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16 <p class="apache">Apache HTTP Server Version 2.1</p>
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21 <div id="page-content">
22 <div id="preamble"><h1>Apache Module mod_proxy</h1>
24 <p><span>Available Languages: </span><a href="../en/mod/mod_proxy.html" title="English"> en </a> |
25 <a href="../ja/mod/mod_proxy.html" hreflang="ja" rel="alternate" title="Japanese"> ja </a></p>
27 <table class="module"><tr><th><a href="module-dict.html#Description">Description:</a></th><td>HTTP/1.1 proxy/gateway server</td></tr>
28 <tr><th><a href="module-dict.html#Status">Status:</a></th><td>Extension</td></tr>
29 <tr><th><a href="module-dict.html#ModuleIdentifier">Module Identifier:</a></th><td>proxy_module</td></tr>
30 <tr><th><a href="module-dict.html#SourceFile">Source File:</a></th><td>mod_proxy.c</td></tr></table>
33 <div class="warning"><h3>Warning</h3>
34 <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
35 network and to the Internet at large.</p>
38 <p>This module implements a proxy/gateway for Apache. It implements
39 proxying capability for <code>AJP13</code> (Apache JServe Protocol
40 version 1.3), <code>FTP</code>, <code>CONNECT</code> (for SSL),
41 <code>HTTP/0.9</code>, <code>HTTP/1.0</code>, and <code>HTTP/1.1</code>.
42 The module can be configured to connect to other proxy modules for these
43 and other protocols.</p>
45 <p>Apache's proxy features are divided into several modules in
46 addition to <code class="module"><a href="../mod/mod_proxy.html">mod_proxy</a></code>:
47 <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>,
48 <code class="module"><a href="../mod/mod_proxy_ajp.html">mod_proxy_ajp</a></code>, <code class="module"><a href="../mod/mod_proxy_balancer.html">mod_proxy_balancer</a></code>,
49 and <code class="module"><a href="../mod/mod_proxy_connect.html">mod_proxy_connect</a></code>. Thus, if you want to use
50 one or more of the particular proxy functions, load
51 <code class="module"><a href="../mod/mod_proxy.html">mod_proxy</a></code> <em>and</em> the appropriate module(s)
52 into the server (either statically at compile-time or dynamically
53 via the <code class="directive"><a href="../mod/mod_so.html#loadmodule">LoadModule</a></code>
56 <p>In addition, extended features are provided by other modules.
57 Caching is provided by <code class="module"><a href="../mod/mod_cache.html">mod_cache</a></code> and related
58 modules. The ability to contact remote servers using the SSL/TLS
59 protocol is provided by the <code>SSLProxy*</code> directives of
60 <code class="module"><a href="../mod/mod_ssl.html">mod_ssl</a></code>. These additional modules will need
61 to be loaded and configured to take advantage of these features.</p>
63 <div id="quickview"><h3 class="directives">Directives</h3>
65 <li><img alt="" src="../images/down.gif" /> <a href="#allowconnect">AllowCONNECT</a></li>
66 <li><img alt="" src="../images/down.gif" /> <a href="#noproxy">NoProxy</a></li>
67 <li><img alt="" src="../images/down.gif" /> <a href="#proxy"><Proxy></a></li>
68 <li><img alt="" src="../images/down.gif" /> <a href="#proxybadheader">ProxyBadHeader</a></li>
69 <li><img alt="" src="../images/down.gif" /> <a href="#proxyblock">ProxyBlock</a></li>
70 <li><img alt="" src="../images/down.gif" /> <a href="#proxydomain">ProxyDomain</a></li>
71 <li><img alt="" src="../images/down.gif" /> <a href="#proxyerroroverride">ProxyErrorOverride</a></li>
72 <li><img alt="" src="../images/down.gif" /> <a href="#proxyiobuffersize">ProxyIOBufferSize</a></li>
73 <li><img alt="" src="../images/down.gif" /> <a href="#proxymatch"><ProxyMatch></a></li>
74 <li><img alt="" src="../images/down.gif" /> <a href="#proxymaxforwards">ProxyMaxForwards</a></li>
75 <li><img alt="" src="../images/down.gif" /> <a href="#proxypass">ProxyPass</a></li>
76 <li><img alt="" src="../images/down.gif" /> <a href="#proxypassreverse">ProxyPassReverse</a></li>
77 <li><img alt="" src="../images/down.gif" /> <a href="#proxypassreversecookiedomain">ProxyPassReverseCookieDomain</a></li>
78 <li><img alt="" src="../images/down.gif" /> <a href="#proxypassreversecookiepath">ProxyPassReverseCookiePath</a></li>
79 <li><img alt="" src="../images/down.gif" /> <a href="#proxypreservehost">ProxyPreserveHost</a></li>
80 <li><img alt="" src="../images/down.gif" /> <a href="#proxyreceivebuffersize">ProxyReceiveBufferSize</a></li>
81 <li><img alt="" src="../images/down.gif" /> <a href="#proxyremote">ProxyRemote</a></li>
82 <li><img alt="" src="../images/down.gif" /> <a href="#proxyremotematch">ProxyRemoteMatch</a></li>
83 <li><img alt="" src="../images/down.gif" /> <a href="#proxyrequests">ProxyRequests</a></li>
84 <li><img alt="" src="../images/down.gif" /> <a href="#proxytimeout">ProxyTimeout</a></li>
85 <li><img alt="" src="../images/down.gif" /> <a href="#proxyvia">ProxyVia</a></li>
89 <li><img alt="" src="../images/down.gif" /> <a href="#forwardreverse">Forward and Reverse Proxies</a></li>
90 <li><img alt="" src="../images/down.gif" /> <a href="#examples">Basic Examples</a></li>
91 <li><img alt="" src="../images/down.gif" /> <a href="#access">Controlling access to your proxy</a></li>
92 <li><img alt="" src="../images/down.gif" /> <a href="#ftp-proxy">FTP Proxy</a></li>
93 <li><img alt="" src="../images/down.gif" /> <a href="#startup">Slow Startup</a></li>
94 <li><img alt="" src="../images/down.gif" /> <a href="#intranet">Intranet Proxy</a></li>
95 <li><img alt="" src="../images/down.gif" /> <a href="#envsettings">Protocol Adjustments</a></li>
96 </ul><h3>See also</h3>
98 <li><code class="module"><a href="../mod/mod_cache.html">mod_cache</a></code></li>
99 <li><code class="module"><a href="../mod/mod_proxy_http.html">mod_proxy_http</a></code></li>
100 <li><code class="module"><a href="../mod/mod_proxy_ftp.html">mod_proxy_ftp</a></code></li>
101 <li><code class="module"><a href="../mod/mod_proxy_connect.html">mod_proxy_connect</a></code></li>
102 <li><code class="module"><a href="../mod/mod_proxy_balancer.html">mod_proxy_balancer</a></code></li>
103 <li><code class="module"><a href="../mod/mod_ssl.html">mod_ssl</a></code></li>
105 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
106 <div class="section">
107 <h2><a name="forwardreverse" id="forwardreverse">Forward and Reverse Proxies</a></h2>
108 <p>Apache can be configured in both a <dfn>forward</dfn> and
109 <dfn>reverse</dfn> proxy mode.</p>
111 <p>An ordinary <dfn>forward proxy</dfn> is an intermediate
112 server that sits between the client and the <em>origin
113 server</em>. In order to get content from the origin server,
114 the client sends a request to the proxy naming the origin server
115 as the target and the proxy then requests the content from the
116 origin server and returns it to the client. The client must be
117 specially configured to use the forward proxy to access other
