<p>To use name-based virtual hosting, you must designate the IP
address (and possibly port) on the server that will be accepting
requests for the hosts. This is configured using the <code class="directive"><a href="../mod/core.html#namevirtualhost">NameVirtualHost</a></code> directive.
In the normal case where any and all IP addresses on the server should
be used, you can use <code>*</code> as the argument to <code class="directive"><a href="../mod/core.html#namevirtualhost">NameVirtualHost</a></code>. If you're planning to use
multiple ports (e.g. running SSL) you should add a Port to the argument,
such as <code>*:80</code>. Note that mentioning an IP address in a
<code class="directive"><a href="../mod/core.html#namevirtualhost">NameVirtualHost</a></code> directive does not
automatically make the server listen to that IP address. See
<a href="../bind.html">Setting which addresses and ports Apache uses</a>
for more details. In addition, any IP address specified here must be
associated with a network interface on the server.</p>
<p>The next step is to create a <code class="directive"><a href="../mod/core.html#virtualhost"><VirtualHost></a></code> block for
each different host that you would like to serve. The argument to the
should be the same as the argument to the <code class="directive"><a href="../mod/core.html#namevirtualhost">NameVirtualHost</a></code> directive (ie, an IP address,
or <code>*</code> for all addresses). Inside each <code class="directive"><a href="../mod/core.html#virtualhost"><VirtualHost></a></code> block, you will need at minimum a
<code class="directive"><a href="../mod/core.html#servername">ServerName</a></code> directive to designate
which host is served and a <code class="directive"><a href="../mod/core.html#documentroot">DocumentRoot</a></code>
directive to show where in the filesystem the content for that host
lives.</p>
<div class="note"><h3>Main host goes away</h3>
<p>If you are adding virtual hosts to an existing web server, you
must also create a <code class="directive"><a href="../mod/core.html#virtualhost"><VirtualHost></a></code> block for the existing host. The <code class="directive"><a href="../mod/core.html#servername">ServerName</a></code> and <code class="directive"><a href="../mod/core.html#documentroot">DocumentRoot</a></code> included in this virtual host should be the
same as the global <code class="directive"><a href="../mod/core.html#servername">ServerName</a></code> and
<code class="directive"><a href="../mod/core.html#documentroot">DocumentRoot</a></code>. List this virtual
host first in the configuration file so that it will act as the default
host.</p>
</div>
<p>For example, suppose that you are serving the domain
<code>www.domain.tld</code> and you wish to add the virtual host
<code>www.otherdomain.tld</code>, which points at the same IP address.
Then you simply add the following to <code>httpd.conf</code>:</p>
<p>You can alternatively specify an explicit IP address in place of the
<code>*</code> in both the <code class="directive"><a href="../mod/core.html#namevirtualhost">NameVirtualHost</a></code> and <code class="directive"><a href="../mod/core.html#virtualhost"><VirtualHost></a></code> directives. For example, you might want to do this
in order to run some name-based virtual hosts on one IP address, and either
IP-based, or another set of name-based virtual hosts on another address.</p>
<p>Many servers want to be accessible by more than one name. This is
possible with the <code class="directive"><a href="../mod/core.html#serveralias">ServerAlias</a></code>
directive, placed inside the <code class="directive"><a href="../mod/core.html#virtualhost"><VirtualHost></a></code> section. For example in the first <code class="directive"><a href="../mod/core.html#virtualhost"><VirtualHost></a></code> block above, the
<code class="directive"><a href="../mod/core.html#serveralias">ServerAlias</a></code> directive indicates that
the listed names are other names which people can use to see that same
web site:</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 <code>*</code> and <code>?</code> can be used to match names.
Of course, you can't just make up names and place them in <code class="directive"><a href="../mod/core.html#servername">ServerName</a></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 class="directive"><a href="../mod/core.html#virtualhost"><VirtualHost></a></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 class="directive"><a href="../mod/core.html#virtualhost"><VirtualHost></a></code>
container) will be used only if they are not overridden 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 class="directive"><a href="../mod/core.html#namevirtualhost">NameVirtualHost</a></code>. If it is, then it will look at each <code class="directive"><a href="../mod/core.html#virtualhost"><VirtualHost></a></code> section with a matching
IP address and try to find one where the <code class="directive"><a href="../mod/core.html#servername">ServerName</a></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 class="directive"><a href="../mod/core.html#documentroot">DocumentRoot</a></code> from
the <em>main server</em> will <strong>never</strong> be used when an IP
address matches the <code class="directive"><a href="../mod/core.html#namevirtualhost">NameVirtualHost</a></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 class="directive"><a href="../mod/core.html#virtualhost"><VirtualHost></a></code>
container and list it first in the configuration file.</p>
