<-
Apache > HTTP Server > Documentation > Version 2.5 > Virtual Hosts

Apache IP-based Virtual Host Support

See also

top

What is IP-based virtual hosting

IP-based virtual hosting is a method to apply different directives based on the IP address and port a request is received on. Most commonly, this is used to serve different websites on different ports or interfaces.

In many cases, name-based virtual hosts are more convenient, because they allow many virtual hosts to share a single address/port. See Name-based vs. IP-based Virtual Hosts to help you decide.

top

System requirements

As the term IP-based indicates, the server must have a different IP address/port combination for each IP-based virtual host. This can be achieved by the machine having several physical network connections, or by use of virtual interfaces which are supported by most modern operating systems (see system documentation for details, these are frequently called "ip aliases", and the "ifconfig" command is most commonly used to set them up), and/or using multiple port numbers.

In the terminology of Apache HTTP Server, using a single IP address but multiple TCP ports, is also IP-based virtual hosting.

top

How to set up Apache

There are two ways of configuring apache to support multiple hosts. Either by running a separate httpd daemon for each hostname, or by running a single daemon which supports all the virtual hosts.

Use multiple daemons when:

Use a single daemon when:

top

Setting up multiple daemons

Create a separate httpd installation for each virtual host. For each installation, use the Listen directive in the configuration file to select which IP address (or virtual host) that daemon services. e.g.

Listen 192.0.2.100:80

It is recommended that you use an IP address instead of a hostname (see DNS caveats).

top

Setting up a single daemon with virtual hosts

For this case, a single httpd will service requests for the main server and all the virtual hosts. The VirtualHost directive in the configuration file is used to set the values of ServerAdmin, ServerName, DocumentRoot, ErrorLog and TransferLog or CustomLog configuration directives to different values for each virtual host. e.g.

<VirtualHost 172.20.30.40:80>
    ServerAdmin webmaster@www1.example.com
    DocumentRoot "/www/vhosts/www1"
    ServerName www1.example.com
    ErrorLog "/www/logs/www1/error_log"
    CustomLog "/www/logs/www1/access_log" combined
</VirtualHost>

<VirtualHost 172.20.30.50:80>
    ServerAdmin "webmaster@www2.example.org"
    DocumentRoot "/www/vhosts/www2"
    ServerName www2.example.org
    ErrorLog "/www/logs/www2/error_log"
    CustomLog "/www/logs/www2/access_log" combined
</VirtualHost>

It is recommended that you use an IP address instead of a hostname in the <VirtualHost> directive (see DNS caveats).

Specific IP addresses or ports have precedence over their wildcard equivalents, and any virtual host that matches has precedence over the servers base configuration.

Almost any configuration directive can be put in the VirtualHost directive, with the exception of directives that control process creation and a few other directives. To find out if a directive can be used in the VirtualHost directive, check the Context using the directive index.

SuexecUserGroup may be used inside a VirtualHost directive if the suEXEC wrapper is used.

SECURITY: When specifying where to write log files, be aware of some security risks which are present if anyone other than the user that starts Apache has write access to the directory where they are written. See the security tips document for details.

top