120 <p>A typical usage of a forward proxy is to provide Internet
121 access to internal clients that are otherwise restricted by a
122 firewall. The forward proxy can also use caching (as provided
123 by <code class="module"><a href="../mod/mod_cache.html">mod_cache</a></code>) to reduce network usage.</p>
125 <p>The forward proxy is activated using the <code class="directive"><a href="#proxyrequests">ProxyRequests</a></code> directive. Because
126 forward proxys allow clients to access arbitrary sites through
127 your server and to hide their true origin, it is essential that
128 you <a href="#access">secure your server</a> so that only
129 authorized clients can access the proxy before activating a
132 <p>A <dfn>reverse proxy</dfn>, by contrast, appears to the
133 client just like an ordinary web server. No special
134 configuration on the client is necessary. The client makes
135 ordinary requests for content in the name-space of the reverse
136 proxy. The reverse proxy then decides where to send those
137 requests, and returns the content as if it was itself the
140 <p>A typical usage of a reverse proxy is to provide Internet
141 users access to a server that is behind a firewall. Reverse
142 proxies can also be used to balance load among several back-end
143 servers, or to provide caching for a slower back-end server.
144 In addition, reverse proxies can be used simply to bring
145 several servers into the same URL space.</p>
147 <p>A reverse proxy is activated using the <code class="directive"><a href="#proxypass">ProxyPass</a></code> directive or the
148 <code>[P]</code> flag to the <code class="directive"><a href="../mod/mod_rewrite.html#rewriterule">RewriteRule</a></code> directive. It is
149 <strong>not</strong> necessary to turn <code class="directive"><a href="#proxyrequests">ProxyRequests</a></code> on in order to
150 configure a reverse proxy.</p>
151 </div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
152 <div class="section">
153 <h2><a name="examples" id="examples">Basic Examples</a></h2>
155 <p>The examples below are only a very basic idea to help you
156 get started. Please read the documentation on the individual
159 <p>In addition, if you wish to have caching enabled, consult
160 the documentation from <code class="module"><a href="../mod/mod_cache.html">mod_cache</a></code>.</p>
162 <div class="example"><h3>Forward Proxy</h3><p><code>
163 ProxyRequests On<br />
166 <Proxy *><br />
167 <span class="indent">
168 Order deny,allow<br />
170 Allow from internal.example.com<br />
175 <div class="example"><h3>Reverse Proxy</h3><p><code>
176 ProxyRequests Off<br />
178 <Proxy *><br />
179 <span class="indent">
180 Order deny,allow<br />
185 ProxyPass /foo http://foo.example.com/bar<br />
186 ProxyPassReverse /foo http://foo.example.com/bar
188 </div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
189 <div class="section">
190 <h2><a name="access" id="access">Controlling access to your proxy</a></h2>
191 <p>You can control who can access your proxy via the <code class="directive"><a href="#proxy"><Proxy></a></code> control block as in
192 the following example:</p>
194 <div class="example"><p><code>
195 <Proxy *><br />
196 <span class="indent">
197 Order Deny,Allow<br />
199 Allow from 192.168.0<br />
204 <p>For more information on access control directives, see
205 <code class="module"><a href="../mod/mod_authz_host.html">mod_authz_host</a></code>.</p>
207 <p>Strictly limiting access is essential if you are using a
208 forward proxy (using the <code class="directive"><a href="#proxyrequests">ProxyRequests</a></code> directive).
209 Otherwise, your server can be used by any client to access
210 arbitrary hosts while hiding his or her true identity. This is
211 dangerous both for your network and for the Internet at large.
212 When using a reverse proxy (using the <code class="directive"><a href="#proxypass">ProxyPass</a></code> directive with
213 <code>ProxyRequests Off</code>), access control is less
214 critical because clients can only contact the hosts that you
215 have specifically configured.</p>
217 </div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
218 <div class="section">
219 <h2><a name="ftp-proxy" id="ftp-proxy">FTP Proxy</a></h2>
222 <h3><a name="mimetypes" id="mimetypes">Why doesn't file type <var>xxx</var>
223 download via FTP?</a></h3>
224 <p>You probably don't have that particular file type defined as
225 <code>application/octet-stream</code> in your proxy's mime.types
226 configuration file. A useful line can be</p>
228 <div class="example"><pre>application/octet-stream bin dms lha lzh exe class tgz taz</pre></div>
229 <p>Alternatively you may prefer to default everything to binary:</p>
230 <div class="example"><pre>DefaultType application/octet-stream</pre></div>
233 <h3><a name="type" id="type">How can I force an FTP ASCII download of
234 File <var>xxx</var>?</a></h3>
235 <p>In the rare situation where you must download a specific file using the
236 FTP <code>ASCII</code> transfer method (while the default transfer is in
237 <code>binary</code> mode), you can override <code class="module"><a href="../mod/mod_proxy.html">mod_proxy</a></code>'s
238 default by suffixing the request with <code>;type=a</code> to force an
239 ASCII transfer. (FTP Directory listings are always executed in ASCII mode,
243 <h3><a name="ftpnonget" id="ftpnonget">How can I do FTP upload?</a></h3>
244 <p>Currently, only GET is supported for FTP in mod_proxy. You can
245 of course use HTTP upload (POST or PUT) through an Apache proxy.</p>
248 <h3><a name="percent2fhck" id="percent2fhck">How can I access FTP files outside
249 of my home directory?</a></h3>
250 <p>An FTP URI is interpreted relative to the home directory of the user
251 who is logging in. Alas, to reach higher directory levels you cannot
252 use /../, as the dots are interpreted by the browser and not actually
253 sent to the FTP server. To address this problem, the so called <dfn>Squid
254 %2f hack</dfn> was implemented in the Apache FTP proxy; it is a
255 solution which is also used by other popular proxy servers like the <a href="http://www.squid-cache.org/">Squid Proxy Cache</a>. By
256 prepending <code>/%2f</code> to the path of your request, you can make
257 such a proxy change the FTP starting directory to <code>/</code> (instead
258 of the home directory). For example, to retrieve the file
259 <code>/etc/motd</code>, you would use the URL:</p>
261 <div class="example"><p><code>
262 ftp://<var>user</var>@<var>host</var>/%2f/etc/motd
266 <h3><a name="ftppass" id="ftppass">How can I hide the FTP cleartext password
267 in my browser's URL line?</a></h3>
268 <p>To log in to an FTP server by username and password, Apache uses
269 different strategies. In absense of a user name and password in the URL
270 altogether, Apache sends an anonymous login to the FTP server,
273 <div class="example"><p><code>
