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3726777f47ac4bba3e21b075905959bbea47e72eerikabele --><title>Name-based Virtual Host Support - Apache HTTP Server</title><link href="/style/css/manual.css" rel="stylesheet" media="all" type="text/css" title="Main stylesheet" /><link href="/style/css/manual-loose-100pc.css" rel="alternate stylesheet" media="all" type="text/css" title="No Sidebar - Default font size" /><link href="/style/css/manual-print.css" rel="stylesheet" media="print" type="text/css" /><link href="/images/favicon.ico" rel="shortcut icon" /></head><body id="manual-page"><div id="page-header"><p class="menu"><a href="/mod/">Modules</a> | <a href="/mod/directives.html">Directives</a> | <a href="/faq/">FAQ</a> | <a href="/glossary.html">Glossary</a> | <a href="/sitemap.html">Sitemap</a></p><p class="apache">Apache HTTP Server Version 2.0</p><img alt="" src="/images/feather.gif" /></div><div class="up"><a href="./"><img title="&lt;-" alt="&lt;-" src="/images/left.gif" /></a></div><div id="path"><a href="http://www.apache.org/">Apache</a> &gt; <a href="http://httpd.apache.org/">HTTP Server</a> &gt; <a href="http://httpd.apache.org/docs-project/">Documentation</a> &gt; <a href="../">Version 2.0</a></div><div id="page-content"><div id="preamble"><h1>Name-based Virtual Host Support</h1>
3726777f47ac4bba3e21b075905959bbea47e72eerikabele
3726777f47ac4bba3e21b075905959bbea47e72eerikabele <p>This document describes when and how to use name-based virtual hosts.</p>
3726777f47ac4bba3e21b075905959bbea47e72eerikabele
3726777f47ac4bba3e21b075905959bbea47e72eerikabele</div><div id="quickview"><ul id="toc"><li><img alt="" src="/images/down.gif" /> <a href="#namevip">Name-based vs. IP-based Virtual Hosts</a></li><li><img alt="" src="/images/down.gif" /> <a href="#using">Using Name-based Virtual Hosts</a></li><li><img alt="" src="/images/down.gif" /> <a href="#">Compatibility with Older Browsers</a></li></ul><h3>See also</h3><ul class="seealso"><li><a href="ip-based.html">IP-based Virtual Host Support</a></li><li><a href="details.html">An In-Depth Discussion of Virtual Host Matching</a></li><li><a href="mass.html">Dynamically configured mass virtual hosting</a></li><li><a href="examples.html">Virtual Host examples for common setups</a></li><li><a href="examples.html#serverpath">ServerPath configuration example</a></li></ul></div><div class="top"><a href="#page-header"><img alt="top" src="/images/up.gif" /></a></div><div class="section"><h2><a name="namevip" id="namevip">Name-based vs. IP-based Virtual Hosts</a></h2>
3726777f47ac4bba3e21b075905959bbea47e72eerikabele
3726777f47ac4bba3e21b075905959bbea47e72eerikabele <p>IP-based virtual hosts use the IP address of the connection to
3726777f47ac4bba3e21b075905959bbea47e72eerikabele determine the correct virtual host to serve. Therefore you need to
3726777f47ac4bba3e21b075905959bbea47e72eerikabele have a separate IP address for each host. With name-based virtual
3726777f47ac4bba3e21b075905959bbea47e72eerikabele hosting, the server relies on the client to report the hostname as
3726777f47ac4bba3e21b075905959bbea47e72eerikabele part of the HTTP headers. Using this technique, many different hosts
3726777f47ac4bba3e21b075905959bbea47e72eerikabele can share the same IP address.</p>
3726777f47ac4bba3e21b075905959bbea47e72eerikabele
3726777f47ac4bba3e21b075905959bbea47e72eerikabele <p>Name-based virtual hosting is usually simpler, since you need
3726777f47ac4bba3e21b075905959bbea47e72eerikabele only configure your DNS server to map each hostname to the correct
3726777f47ac4bba3e21b075905959bbea47e72eerikabele IP address and then configure the Apache HTTP Server to recognize
