directive-dict.html#Syntax"
rel="Help"><strong>Syntax:</strong></a> CacheLastModifiedFactor
<em>factor</em><br />
<a href="directive-dict.html#Default"
rel="Help"><strong>Default:</strong></a>
<code>CacheLastModifiedFactor 0.1</code><br />
<a href="directive-dict.html#Context"
rel="Help"><strong>Context:</strong></a> server config, virtual
host<br />
<a href="directive-dict.html#Override"
rel="Help"><strong>Override:</strong></a> <em>Not
applicable</em><br />
<a href="directive-dict.html#Status"
rel="Help"><strong>Status:</strong></a> Base<br />
<a href="directive-dict.html#Module"
rel="Help"><strong>Module:</strong></a> mod_proxy<br />
<a href="directive-dict.html#Compatibility"
rel="Help"><strong>Compatibility:</strong></a>
CacheLastModifiedFactor is only available in Apache 1.1 and
later.
<p>If the origin HTTP server did not supply an expiry date for
the document, then estimate one using the formula</p>
<pre>
expiry-period = time-since-last-modification * <em>factor</em>
</pre>
For example, if the document was last modified 10 hours ago,
and <em>factor</em> is 0.1, then the expiry period will be set
to 10*0.1 = 1 hour.
<p>If the expiry-period would be longer than that set by
CacheMaxExpire, then the latter takes precedence.</p>
<hr />
<h2><a id="cachedirlevels"
name="cachedirlevels">CacheDirLevels</a> directive</h2>
<a href="directive-dict.html#Syntax"
rel="Help"><strong>Syntax:</strong></a> CacheDirLevels
<em>levels</em><br />
<a href="directive-dict.html#Default"
rel="Help"><strong>Default:</strong></a> <code>CacheDirLevels
3</code><br />
<a href="directive-dict.html#Context"
rel="Help"><strong>Context:</strong></a> server config, virtual
host<br />
<a href="directive-dict.html#Override"
rel="Help"><strong>Override:</strong></a> <em>Not
applicable</em><br />
<a href="directive-dict.html#Status"
rel="Help"><strong>Status:</strong></a> Base<br />
<a href="directive-dict.html#Module"
rel="Help"><strong>Module:</strong></a> mod_proxy<br />
<a href="directive-dict.html#Compatibility"
rel="Help"><strong>Compatibility:</strong></a> CacheDirLevels
is only available in Apache 1.1 and later.
<p>CacheDirLevels sets the number of <em>levels</em> of
subdirectories in the cache. Cached data will be saved this
many directory levels below CacheRoot.</p>
<hr />
<h2><a id="cachedirlength"
name="cachedirlength">CacheDirLength</a> directive</h2>
<a href="directive-dict.html#Syntax"
rel="Help"><strong>Syntax:</strong></a> CacheDirLength
<em>length</em><br />
<a href="directive-dict.html#Default"
rel="Help"><strong>Default:</strong></a> <code>CacheDirLength
1</code><br />
<a href="directive-dict.html#Context"
rel="Help"><strong>Context:</strong></a> server config, virtual
host<br />
<a href="directive-dict.html#Override"
rel="Help"><strong>Override:</strong></a> <em>Not
applicable</em><br />
<a href="directive-dict.html#Status"
rel="Help"><strong>Status:</strong></a> Base<br />
<a href="directive-dict.html#Module"
rel="Help"><strong>Module:</strong></a> mod_proxy<br />
<a href="directive-dict.html#Compatibility"
rel="Help"><strong>Compatibility:</strong></a> CacheDirLength
is only available in Apache 1.1 and later.
<p>CacheDirLength sets the number of characters in proxy cache
subdirectory names.</p>
<hr />
<h2><a id="cachedefaultexpire"
name="cachedefaultexpire">CacheDefaultExpire</a> directive</h2>
<a href="directive-dict.html#Syntax"
rel="Help"><strong>Syntax:</strong></a> CacheDefaultExpire
<em>hours</em><br />
<a href="directive-dict.html#Default"
rel="Help"><strong>Default:</strong></a>
<code>CacheDefaultExpire 1</code><br />
<a href="directive-dict.html#Context"
rel="Help"><strong>Context:</strong></a> server config, virtual
host<br />
<a href="directive-dict.html#Override"
rel="Help"><strong>Override:</strong></a> <em>Not
applicable</em><br />
<a href="directive-dict.html#Status"
rel="Help"><strong>Status:</strong></a> Base<br />
<a href="directive-dict.html#Module"
rel="Help"><strong>Module:</strong></a> mod_proxy<br />
<a href="directive-dict.html#Compatibility"
rel="Help"><strong>Compatibility:</strong></a>
CacheDefaultExpire is only available in Apache 1.1 and later.
<p>If the document is fetched via a protocol that does not
support expiry times, then use the specified number of
<em>hours</em> as the expiry time. <a
href="#cachemaxexpire">CacheMaxExpire</a> does
<strong>not</strong> override this setting.</p>
<hr />
<h2><a id="nocache" name="nocache">NoCache</a> directive</h2>
<a href="directive-dict.html#Syntax"
rel="Help"><strong>Syntax:</strong></a> NoCache
*|<em>word|host|domain</em> [<em>word|host|domain</em>]
...<br />
<a href="directive-dict.html#Default"
rel="Help"><strong>Default:</strong></a> <em>None</em><br />
<a href="directive-dict.html#Context"
rel="Help"><strong>Context:</strong></a> server config, virtual
host<br />
<a href="directive-dict.html#Override"
rel="Help"><strong>Override:</strong></a> <em>Not
applicable</em><br />
<a href="directive-dict.html#Status"
rel="Help"><strong>Status:</strong></a> Base<br />
<a href="directive-dict.html#Module"
rel="Help"><strong>Module:</strong></a> mod_proxy<br />
<a href="directive-dict.html#Compatibility"
rel="Help"><strong>Compatibility:</strong></a> NoCache is only
available in Apache 1.1 and later.
<p>The NoCache directive specifies a list of words, hosts
and/or domains, separated by spaces. HTTP and non-passworded
FTP documents from matched words, hosts or domains are
<em>not</em> cached 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:</p>
<pre>
NoCache joes-garage.com some-host.co.uk bullwinkle.wotsamattau.edu
</pre>
'bullwinkle.wotsamattau.edu' would also be matched if
referenced by IP address.
<p>Note that 'wotsamattau' would also be sufficient to match
'wotsamattau.edu'.</p>
<p>Note also that</p>
<pre>
NoCache *
</pre>
disables caching completely.
<p> <hr />
<h3 align="CENTER">Apache HTTP Server Version 1.3</h3>
<a href="./"><img src="../images/index.gif" alt="Index" /></a>
<a href="../"><img src="../images/home.gif" alt="Home" /></a>
</p>
</body>
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