274 user: anonymous<br />
275 password: apache_proxy@
278 <p>This works for all popular FTP servers which are configured for
279 anonymous access.</p>
281 <p>For a personal login with a specific username, you can embed the user
282 name into the URL, like in:</p>
284 <div class="example"><p><code>
285 ftp://<var>username</var>@<var>host</var>/myfile
288 <p>If the FTP server asks for a password when given this username (which
289 it should), then Apache will reply with a <code>401</code> (Authorization
290 required) response, which causes the Browser to pop up the
291 username/password dialog. Upon entering the password, the connection
292 attempt is retried, and if successful, the requested resource is
293 presented. The advantage of this procedure is that your browser does not
294 display the password in cleartext (which it would if you had used</p>
296 <div class="example"><p><code>
297 ftp://<var>username</var>:<var>password</var>@<var>host</var>/myfile
300 <p>in the first place).</p>
302 <div class="note"><h3>Note</h3>
303 <p>The password which is transmitted in such a way is not encrypted on
304 its way. It travels between your browser and the Apache proxy server in
305 a base64-encoded cleartext string, and between the Apache proxy and the
306 FTP server as plaintext. You should therefore think twice before
307 accessing your FTP server via HTTP (or before accessing your personal
308 files via FTP at all!) When using unsecure channels, an eavesdropper
309 might intercept your password on its way.</p>
312 </div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
313 <div class="section">
314 <h2><a name="startup" id="startup">Slow Startup</a></h2>
315 <p>If you're using the <code class="directive"><a href="#proxyblock">ProxyBlock</a></code> directive, hostnames' IP addresses are looked up
316 and cached during startup for later match test. This may take a few
317 seconds (or more) depending on the speed with which the hostname lookups
319 </div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
320 <div class="section">
321 <h2><a name="intranet" id="intranet">Intranet Proxy</a></h2>
322 <p>An Apache proxy server situated in an intranet needs to forward
323 external requests through the company's firewall (for this, configure
324 the <code class="directive"><a href="#proxyremote">ProxyRemote</a></code> directive
325 to forward the respective <var>scheme</var> to the firewall proxy).
326 However, when it has to
327 access resources within the intranet, it can bypass the firewall when
328 accessing hosts. The <code class="directive"><a href="#noproxy">NoProxy</a></code>
329 directive is useful for specifying which hosts belong to the intranet and
330 should be accessed directly.</p>
332 <p>Users within an intranet tend to omit the local domain name from their
333 WWW requests, thus requesting "http://somehost/" instead of
334 <code>http://somehost.example.com/</code>. Some commercial proxy servers
335 let them get away with this and simply serve the request, implying a
336 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
337 a redirect response and send the client to the correct, fully qualified,
338 server address. This is the preferred method since the user's bookmark
339 files will then contain fully qualified hosts.</p>
340 </div><div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
341 <div class="section">
342 <h2><a name="envsettings" id="envsettings">Protocol Adjustments</a></h2>
343 <p>For circumstances where you have a application server which doesn't
344 implement keepalives or HTTP/1.1 properly, there are 2 environment
345 variables which when set send a HTTP/1.0 with no keepalive. These are set
346 via the <code class="directive"><a href="../mod/mod_env.html#setenv">SetEnv</a></code> directive.</p>
348 <p>These are the <code>force-proxy-request-1.0</code> and
349 <code>proxy-nokeepalive</code> notes.</p>
351 <div class="example"><p><code>
352 <Location /buggyappserver/><br />
353 <span class="indent">
354 ProxyPass http://buggyappserver:7001/foo/<br />
355 SetEnv force-proxy-request-1.0 1<br />
356 SetEnv proxy-nokeepalive 1<br />
361 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
362 <div class="directive-section"><h2><a name="AllowCONNECT" id="AllowCONNECT">AllowCONNECT</a> <a name="allowconnect" id="allowconnect">Directive</a></h2>
363 <table class="directive">
364 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Ports that are allowed to <code>CONNECT</code> through the
366 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>AllowCONNECT <var>port</var> [<var>port</var>] ...</code></td></tr>
367 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>AllowCONNECT 443 563</code></td></tr>
368 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
369 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
370 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
372 <p>The <code class="directive">AllowCONNECT</code> directive specifies a list
373 of port numbers to which the proxy <code>CONNECT</code> method may
374 connect. Today's browsers use this method when a <code>https</code>
375 connection is requested and proxy tunneling over HTTP is in effect.</p>
377 <p>By default, only the default https port (<code>443</code>) and the
378 default snews port (<code>563</code>) are enabled. Use the
379 <code class="directive">AllowCONNECT</code> directive to override this default and
380 allow connections to the listed ports only.</p>
382 <p>Note that you'll need to have <code class="module"><a href="../mod/mod_proxy_connect.html">mod_proxy_connect</a></code> present
383 in the server in order to get the support for the <code>CONNECT</code> at
387 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
388 <div class="directive-section"><h2><a name="NoProxy" id="NoProxy">NoProxy</a> <a name="noproxy" id="noproxy">Directive</a></h2>
389 <table class="directive">
390 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Hosts, domains, or networks that will be connected to
392 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>NoProxy <var>host</var> [<var>host</var>] ...</code></td></tr>
393 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
394 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
395 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
397 <p>This directive is only useful for Apache proxy servers within
398 intranets. The <code class="directive">NoProxy</code> directive specifies a
399 list of subnets, IP addresses, hosts and/or domains, separated by
400 spaces. A request to a host which matches one or more of these is
401 always served directly, without forwarding to the configured
402 <code class="directive"><a href="#proxyremote">ProxyRemote</a></code> proxy server(s).</p>
404 <div class="example"><h3>Example</h3><p><code>
405 ProxyRemote * http://firewall.mycompany.com:81<br />
406 NoProxy .mycompany.com 192.168.112.0/21