3726777f47ac4bba3e21b075905959bbea47e72eerikabele the different hostnames. Name-based virtual hosting also eases
3726777f47ac4bba3e21b075905959bbea47e72eerikabele the demand for scarce IP addresses. Therefore you should use
3726777f47ac4bba3e21b075905959bbea47e72eerikabele name-based virtual hosting unless there is a specific reason to
3726777f47ac4bba3e21b075905959bbea47e72eerikabele choose IP-based virtual hosting. Some reasons why you might consider
3726777f47ac4bba3e21b075905959bbea47e72eerikabele using IP-based virtual hosting:</p>
3726777f47ac4bba3e21b075905959bbea47e72eerikabele
3726777f47ac4bba3e21b075905959bbea47e72eerikabele <ul>
3726777f47ac4bba3e21b075905959bbea47e72eerikabele <li>Some ancient clients are not compatible with name-based virtual
3726777f47ac4bba3e21b075905959bbea47e72eerikabele hosting. For name-based virtual hosting to work, the client must send
3726777f47ac4bba3e21b075905959bbea47e72eerikabele the HTTP Host header. This is required by HTTP/1.1, and is
3726777f47ac4bba3e21b075905959bbea47e72eerikabele implemented by all modern HTTP/1.0 browsers as an extension. If you
3726777f47ac4bba3e21b075905959bbea47e72eerikabele need to support obsolete clients and still use name-based virtual
3726777f47ac4bba3e21b075905959bbea47e72eerikabele hosting, a possible technique is discussed at the end of this
3726777f47ac4bba3e21b075905959bbea47e72eerikabele document.</li>
3726777f47ac4bba3e21b075905959bbea47e72eerikabele
3726777f47ac4bba3e21b075905959bbea47e72eerikabele <li>Name-based virtual hosting cannot be used with SSL secure servers
3726777f47ac4bba3e21b075905959bbea47e72eerikabele because of the nature of the SSL protocol.</li>
3726777f47ac4bba3e21b075905959bbea47e72eerikabele
d03dd7e22aeb4b6940fb43d02db1233c1bedd799nd <li>Some operating systems and network equipment implement bandwidth
d03dd7e22aeb4b6940fb43d02db1233c1bedd799nd management techniques that cannot differentiate between hosts unless
3726777f47ac4bba3e21b075905959bbea47e72eerikabele they are on separate IP addresses.</li>
3726777f47ac4bba3e21b075905959bbea47e72eerikabele </ul>
3726777f47ac4bba3e21b075905959bbea47e72eerikabele
3726777f47ac4bba3e21b075905959bbea47e72eerikabele</div><div class="top"><a href="#page-header"><img alt="top" src="/images/up.gif" /></a></div><div class="section"><h2><a name="using" id="using">Using Name-based Virtual Hosts</a></h2>
3726777f47ac4bba3e21b075905959bbea47e72eerikabele
3726777f47ac4bba3e21b075905959bbea47e72eerikabele<table class="related"><tr><th>Related Modules</th><th>Related Directives</th></tr><tr><td><ul><li><code class="module"><a href="/mod/core.html">core</a></code></li></ul></td><td><ul><li><code class="directive"><a href="/mod/core.html#documentroot">DocumentRoot</a></code></li><li><code class="directive"><a href="/mod/core.html#namevirtualhost">NameVirtualHost</a></code></li><li><code class="directive"><a href="/mod/core.html#serveralias">ServerAlias</a></code></li><li><code class="directive"><a href="/mod/core.html#servername">ServerName</a></code></li><li><code class="directive"><a href="/mod/core.html#serverpath">ServerPath</a></code></li><li><code class="directive"><a href="/mod/core.html#virtualhost">VirtualHost</a></code></li></ul></td></tr></table>
3726777f47ac4bba3e21b075905959bbea47e72eerikabele
3726777f47ac4bba3e21b075905959bbea47e72eerikabele <p>To use name-based virtual hosting, you must designate the IP
3726777f47ac4bba3e21b075905959bbea47e72eerikabele address (and possibly port) on the server that will be accepting
3726777f47ac4bba3e21b075905959bbea47e72eerikabele requests for the hosts. This is configured using the <code class="directive"><a href="/mod/core.html#namevirtualhost">NameVirtualHost</a></code> directive.
