1 <?xml version="1.0" encoding="ISO-8859-1"?>
2 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
3 <html xmlns="http://www.w3.org/1999/xhtml" lang="en" xml:lang="en"><head><!--
4 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
5 This file is generated from xml source: DO NOT EDIT
6 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
8 <title>Binding - Apache HTTP Server</title>
9 <link href="./style/css/manual.css" rel="stylesheet" media="all" type="text/css" title="Main stylesheet" />
10 <link href="./style/css/manual-loose-100pc.css" rel="alternate stylesheet" media="all" type="text/css" title="No Sidebar - Default font size" />
11 <link href="./style/css/manual-print.css" rel="stylesheet" media="print" type="text/css" />
12 <link href="./images/favicon.ico" rel="shortcut icon" /></head>
13 <body id="manual-page"><div id="page-header">
14 <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>
15 <p class="apache">Apache HTTP Server Version 2.1</p>
16 <img alt="" src="./images/feather.gif" /></div>
17 <div class="up"><a href="./"><img title="<-" alt="<-" src="./images/left.gif" /></a></div>
19 <a href="http://www.apache.org/">Apache</a> > <a href="http://httpd.apache.org/">HTTP Server</a> > <a href="http://httpd.apache.org/docs-project/">Documentation</a> > <a href="./">Version 2.1</a></div><div id="page-content"><div id="preamble"><h1>Binding</h1>
20 <p>Configuring Apache to listen on specific addresses and ports.</p>
22 <div id="quickview"><ul id="toc"><li><img alt="" src="./images/down.gif" /> <a href="#overview">Overview</a></li>
23 <li><img alt="" src="./images/down.gif" /> <a href="#ipv6">Special IPv6 Considerations</a></li>
24 <li><img alt="" src="./images/down.gif" /> <a href="#virtualhost">How This Works With Virtual Hosts</a></li>
25 </ul><h3>See also</h3><ul class="seealso"><li><a href="vhosts/">Virtual Hosts</a></li><li><a href="dns-caveats.html">DNS Issues</a></li></ul></div>
26 <div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div>
28 <h2><a name="overview" id="overview">Overview</a></h2>
31 <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><li><code class="module"><a href="./mod/mpm_common.html">mpm_common</a></code></li></ul></td><td><ul><li><code class="directive"><a href="./mod/core.html#virtualhost">VirtualHost</a></code></li><li><code class="directive"><a href="./mod/mpm_common.html#listen">Listen</a></code></li></ul></td></tr></table>
34 <p>When Apache starts, it binds to some port and address on
35 the local machine and waits for incoming requests. By default,
36 it listens to all addresses on the machine. However, it needs to
37 be told to listen on specific ports, or to listen on only selected
38 addresses, or a combination. This is often combined with the
39 Virtual Host feature which determines how Apache responds to
40 different IP addresses, hostnames and ports.</p>
42 <p>The <code class="directive"><a href="./mod/mpm_common.html#listen">Listen</a></code>
43 directive tells the server to accept
44 incoming requests only on the specified port or
45 address-and-port combinations. If only a port number is
46 specified in the <code class="directive"><a href="./mod/mpm_common.html#listen">Listen</a></code>
48 listens to the given port on all interfaces. If an IP address
49 is given as well as a port, the server will listen on the given
50 port and interface. Multiple Listen directives may be used to
51 specify a number of addresses and ports to listen on. The
52 server will respond to requests from any of the listed
53 addresses and ports.</p>
55 <p>For example, to make the server accept connections on both
56 port 80 and port 8000, use:</p>
58 <div class="example"><p><code>
63 <p>To make the server accept connections on two specified
64 interfaces and port numbers, use</p>
66 <div class="example"><p><code>
67 Listen 192.170.2.1:80<br />
68 Listen 192.170.2.5:8000
71 <p>IPv6 addresses must be surrounded in square brackets, as in the
72 following example:</p>
74 <div class="example"><p><code>
75 Listen [fe80::a00:20ff:fea7:ccea]:80
77 </div><div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div>
79 <h2><a name="ipv6" id="ipv6">Special IPv6 Considerations</a></h2>
82 <p>A growing number of platforms implement IPv6, and APR supports
83 IPv6 on most of these platforms, allowing Apache to allocate IPv6
84 sockets and handle requests which were sent over IPv6.</p>
86 <p>One complicating factor for Apache administrators is whether or
87 not an IPv6 socket can handle both IPv4 connections and IPv6
88 connections. Handling IPv4 connections with an IPv6 socket uses
89 IPv4-mapped IPv6 addresses, which are allowed by default on most
90 platforms but are disallowed by default on FreeBSD, NetBSD, and
91 OpenBSD in order to match the system-wide policy on those
92 platforms. But even on systems where it is disallowed by default, a
93 special configure parameter can change this behavior for Apache.</p>
95 <p>If you want Apache to handle IPv4 and IPv6 connections with a
96 minimum of sockets, which requires using IPv4-mapped IPv6 addresses,
97 specify the <code>--enable-v4-mapped</code> configure option and use
98 generic Listen directives like the following:</p>
100 <div class="example"><p><code>
104 <p>With <code>--enable-v4-mapped</code>, the Listen directives in the
105 default configuration file created by Apache will use this form.
106 <code>--enable-v4-mapped</code> is the default on all platforms but
107 FreeBSD, NetBSD, and OpenBSD, so this is probably how your Apache was
110 <p>If you want Apache to handle IPv4 connections only, regardless of
111 what your platform and APR will support, specify an IPv4 address on all
112 Listen directives, as in the following examples:</p>
114 <div class="example"><p><code>
115 Listen 0.0.0.0:80<br />
116 Listen 192.170.2.1:80
119 <p>If you want Apache to handle IPv4 and IPv6 connections on separate
120 sockets (i.e., to disable IPv4-mapped addresses), specify the
121 <code>--disable-v4-mapped</code> configure option and use specific Listen
122 directives like the following:</p>
124 <div class="example"><p><code>
129 <p>With <code>--disable-v4-mapped</code>, the Listen directives in the
130 default configuration file created by Apache will use this form.
131 <code>--disable-v4-mapped</code> is the default on FreeBSD, NetBSD, and
134 </div><div class="top"><a href="#page-header"><img alt="top" src="./images/up.gif" /></a></div>
135 <div class="section">
136 <h2><a name="virtualhost" id="virtualhost">How This Works With Virtual Hosts</a></h2>
139 <p>Listen does not implement Virtual Hosts. It only tells the
140 main server what addresses and ports to listen to. If no
141 <code class="directive"><a href="./mod/core.html#virtualhost"><VirtualHost></a></code>
142 directives are used, the server will behave
143 the same for all accepted requests. However,
144 <code class="directive"><a href="./mod/core.html#virtualhost"><VirtualHost></a></code>
145 can be used to specify a different behavior
146 for one or more of the addresses and ports. To implement a
147 VirtualHost, the server must first be told to listen to the
148 address and port to be used. Then a
149 <code class="directive"><a href="./mod/core.html#virtualhost"><VirtualHost></a></code> section
150 should be created for a specified address and port to set the
151 behavior of this virtual host. Note that if the
152 <code class="directive"><a href="./mod/core.html#virtualhost"><VirtualHost></a></code>
153 is set for an address and port that the
154 server is not listening to, it cannot be accessed.</p>
157 <p class="apache">Maintained by the <a href="http://httpd.apache.org/docs-project/">Apache HTTP Server Documentation Project</a></p>
158 <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>