409 <p>The <var>host</var> arguments to the <code class="directive">NoProxy</code>
410 directive are one of the following type list:</p>
414 <dt><var><a name="domain" id="domain">Domain</a></var></dt>
416 <p>A <dfn>Domain</dfn> is a partially qualified DNS domain name, preceded
417 by a period. It represents a list of hosts which logically belong to the
418 same DNS domain or zone (<em>i.e.</em>, the suffixes of the hostnames are
419 all ending in <var>Domain</var>).</p>
421 <div class="example"><h3>Examples</h3><p><code>
425 <p>To distinguish <var>Domain</var>s from <var><a href="#hostname">Hostname</a></var>s (both syntactically and semantically; a DNS domain can
426 have a DNS A record, too!), <var>Domain</var>s are always written with a
429 <div class="note"><h3>Note</h3>
430 <p>Domain name comparisons are done without regard to the case, and
431 <var>Domain</var>s are always assumed to be anchored in the root of the
432 DNS tree, therefore two domains <code>.MyDomain.com</code> and
433 <code>.mydomain.com.</code> (note the trailing period) are considered
434 equal. Since a domain comparison does not involve a DNS lookup, it is much
435 more efficient than subnet comparison.</p>
439 <dt><var><a name="subnet" id="subnet">SubNet</a></var></dt>
441 <p>A <dfn>SubNet</dfn> is a partially qualified internet address in
442 numeric (dotted quad) form, optionally followed by a slash and the netmask,
443 specified as the number of significant bits in the <var>SubNet</var>. It is
444 used to represent a subnet of hosts which can be reached over a common
445 network interface. In the absence of the explicit net mask it is assumed
446 that omitted (or zero valued) trailing digits specify the mask. (In this
447 case, the netmask can only be multiples of 8 bits wide.) Examples:</p>
450 <dt><code>192.168</code> or <code>192.168.0.0</code></dt>
451 <dd>the subnet 192.168.0.0 with an implied netmask of 16 valid bits
452 (sometimes used in the netmask form <code>255.255.0.0</code>)</dd>
453 <dt><code>192.168.112.0/21</code></dt>
454 <dd>the subnet <code>192.168.112.0/21</code> with a netmask of 21
455 valid bits (also used in the form <code>255.255.248.0</code>)</dd>
458 <p>As a degenerate case, a <em>SubNet</em> with 32 valid bits is the
459 equivalent to an <var><a href="#ipadr">IPAddr</a></var>, while a <var>SubNet</var> with zero
460 valid bits (<em>e.g.</em>, 0.0.0.0/0) is the same as the constant
461 <var>_Default_</var>, matching any IP address.</p></dd>
464 <dt><var><a name="ipaddr" id="ipaddr">IPAddr</a></var></dt>
466 <p>A <dfn>IPAddr</dfn> represents a fully qualified internet address in
467 numeric (dotted quad) form. Usually, this address represents a host, but
468 there need not necessarily be a DNS domain name connected with the
470 <div class="example"><h3>Example</h3><p><code>
474 <div class="note"><h3>Note</h3>
475 <p>An <var>IPAddr</var> does not need to be resolved by the DNS system, so
476 it can result in more effective apache performance.</p>
480 <dt><var><a name="hostname" id="hostname">Hostname</a></var></dt>
482 <p>A <dfn>Hostname</dfn> is a fully qualified DNS domain name which can
483 be resolved to one or more <var><a href="#ipaddr">IPAddrs</a></var> via the
484 DNS domain name service. It represents a logical host (in contrast to
485 <var><a href="#domain">Domain</a></var>s, see above) and must be resolvable
486 to at least one <var><a href="#ipaddr">IPAddr</a></var> (or often to a list
487 of hosts with different <var><a href="#ipaddr">IPAddr</a></var>s).</p>
489 <div class="example"><h3>Examples</h3><p><code>
490 prep.ai.mit.edu<br />
494 <div class="note"><h3>Note</h3>
495 <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
496 DNS lookup can be avoided. Name resolution in Apache can take a remarkable
497 deal of time when the connection to the name server uses a slow PPP
499 <p><var>Hostname</var> comparisons are done without regard to the case,
500 and <var>Hostname</var>s are always assumed to be anchored in the root
501 of the DNS tree, therefore two hosts <code>WWW.MyDomain.com</code>
502 and <code>www.mydomain.com.</code> (note the trailing period) are
503 considered equal.</p>
509 <li><a href="../dns-caveats.html">DNS Issues</a></li>
512 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
513 <div class="directive-section"><h2><a name="Proxy" id="Proxy"><Proxy></a> <a name="proxy" id="proxy">Directive</a></h2>
514 <table class="directive">
515 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Container for directives applied to proxied resources</td></tr>
516 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><Proxy <var>wildcard-url</var>> ...</Proxy></code></td></tr>
517 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
518 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
519 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
521 <p>Directives placed in <code class="directive"><Proxy></code>
522 sections apply only to matching proxied content. Shell-style wildcards are
525 <p>For example, the following will allow only hosts in
526 <code>yournetwork.example.com</code> to access content via your proxy
529 <div class="example"><p><code>
530 <Proxy *><br />
531 <span class="indent">
532 Order Deny,Allow<br />
534 Allow from yournetwork.example.com<br />
539 <p>The following example will process all files in the <code>foo</code>
540 directory of <code>example.com</code> through the <code>INCLUDES</code>
541 filter when they are sent through the proxy server:</p>
543 <div class="example"><p><code>
544 <Proxy http://example.com/foo/*><br />
545 <span class="indent">
546 SetOutputFilter INCLUDES<br />
551 <p>New in Apache 2.1, is the ability to set the various connection
552 parameters to a backend server. The connection parameters are in
553 the form <code>key=value</code>.
556 <tr><th>Parameter</th>
558 <th>Description</th></tr>
561 <td>Minumum number of connections that will always
562 be open to the backend server.</td></tr>
565 <td>Hard Maximum number of connections that will be
566 allowed to the backend server. The default for a Hard Maximum
567 for the number of connections is the number of threads per process in the
568 active MPM. In the Prefork MPM, this is always 1, while with the Worker MPM
569 it is controlled by the <code class="directive">ThreadsPerChild</code>.
570 Apache will never create more than the Hard Maximum connections
571 to the backend server.</td></tr>
574 <td>Upto the Soft Maximum
575 number of connections will be created on demand. Any connections above
576 <code>smax</code> are subject to a time to live or <code>ttl</code>.
580 <td>Time To Live for the inactive connections above the
581 <code>smax</code> connections in seconds. Apache will close all
582 connections that has not been used inside that time period.
585 <td><code class="directive">Timeout</code></td>
586 <td>Connection timeout in seconds.