3726777f47ac4bba3e21b075905959bbea47e72eerikabele In the normal case where any and all IP addresses on the server should
3726777f47ac4bba3e21b075905959bbea47e72eerikabele be used, you can use <code>*</code> as the argument to
3726777f47ac4bba3e21b075905959bbea47e72eerikabele <code>NameVirtualHost</code>. Note that mentioning an IP address in a
3726777f47ac4bba3e21b075905959bbea47e72eerikabele <code>NameVirtualHost</code> directive does not automatically make the
3726777f47ac4bba3e21b075905959bbea47e72eerikabele server listen to that IP address. See <a href="/bind.html">Setting
3726777f47ac4bba3e21b075905959bbea47e72eerikabele which addresses and ports Apache uses</a> for more details. In addition,
3726777f47ac4bba3e21b075905959bbea47e72eerikabele any IP address specified here must be associated with a network interface
3726777f47ac4bba3e21b075905959bbea47e72eerikabele on the server.</p>
3726777f47ac4bba3e21b075905959bbea47e72eerikabele
3726777f47ac4bba3e21b075905959bbea47e72eerikabele <p>The next step is to create a <code class="directive"><a href="/mod/core.html#virtualhost">&lt;VirtualHost&gt;</a></code> block for
3726777f47ac4bba3e21b075905959bbea47e72eerikabele each different host that you would like to serve. The argument to the
3726777f47ac4bba3e21b075905959bbea47e72eerikabele <code>&lt;VirtualHost&gt;</code> directive should be the same as the
3726777f47ac4bba3e21b075905959bbea47e72eerikabele argument to the <code>NameVirtualHost</code> directive (ie, an IP
3726777f47ac4bba3e21b075905959bbea47e72eerikabele address, or <code>*</code> for all addresses). Inside each
3726777f47ac4bba3e21b075905959bbea47e72eerikabele <code>&lt;VirtualHost&gt;</code> block, you will need at minimum a /
3726777f47ac4bba3e21b075905959bbea47e72eerikabele <code class="directive"><a href="/mod/core.html#servername">ServerName</a></code> directive to
3726777f47ac4bba3e21b075905959bbea47e72eerikabele designate which host is served and a <code class="directive"><a href="/mod/core.html#documentroot">DocumentRoot</a></code> directive to
3726777f47ac4bba3e21b075905959bbea47e72eerikabele show where in the filesystem the content for that host lives.</p>
3726777f47ac4bba3e21b075905959bbea47e72eerikabele
3726777f47ac4bba3e21b075905959bbea47e72eerikabele <p>If you are adding virtual hosts to an existing web server, you
d03dd7e22aeb4b6940fb43d02db1233c1bedd799nd must also create a &lt;VirtualHost&gt; block for the existing host.
d03dd7e22aeb4b6940fb43d02db1233c1bedd799nd The <code>ServerName</code> and <code>DocumentRoot</code> included in
3726777f47ac4bba3e21b075905959bbea47e72eerikabele this virtual host should be the same as the global
3726777f47ac4bba3e21b075905959bbea47e72eerikabele <code>ServerName</code> and <code>DocumentRoot</code>. List this
3726777f47ac4bba3e21b075905959bbea47e72eerikabele virtual host first in the configuration file so that it will act as
3726777f47ac4bba3e21b075905959bbea47e72eerikabele the default host.</p>
3726777f47ac4bba3e21b075905959bbea47e72eerikabele
3726777f47ac4bba3e21b075905959bbea47e72eerikabele <p>For example, suppose that you are serving the domain
3726777f47ac4bba3e21b075905959bbea47e72eerikabele <code>www.domain.tld</code> and you wish to add the virtual host
3726777f47ac4bba3e21b075905959bbea47e72eerikabele <code>www.otherdomain.tld</code>, which points at the same IP address.
3726777f47ac4bba3e21b075905959bbea47e72eerikabele Then you simply add the following to <code>httpd.conf</code>:</p>
3726777f47ac4bba3e21b075905959bbea47e72eerikabele
3726777f47ac4bba3e21b075905959bbea47e72eerikabele <div class="example"><pre>
3726777f47ac4bba3e21b075905959bbea47e72eerikabele NameVirtualHost *
3726777f47ac4bba3e21b075905959bbea47e72eerikabele
3726777f47ac4bba3e21b075905959bbea47e72eerikabele &lt;VirtualHost *&gt;
3726777f47ac4bba3e21b075905959bbea47e72eerikabele ServerName www.domain.tld
3726777f47ac4bba3e21b075905959bbea47e72eerikabele DocumentRoot /www/domain
3726777f47ac4bba3e21b075905959bbea47e72eerikabele &lt;/VirtualHost&gt;
d03dd7e22aeb4b6940fb43d02db1233c1bedd799nd
d03dd7e22aeb4b6940fb43d02db1233c1bedd799nd &lt;VirtualHost *&gt;
3726777f47ac4bba3e21b075905959bbea47e72eerikabele ServerName www.otherdomain.tld
3726777f47ac4bba3e21b075905959bbea47e72eerikabele DocumentRoot /www/otherdomain
3726777f47ac4bba3e21b075905959bbea47e72eerikabele &lt;/VirtualHost&gt;
3726777f47ac4bba3e21b075905959bbea47e72eerikabele</pre></div>
3726777f47ac4bba3e21b075905959bbea47e72eerikabele
3726777f47ac4bba3e21b075905959bbea47e72eerikabele <p>You can alternatively specify an explicit IP address in place of
3726777f47ac4bba3e21b075905959bbea47e72eerikabele the * in both the <code>NameVirtualHost</code> and
3726777f47ac4bba3e21b075905959bbea47e72eerikabele <code>&lt;VirtualHost&gt;</code> directives.</p>
3726777f47ac4bba3e21b075905959bbea47e72eerikabele
3726777f47ac4bba3e21b075905959bbea47e72eerikabele <p>Many servers want to be accessible by more than one name. This is
