By default, upon startup, the Apache server (httpd) listens to all addresses on the machine. However, you can bind Apache so that it listens only on specific ports and addresses. When combined with the Virtual Host feature, this determines how Apache responds to different IP addresses, hostnames and ports.

The Listen directive tells the server to accept incoming requests only on the specified port or address-and-port combinations. If only a port number is specified in the Listen directive, the server listens to the given port on all interfaces. If an IP address is given as well as a port, the server will listen on the given port and interface. Multiple Listen directives may be used to specify a number of addresses and ports to listen on. The server will respond to requests from any of the listed addresses and ports.

For example, to make the server accept connections on both port 80 and port 8000, use:

Listen 80
Listen 8000

To make the server accept connections on two specified interfaces and port numbers, use


IPv6 addresses must be surrounded in square brackets, as in the following example:

Listen [fe80::a00:20ff:fea7:ccea]:80


Special IPv6 Considerations

Apache can allocate sockets and handle requests sent over IPv6.

To handle both IPv4 and IPv6 connections with a minimum of sockets, using using only IPv4-mapped IPv6 addresses, specify the --enable-v4-mapped configure option and use generic Listen directives like the following:

Listen 80

--enable-v4-mapped is the default on all platforms but FreeBSD, NetBSD, and OpenBSD, so this is probably how your Apache was built.

If you want Apache to handle IPv4 connections only, regardless of what your platform and APR will support, specify an IPv4 address on all Listen directives, as in the following examples:


If you want Apache to handle IPv4 and IPv6 connections on separate sockets (i.e., to disable IPv4-mapped addresses), specify the --disable-v4-mapped configure option and use specific Listen directives like the following:

Listen [::]:80

With --disable-v4-mapped, the Listen directives in the default configuration file created by Apache will use this form. --disable-v4-mapped is the default on FreeBSD, NetBSD, and OpenBSD.


How This Works With Virtual Hosts

Listen does not implement Virtual Hosts. It only tells the main server what addresses and ports to listen to. If no <VirtualHost> directives are used, the server will behave the same for all accepted requests. However, <VirtualHost> can be used to specify a different behavior for one or more of the addresses and ports. To implement a VirtualHost, the server must first be told to listen to the address and port to be used. Then a <VirtualHost> section should be created for a specified address and port to set the behavior of this virtual host. Note that if the <VirtualHost> is set for an address and port that the server is not listening to, it cannot be accessed.