587 If not set the Apache will wait until the free connection
588 is available. This directive is used for limiting the number
589 of connections to the backend server together with <code>max</code>
594 <td>If set this will be the maximum time to wait for a free
595 connection in the connection pool. If there are no free connections
596 in the pool the Apache will return <code>SERVER_BUSY</code> status to
599 <tr><td>keepalive</td>
601 <td>This parameter should be used when you have a firewall between your
602 Apache and the backend server, who tend to drop inactive connections.
603 This flag will tell the Operating System to send <code>KEEP_ALIVE</code>
604 messages on inactive connections (interval depends on global OS settings,
605 generally 120ms), and thus prevent the firewall to drop the connection.
606 To enable keepalive set this property value to <code>On</code>.
610 <td>Connection pool worker retry timeout in seconds.
611 If the connection pool worker to the backend server is in the error state,
612 Apache will not forward any requests to that server until the timeout
613 expires. This enables to shut down the backend server for maintenance,
614 and bring it back online later.
616 <tr><td>loadfactor</td>
618 <td>Worker load factor. Used with BalancerMember.
619 It is a number between 1 and 100 and defines the normalized weighted
620 load applied to the worker.
624 <td>Route of the worker when used inside load balancer.
625 The route is a value appended to seesion id.
627 <tr><td>redirect</td>
629 <td>Redirection Route of the worker. This value is usually
630 set dynamically to enable safe removal of the node from
631 the cluster. If set all requests without session id will be
632 redirected to the BalancerMember that has route parametar
638 <p>If the Proxy directive scheme starts with the
639 <code>balancer://</code> then a virtual worker that does not really
640 communicate with the backend server will be created. Instead it is responsible
641 for the management of several "real" workers. In that case the special set of
642 parameters can be add to this virtual worker.
645 <tr><th>Parameter</th>
647 <th>Description</th></tr>
648 <tr><td>lbmethod</td>
650 <td>Balancer load-balance method. Select the load-balancing scheduler
651 method to use. Either <code>requests</code>, to perform weighted
652 request counting or <code>traffic</code>, to perform weighted
653 traffic byte count balancing. Default is <code>requests</code>.
655 <tr><td>stickysession</td>
657 <td>Balancer sticky session name. The value is usually set to something
658 like <code>JSESSIONID</code> or <code>PHPSESSIONID</code>,
659 and it depends on the backend application server that support sessions.
661 <tr><td>nofailover</td>
663 <td>If set to <code>On</code> the session will break if the worker is in
664 error state or disabled. Set this value to On if backend servers do not
665 support session replication.
669 <td>Balancer timeout in seconds. If set this will be the maximum time
670 to wait for a free worker. Default is not to wait.
672 <tr><td>maxattempts</td>
674 <td>Maximum number of failover attempts before giving up.
678 <div class="example"><p><code>
679 <Proxy balancer://mycluster stickysession=jsessionid nofailover=On><br />
680 <span class="indent">
681 BalancerMember http://1.2.3.4:8009<br />
682 BalancerMember http://1.2.3.5:8009<br />
683 BalancerMember http://1.2.3.6:8009<br />
690 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
691 <div class="directive-section"><h2><a name="ProxyBadHeader" id="ProxyBadHeader">ProxyBadHeader</a> <a name="proxybadheader" id="proxybadheader">Directive</a></h2>
692 <table class="directive">
693 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Determines how to handle bad header lines in a
695 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyBadHeader IsError|Ignore|StartBody</code></td></tr>
696 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ProxyBadHeader IsError</code></td></tr>
697 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
698 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
699 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
700 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>available in Apache 2.0.44 and later</td></tr>
702 <p>The <code class="directive">ProxyBadHeader</code> directive determines the
703 behaviour of <code class="module"><a href="../mod/mod_proxy.html">mod_proxy</a></code> if it receives syntactically invalid
704 header lines (<em>i.e.</em> containing no colon). The following arguments
708 <dt><code>IsError</code></dt>
709 <dd>Abort the request and end up with a 502 (Bad Gateway) response. This is
710 the default behaviour.</dd>
712 <dt><code>Ignore</code></dt>
713 <dd>Treat bad header lines as if they weren't sent.</dd>
715 <dt><code>StartBody</code></dt>
716 <dd>When receiving the first bad header line, finish reading the headers and
717 treat the remainder as body. This helps to work around buggy backend servers
718 which forget to insert an empty line between the headers and the body.</dd>
722 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
723 <div class="directive-section"><h2><a name="ProxyBlock" id="ProxyBlock">ProxyBlock</a> <a name="proxyblock" id="proxyblock">Directive</a></h2>
724 <table class="directive">
725 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Words, hosts, or domains that are banned from being
727 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyBlock *|<var>word</var>|<var>host</var>|<var>domain</var>
728 [<var>word</var>|<var>host</var>|<var>domain</var>] ...</code></td></tr>
729 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
730 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
731 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
733 <p>The <code class="directive">ProxyBlock</code> directive specifies a list of
734 words, hosts and/or domains, separated by spaces. HTTP, HTTPS, and
735 FTP document requests to sites whose names contain matched words,
736 hosts or domains are <em>blocked</em> by the proxy server. The proxy
737 module will also attempt to determine IP addresses of list items which
738 may be hostnames during startup, and cache them for match test as
739 well. That may slow down the startup time of the server.</p>
741 <div class="example"><h3>Example</h3><p><code>
742 ProxyBlock joes-garage.com some-host.co.uk rocky.wotsamattau.edu
745 <p><code>rocky.wotsamattau.edu</code> would also be matched if referenced by
748 <p>Note that <code>wotsamattau</code> would also be sufficient to match
749 <code>wotsamattau.edu</code>.</p>
751 <p>Note also that</p>
753 <div class="example"><p><code>
757 <p>blocks connections to all sites.</p>
760 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
761 <div class="directive-section"><h2><a name="ProxyDomain" id="ProxyDomain">ProxyDomain</a> <a name="proxydomain" id="proxydomain">Directive</a></h2>
762 <table class="directive">
763 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Default domain name for proxied requests</td></tr>
764 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyDomain <var>Domain</var></code></td></tr>
765 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
766 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
767 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
769 <p>This directive is only useful for Apache proxy servers within
770 intranets. The <code class="directive">ProxyDomain</code> directive specifies
771 the default domain which the apache proxy server will belong to. If a
772 request to a host without a domain name is encountered, a redirection
773 response to the same host with the configured <var>Domain</var> appended
774 will be generated.</p>
776 <div class="example"><h3>Example</h3><p><code>
777 ProxyRemote * http://firewall.mycompany.com:81<br />
778 NoProxy .mycompany.com 192.168.112.0/21<br />
779 ProxyDomain .mycompany.com
783 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
784 <div class="directive-section"><h2><a name="ProxyErrorOverride" id="ProxyErrorOverride">ProxyErrorOverride</a> <a name="proxyerroroverride" id="proxyerroroverride">Directive</a></h2>
785 <table class="directive">
786 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Override error pages for proxied content</td></tr>
787 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyErrorOverride On|Off</code></td></tr>
788 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ProxyErrorOverride Off</code></td></tr>
789 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
790 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
791 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
792 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in version 2.0 and later</td></tr>
794 <p>This directive is useful for reverse-proxy setups, where you want to
795 have a common look and feel on the error pages seen by the end user.