3726777f47ac4bba3e21b075905959bbea47e72eerikabele possible with the <code class="directive"><a href="/mod/core.html#serveralias">ServerAlias</a></code>
3726777f47ac4bba3e21b075905959bbea47e72eerikabele directive, placed inside the &lt;VirtualHost&gt; section. For
3726777f47ac4bba3e21b075905959bbea47e72eerikabele example if you add this to the first &lt;VirtualHost&gt; block
above</p>
<div class="example"><p><code>
ServerAlias domain.tld *.domain.tld
</code></p></div>
<p>then requests for all hosts in the <code>domain.tld</code> domain
will be served by the <code>www.domain.tld</code> virtual host. The
wildcard characters * and ? can be used to match names. Of course,
you can't just make up names and place them in <code>ServerName</code>
or <code>ServerAlias</code>. You must first have your DNS server
properly configured to map those names to an IP address associated
with your server.</p>
<p>Finally, you can fine-tune the configuration of the virtual hosts
by placing other directives inside the
<code>&lt;VirtualHost&gt;</code> containers. Most directives can be
placed in these containers and will then change the configuration only
of the relevant virtual host. To find out if a particular directive
is allowed, check the <a href="/mod/directive-dict.html#Context">Context</a> of the
directive. Configuration directives set in the <em>main server
context</em> (outside any <code>&lt;VirtualHost&gt;</code> container)
will be used only if they are not overriden by the virtual host
settings.</p>
<p>Now when a request arrives, the server will first check if it is
using an IP address that matches the <code>NameVirtualHost</code>. If
it is, then it will look at each <code>&lt;VirtualHost&gt;</code>
section with a matching IP address and try to find one where the
<code>ServerName</code> or <code>ServerAlias</code> matches the
requested hostname. If it finds one, then it uses the configuration
for that server. If no matching virtual host is found, then
<strong>the first listed virtual host</strong> that matches the IP
address will be used.</p>
<p>As a consequence, the first listed virtual host is the
<em>default</em> virtual host. The <code>DocumentRoot</code> from the
<em>main server</em> will <strong>never</strong> be used when an IP
address matches the <code>NameVirtualHost</code> directive. If you
would like to have a special configuration for requests that do not
match any particular virtual host, simply put that configuration in a
<code>&lt;VirtualHost&gt;</code> container and list it first in the
configuration file.</p>
</div><div class="top"><a href="#page-header"><img alt="top" src="/images/up.gif" /></a></div><div class="section"><h2><a name="" id="">Compatibility with Older Browsers</a></h2>
<p>As mentioned earlier, there are some clients
who do not send the required data for the name-based virtual
hosts to work properly. These clients will always be sent the
pages from the first virtual host listed for that IP address
(the <cite>primary</cite> name-based virtual host).</p>
<p>There is a possible workaround with the <code class="directive"><a href="/mod/core.html#serverpath">ServerPath</a></code>
directive, albeit a slightly cumbersome one:</p>
<p>Example configuration:</p>
<div class="example"><p><code>
NameVirtualHost 111.22.33.44<br />
<br />
&lt;VirtualHost 111.22.33.44&gt;<br />
ServerName www.domain.tld<br />
ServerPath /domain<br />
DocumentRoot /web/domain<br />
&lt;/VirtualHost&gt;<br />
</code></p></div>
<p>What does this mean? It means that a request for any URI
beginning with "<code>/domain</code>" will be served from the
virtual host <code>www.domain.tld</code> This means that the
pages can be accessed as
<code>http://www.domain.tld/domain/</code> for all clients,
although clients sending a <code>Host:</code> header can also
access it as <code>http://www.domain.tld/</code>.</p>
<p>In order to make this work, put a link on your primary
virtual host's page to
<code>http://www.domain.tld/domain/</code> Then, in the virtual
host's pages, be sure to use either purely relative links
(<em>e.g.</em>, "<code>file.html</code>" or
"<code>/icons/image.gif</code>" or links containing the
prefacing <code>/domain/</code> (<em>e.g.</em>,
"<code>http://www.domain.tld/domain/misc/file.html</code>" or
"<code>/domain/misc/file.html</code>").</p>
<p>This requires a bit of discipline, but adherence to these
guidelines will, for the most part, ensure that your pages will
work with all browsers, new and old.</p>
</div></div><div id="footer"><p class="apache">Maintained by the <a href="http://httpd.apache.org/docs-project/">Apache HTTP Server Documentation Project</a></p><p class="menu"><a href="/mod/">Modules</a> | <a href="/mod/directives.html">Directives</a> | <a href="/faq/">FAQ</a> | <a href="/glossary.html">Glossary</a> | <a href="/sitemap.html">Sitemap</a></p></div></body></html>