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    <title>Setting which addresses and ports Apache uses</title>
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      <h3>Apache HTTP Server Version 1.3</h3>
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    <h1 align="CENTER">Setting which addresses and ports Apache
    uses</h1>
    <hr />
    When Apache starts, it connects to some port and address on the
    local machine and waits for incoming requests. By default, it
    listens to all addresses on the machine, and to the port as
    specified by the <tt>Port</tt> directive in the server
    configuration. However, it can be told to listen to more the
    one port, or to listen to only selected addresses, or a
    combination. This is often combined with the Virtual Host
    feature which determines how Apache responds to different IP
    addresses, hostnames and ports. 

    <p>There are two directives used to restrict or specify which
    addresses and ports Apache listens to.</p>

    <ul>
      <li><a href="#bindaddress">BindAddress</a> is used to
      restrict the server to listening to a single address, and can
      be used to permit multiple Apache servers on the same machine
      listening to different IP addresses.</li>

      <li><a href="#listen">Listen</a> can be used to make a single
      Apache server listen to more than one address and/or
      port.</li>
    </ul>

    <h3><a id="bindaddress" name="bindaddress">BindAddress</a></h3>
    <a href="mod/directive-dict.html#Syntax"
    rel="Help"><strong>Syntax:</strong></a> BindAddress <em>[ * |
    IP-address | hostname ]</em><br />
     <a href="mod/directive-dict.html#Default"
    rel="Help"><strong>Default:</strong></a> <code>BindAddress
    *</code><br />
     <a href="mod/directive-dict.html#Context"
    rel="Help"><strong>Context:</strong></a> server config<br />
     <a href="mod/directive-dict.html#Status"
    rel="Help"><strong>Status:</strong></a> Core 

    <p>Makes the server bind to just the specified address. If the
    argument is * (an asterisk), the server binds to all interfaces
    currently marked as up on the server. The port bound to is set
    with the <tt>Port</tt> directive. Only one BindAddress should
    be used.</p>

    <h3><a id="listen" name="listen">Listen</a></h3>
    <a href="mod/directive-dict.html#Syntax"
    rel="Help"><strong>Syntax:</strong></a> Listen <em>[ port |
    IP-address:port ]</em><br />
     <a href="mod/directive-dict.html#Default"
    rel="Help"><strong>Default:</strong></a>
    <code>none</code><br />
     <a href="mod/directive-dict.html#Context"
    rel="Help"><strong>Context:</strong></a> server config<br />
     <a href="mod/directive-dict.html#Status"
    rel="Help"><strong>Status:</strong></a> Core 

    <p><tt>Listen</tt> can be used instead of <tt>BindAddress</tt>
    and <tt>Port</tt>. It tells the server to accept incoming
    requests (to listen) on the specified port or address-and-port
    combination. If the first format is used, with a port number
    only, the server listens on the given port on all interfaces
    marked as up, instead of the port given by the <tt>Port</tt>
    directive. If an IP address is given as well as a port, the
    server will listen on the given port and interface.</p>

    <p>Multiple Listen directives may be used to specify a number
    of addresses and ports to listen to. The server will respond to
    requests from any of the listed addresses and ports.</p>

    <p>For example, to make the server accept connections on both
    port 80 and port 8000, use:</p>
<pre>
   Listen 80
   Listen 8000
</pre>
    To make the server accept connections on two specified
    interfaces and port numbers, use 
<pre>
   Listen 192.170.2.1:80
   Listen 192.170.2.5:8000
</pre>

    <h2>How this works with Virtual Hosts</h2>
    <tt>BindAddress</tt> and <tt>Listen</tt> do not implement
    Virtual Hosts. They tell the main Apache daemon process what
    addresses and ports to bind and listen on. If no
    &lt;VirtualHost&gt; directives are used, the server will behave
    the same for all accepted requests. However,
    &lt;VirtualHost&gt; can be used to specify a different behavior
    for one or more of the addresses and ports. To implement a
    VirtualHost, the server must: 

    <ul>
      <li>Be told to <tt>Listen</tt> to the desired address and
      port</li>

      <li>Have a &lt;VirtualHost&gt; section created for the
      specified address and port to set the behavior of this
      virtual host</li>
    </ul>
    Note that if the &lt;VirtualHost&gt; is set for an address and
    port that the server is not listening to, it cannot be
    accessed. 

    <h2>See also</h2>
    See also the documentation on <a href="vhosts/">Virtual
    Hosts</a>, <a href="mod/core.html#bindaddress">BindAddress
    directive</a>, <a href="mod/core.html#port">Port directive</a>,
    <a href="dns-caveats.html">DNS Issues</a> and <a
    href="mod/core.html#virtualhost">&lt;VirtualHost&gt;
    section</a>.     <hr />

    <h3 align="CENTER">Apache HTTP Server</h3>
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