796 This also allows for included files (via
797 <code class="module"><a href="../mod/mod_include.html">mod_include</a></code>'s SSI) to get
798 the error code and act accordingly (default behavior would display
799 the error page of the proxied server, turning this on shows the SSI
803 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
804 <div class="directive-section"><h2><a name="ProxyIOBufferSize" id="ProxyIOBufferSize">ProxyIOBufferSize</a> <a name="proxyiobuffersize" id="proxyiobuffersize">Directive</a></h2>
805 <table class="directive">
806 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Determine size of internal data throughput buffer</td></tr>
807 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyIOBufferSize <var>bytes</var></code></td></tr>
808 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ProxyIOBufferSize 8192</code></td></tr>
809 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
810 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
811 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
813 <p>The <code class="directive">ProxyIOBufferSize</code> directive adjusts the size
814 of the internal buffer, which is used as a scratchpad for the data between
815 input and output. The size must be less or equal <code>8192</code>.</p>
817 <p>In almost every case there's no reason to change that value.</p>
820 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
821 <div class="directive-section"><h2><a name="ProxyMatch" id="ProxyMatch"><ProxyMatch></a> <a name="proxymatch" id="proxymatch">Directive</a></h2>
822 <table class="directive">
823 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Container for directives applied to regular-expression-matched
824 proxied resources</td></tr>
825 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code><ProxyMatch <var>regex</var>> ...</ProxyMatch></code></td></tr>
826 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
827 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
828 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
830 <p>The <code class="directive"><ProxyMatch></code> directive is
831 identical to the <code class="directive"><a href="#proxy"><Proxy></a></code> directive, except it matches URLs
832 using regular expressions.</p>
835 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
836 <div class="directive-section"><h2><a name="ProxyMaxForwards" id="ProxyMaxForwards">ProxyMaxForwards</a> <a name="proxymaxforwards" id="proxymaxforwards">Directive</a></h2>
837 <table class="directive">
838 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Maximium number of proxies that a request can be forwarded
840 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyMaxForwards <var>number</var></code></td></tr>
841 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ProxyMaxForwards 10</code></td></tr>
842 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
843 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
844 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
845 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache 2.0 and later</td></tr>
847 <p>The <code class="directive">ProxyMaxForwards</code> directive specifies the
848 maximum number of proxies through which a request may pass, if there's no
849 <code>Max-Forwards</code> header supplied with the request. This is
850 set to prevent infinite proxy loops, or a DoS attack.</p>
852 <div class="example"><h3>Example</h3><p><code>
857 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
858 <div class="directive-section"><h2><a name="ProxyPass" id="ProxyPass">ProxyPass</a> <a name="proxypass" id="proxypass">Directive</a></h2>
859 <table class="directive">
860 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Maps remote servers into the local server URL-space</td></tr>
861 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyPass [<var>path</var>] !|<var>url</var> [<var>key=value</var> <var>key=value</var> ...]]</code></td></tr>
862 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory</td></tr>
863 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
864 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
866 <p>This directive allows remote servers to be mapped into the space of
867 the local server; the local server does not act as a proxy in the
868 conventional sense, but appears to be a mirror of the remote
869 server. <var>path</var> is the name of a local virtual path; <var>url</var>
870 is a partial URL for the remote server and cannot include a query
873 <p>Suppose the local server has address <code>http://example.com/</code>;
876 <div class="example"><p><code>
877 ProxyPass /mirror/foo/ http://backend.example.com/
880 <p>will cause a local request for
881 <code>http://example.com/mirror/foo/bar</code> to be internally converted
882 into a proxy request to <code>http://backend.example.com/bar</code>.</p>
884 <p>The <code>!</code> directive is useful in situations where you don't want
885 to reverse-proxy a subdirectory, <em>e.g.</em></p>
887 <div class="example"><p><code>
888 ProxyPass /mirror/foo/i !<br />
889 ProxyPass /mirror/foo http://backend.example.com
892 <p>will proxy all requests to <code>/mirror/foo</code> to
893 <code>backend.example.com</code> <em>except</em> requests made to
894 <code>/mirror/foo/i</code>.</p>
896 <div class="note"><h3>Note</h3>
897 <p>Order is important. you need to put the exclusions <em>before</em> the
898 general <code class="directive">ProxyPass</code> directive.</p>
901 <p>New in Apache 2.1, is the ability to use pooled connections to a
902 backend server. Using the <code>key=value</code> parameters it is possible
903 to tune this connection pooling. The default for a <code>Hard Maximum</code>
904 for the number of connections is the number of threads per process in the
905 active MPM. In the Prefork MPM, this is always 1, while with the Worker MPM
906 it is controlled by the <code class="directive">ThreadsPerChild</code>.</p>
908 <p>Setting <code>min</code> will determine how many connections will always
909 be open to the backend server. Upto the Soft Maximum or <code>smax</code>
910 number of connections will be created on demand. Any connections above
911 <code>smax</code> are subject to a time to live or <code>ttl</code>. Apache
912 will never create more than the Hard Maximum or <code>max</code> connections
913 to the backend server.</p>
915 <div class="example"><p><code>
916 ProxyPass /example http://backend.example.com smax=5 max=20 ttl=120 retry=300
919 <p>When used inside a <code class="directive"><a href="../mod/core.html#location"><Location></a></code> section, the first argument is omitted and the local
920 directory is obtained from the <code class="directive"><a href="../mod/core.html#location"><Location></a></code>.</p>
922 <div class="warning">The <code class="directive"><a href="#proxyrequests">ProxyRequests</a></code> directive should
923 usually be set <strong>off</strong> when using
924 <code class="directive">ProxyPass</code>.</div>
926 <p>If you require a more flexible reverse-proxy configuration, see the
927 <code class="directive"><a href="../mod/mod_rewrite.html#rewriterule">RewriteRule</a></code> directive with the
928 <code>[P]</code> flag.</p>
931 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
932 <div class="directive-section"><h2><a name="ProxyPassReverse" id="ProxyPassReverse">ProxyPassReverse</a> <a name="proxypassreverse" id="proxypassreverse">Directive</a></h2>
933 <table class="directive">
934 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Adjusts the URL in HTTP response headers sent from a reverse
935 proxied server</td></tr>
936 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyPassReverse [<var>path</var>] <var>url</var></code></td></tr>
937 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory</td></tr>
938 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
939 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
941 <p>This directive lets Apache adjust the URL in the <code>Location</code>,
942 <code>Content-Location</code> and <code>URI</code> headers on HTTP redirect
943 responses. This is essential when Apache is used as a reverse proxy to avoid
944 by-passing the reverse proxy because of HTTP redirects on the backend
945 servers which stay behind the reverse proxy.</p>
947 <p>Only the HTTP response headers specifically mentioned above
948 will be rewritten. Apache will not rewrite other response
949 headers, nor will it rewrite URL references inside HTML pages.
950 This means that if the proxied content contains absolute URL
951 references, they will by-pass the proxy. A third-party module
952 that will look inside the HTML and rewrite URL references is Nick
953 Kew's <a href="http://apache.webthing.com/software/mod_proxy_html/">mod_proxy_html</a>.</p>
955 <p><var>path</var> is the name of a local virtual path. <var>url</var> is a
956 partial URL for the remote server - the same way they are used for the
957 <code class="directive"><a href="#proxypass">ProxyPass</a></code> directive.</p>
959 <p>For example, suppose the local server has address
960 <code>http://example.com/</code>; then</p>
962 <div class="example"><p><code>
963 ProxyPass /mirror/foo/ http://backend.example.com/<br />
964 ProxyPassReverse /mirror/foo/ http://backend.example.com/<br />
965 ProxyPassReverseCookieDomain backend.example.com public.example.com<br />
966 ProxyPassReverseCookiePath / /mirror/foo/
969 <p>will not only cause a local request for the
970 <code>http://example.com/mirror/foo/bar</code> to be internally converted
971 into a proxy request to <code>http://backend.example.com/bar</code>
972 (the functionality <code>ProxyPass</code> provides here). It also takes care
973 of redirects the server <code>backend.example.com</code> sends: when
974 <code>http://backend.example.com/bar</code> is redirected by him to
975 <code>http://backend.example.com/quux</code> Apache adjusts this to
976 <code>http://example.com/mirror/foo/quux</code> before forwarding the HTTP
977 redirect response to the client. Note that the hostname used for
978 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>
980 <p>Note that this <code class="directive">ProxyPassReverse</code> directive can
981 also be used in conjunction with the proxy pass-through feature
982 (<code>RewriteRule ... [P]</code>) from <code class="module"><a href="../mod/mod_rewrite.html">mod_rewrite</a></code>
983 because its doesn't depend on a corresponding <code class="directive"><a href="#proxypass">ProxyPass</a></code> directive.</p>
985 <p>When used inside a <code class="directive"><a href="../mod/core.html#location"><Location></a></code> section, the first argument is omitted and the local
986 directory is obtained from the <code class="directive"><a href="../mod/core.html#location"><Location></a></code>.</p>
989 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
990 <div class="directive-section"><h2><a name="ProxyPassReverseCookieDomain" id="ProxyPassReverseCookieDomain">ProxyPassReverseCookieDomain</a> <a name="proxypassreversecookiedomain" id="proxypassreversecookiedomain">Directive</a></h2>
991 <table class="directive">
992 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Adjusts the Domain string in Set-Cookie headers from a reverse-
993 proxied server</td></tr>
994 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyPassReverseCookieDomain <var>internal-domain</var> <var>public-domain</var></code></td></tr>
995 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory</td></tr>
996 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
997 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
999 <p>Usage is basically similar to
1000 <code class="directive"><a href="#proxypassreverse">ProxyPassReverse</a></code>, but instead of
1001 rewriting headers that are a URL, this rewrites the <code>domain</code>
1002 string in <code>Set-Cookie</code> headers.</p>
1005 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1006 <div class="directive-section"><h2><a name="ProxyPassReverseCookiePath" id="ProxyPassReverseCookiePath">ProxyPassReverseCookiePath</a> <a name="proxypassreversecookiepath" id="proxypassreversecookiepath">Directive</a></h2>
1007 <table class="directive">
1008 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Adjusts the Path string in Set-Cookie headers from a reverse-
1009 proxied server</td></tr>
1010 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyPassReverseCookiePath <var>internal-path</var> <var>public-path</var></code></td></tr>
1011 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host, directory</td></tr>
1012 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
1013 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
1015 <p>Usage is basically similar to
1016 <code class="directive"><a href="#proxypassreverse">ProxyPassReverse</a></code>, but instead of
1017 rewriting headers that are a URL, this rewrites the <code>path</code>
1018 string in <code>Set-Cookie</code> headers.</p>
1021 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1022 <div class="directive-section"><h2><a name="ProxyPreserveHost" id="ProxyPreserveHost">ProxyPreserveHost</a> <a name="proxypreservehost" id="proxypreservehost">Directive</a></h2>
1023 <table class="directive">
1024 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Use incoming Host HTTP request header for proxy
1026 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyPreserveHost On|Off</code></td></tr>
1027 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ProxyPreserveHost Off</code></td></tr>
1028 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
1029 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
1030 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
1031 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache 2.0.31 and later.</td></tr>
1033 <p>When enabled, this option will pass the Host: line from the incoming
1034 request to the proxied host, instead of the hostname specified in the
1035 <code class="directive">ProxyPass</code> line.</p>
1037 <p>This option should normally be turned <code>Off</code>. It is mostly
1038 useful in special configurations like proxied mass name-based virtual
1039 hosting, where the original Host header needs to be evaluated by the
1043 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1044 <div class="directive-section"><h2><a name="ProxyReceiveBufferSize" id="ProxyReceiveBufferSize">ProxyReceiveBufferSize</a> <a name="proxyreceivebuffersize" id="proxyreceivebuffersize">Directive</a></h2>
1045 <table class="directive">
1046 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Network buffer size for proxied HTTP and FTP
1047 connections</td></tr>
1048 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyReceiveBufferSize <var>bytes</var></code></td></tr>
1049 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ProxyReceiveBufferSize 0</code></td></tr>
1050 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
1051 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
1052 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
1054 <p>The <code class="directive">ProxyReceiveBufferSize</code> directive specifies an
1055 explicit (TCP/IP) network buffer size for proxied HTTP and FTP connections,
1056 for increased throughput. It has to be greater than <code>512</code> or set
1057 to <code>0</code> to indicate that the system's default buffer size should
1060 <div class="example"><h3>Example</h3><p><code>
1061 ProxyReceiveBufferSize 2048
1065 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1066 <div class="directive-section"><h2><a name="ProxyRemote" id="ProxyRemote">ProxyRemote</a> <a name="proxyremote" id="proxyremote">Directive</a></h2>
1067 <table class="directive">
1068 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Remote proxy used to handle certain requests</td></tr>
1069 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyRemote <var>match</var> <var>remote-server</var></code></td></tr>
1070 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
1071 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
1072 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
1074 <p>This defines remote proxies to this proxy. <var>match</var> is either the
1075 name of a URL-scheme that the remote server supports, or a partial URL
1076 for which the remote server should be used, or <code>*</code> to indicate
1077 the server should be contacted for all requests. <var>remote-server</var> is
1078 a partial URL for the remote server. Syntax:</p>
1080 <div class="example"><p><code>
1081 <dfn>remote-server</dfn> =
1082 <var>scheme</var>://<var>hostname</var>[:<var>port</var>]
1085 <p><var>scheme</var> is effectively the protocol that should be used to
1086 communicate with the remote server; only <code>http</code> is supported by
1089 <div class="example"><h3>Example</h3><p><code>
1090 ProxyRemote http://goodguys.com/ http://mirrorguys.com:8000<br />
1091 ProxyRemote * http://cleversite.com<br />
1092 ProxyRemote ftp http://ftpproxy.mydomain.com:8080
1095 <p>In the last example, the proxy will forward FTP requests, encapsulated
1096 as yet another HTTP proxy request, to another proxy which can handle
1099 <p>This option also supports reverse proxy configuration - a backend
1100 webserver can be embedded within a virtualhost URL space even if that
1101 server is hidden by another forward proxy.</p>
1104 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1105 <div class="directive-section"><h2><a name="ProxyRemoteMatch" id="ProxyRemoteMatch">ProxyRemoteMatch</a> <a name="proxyremotematch" id="proxyremotematch">Directive</a></h2>
1106 <table class="directive">
1107 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Remote proxy used to handle requests matched by regular
1108 expressions</td></tr>
1109 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyRemoteMatch <var>regex</var> <var>remote-server</var></code></td></tr>
1110 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
1111 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
1112 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
1114 <p>The <code class="directive">ProxyRemoteMatch</code> is identical to the
1115 <code class="directive"><a href="#proxyremote">ProxyRemote</a></code> directive, except the
1116 first argument is a regular expression match against the requested URL.</p>
1119 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1120 <div class="directive-section"><h2><a name="ProxyRequests" id="ProxyRequests">ProxyRequests</a> <a name="proxyrequests" id="proxyrequests">Directive</a></h2>
1121 <table class="directive">
1122 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Enables forward (standard) proxy requests</td></tr>
1123 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyRequests On|Off</code></td></tr>
1124 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ProxyRequests Off</code></td></tr>
1125 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
1126 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
1127 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
1129 <p>This allows or prevents Apache from functioning as a forward proxy
1130 server. (Setting ProxyRequests to <code>Off</code> does not disable use of
1131 the <code class="directive"><a href="#proxypass">ProxyPass</a></code> directive.)</p>
1133 <p>In a typical reverse proxy configuration, this option should be set to
1134 <code>Off</code>.</p>
1136 <p>In order to get the functionality of proxying HTTP or FTP sites, you
1137 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>
1138 (or both) present in the server.</p>
1140 <div class="warning"><h3>Warning</h3>
1141 <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
1142 both to your network and to the Internet at large.</p>
1146 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1147 <div class="directive-section"><h2><a name="ProxyTimeout" id="ProxyTimeout">ProxyTimeout</a> <a name="proxytimeout" id="proxytimeout">Directive</a></h2>
1148 <table class="directive">
1149 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Network timeout for proxied requests</td></tr>
1150 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyTimeout <var>seconds</var></code></td></tr>
1151 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ProxyTimeout 300</code></td></tr>
1152 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
1153 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
1154 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
1155 <tr><th><a href="directive-dict.html#Compatibility">Compatibility:</a></th><td>Available in Apache 2.0.31 and later</td></tr>
1157 <p>This directive allows a user to specifiy a timeout on proxy requests.
1158 This is useful when you have a slow/buggy appserver which hangs, and you
1159 would rather just return a timeout and fail gracefully instead of waiting
1160 however long it takes the server to return.</p>
1163 <div class="top"><a href="#page-header"><img alt="top" src="../images/up.gif" /></a></div>
1164 <div class="directive-section"><h2><a name="ProxyVia" id="ProxyVia">ProxyVia</a> <a name="proxyvia" id="proxyvia">Directive</a></h2>
1165 <table class="directive">
1166 <tr><th><a href="directive-dict.html#Description">Description:</a></th><td>Information provided in the <code>Via</code> HTTP response
1167 header for proxied requests</td></tr>
1168 <tr><th><a href="directive-dict.html#Syntax">Syntax:</a></th><td><code>ProxyVia On|Off|Full|Block</code></td></tr>
1169 <tr><th><a href="directive-dict.html#Default">Default:</a></th><td><code>ProxyVia Off</code></td></tr>
1170 <tr><th><a href="directive-dict.html#Context">Context:</a></th><td>server config, virtual host</td></tr>
1171 <tr><th><a href="directive-dict.html#Status">Status:</a></th><td>Extension</td></tr>
1172 <tr><th><a href="directive-dict.html#Module">Module:</a></th><td>mod_proxy</td></tr>
1174 <p>This directive controls the use of the <code>Via:</code> HTTP
1175 header by the proxy. Its intended use is to control the flow of
1176 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
1177 14.45 for an explanation of <code>Via:</code> header lines.</p>
1180 <li>If set to <code>Off</code>, which is the default, no special processing
1181 is performed. If a request or reply contains a <code>Via:</code> header,
1182 it is passed through unchanged.</li>
1184 <li>If set to <code>On</code>, each request and reply will get a
1185 <code>Via:</code> header line added for the current host.</li>
1187 <li>If set to <code>Full</code>, each generated <code>Via:</code> header
1188 line will additionally have the Apache server version shown as a
1189 <code>Via:</code> comment field.</li>
1191 <li>If set to <code>Block</code>, every proxy request will have all its
1192 <code>Via:</code> header lines removed. No new <code>Via:</code> header will
1198 <div class="bottomlang">
1199 <p><span>Available Languages: </span><a href="../en/mod/mod_proxy.html" title="English"> en </a> |
1200 <a href="../ja/mod/mod_proxy.html" hreflang="ja" rel="alternate" title="Japanese"> ja </a></p>
1201 </div><div id="footer">
1202 <p class="apache">Copyright 1995-2005 The Apache Software Foundation or its licensors, as applicable.<br />Licensed under the <a href="http://www.apache.org/licenses/LICENSE-2.0">Apache License, Version 2.0</a>.</p>
1203 <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>