Virtual Hosts

Virtual hosting is the capability of a single system to server multiple web domain addresses. For example a single server could respond to requests for www.acme.com and www.coyote.com. This is clearly useful for public web sites, but virtual hosting is also an excellent technology to manage separate content for a single domain. For example: the administration interface and the user interfaces can be implemented as separate virtual hosts.

Configuration Directives

Virtual hosts are created by grouping configuration file directives within a VirtualHost directive block. Directives within the block apply only to the virtual host.

<VirtualHost 206.148.97.56>
    ServerName www.acme.com
    DocumentRoot /var/www/acmeDocs
    ...
</VirtualHost>

Before declaring a VirtualHost directive for name-based virtual hosting, you must use a NameVirtualHost directive. This specifies that the given IP address will use name-base hosting.

Name-base Virtual Hosts

Name-based virtual hosts allow multiple virtual hosts to share an IP address by using the Host HTTP header to distinguish which virtual host should service the request.

NOTE: Name-based virtual hosting cannot be used with the SSL protocol. You must use IP-based hosting.

Example

NameVirtualHost 206.148.97.56
<VirtualHost 206.148.97.56>
    ServerName www.acme.com
    DocumentRoot /var/www/acme
    ...
</VirtualHost>
<VirtualHost 206.148.97.56>
    ServerName www.coyote.com
    DocumentRoot /var/www/coyote
    ...
</VirtualHost>

In this example www.acme.com and www.coyote.com share the IP address 206.148.97.56. Note that the IP address specified by the NameVirtualHost directive must match the IP address in the VirtualHost directive. You may specify port numbers with the IP addresses if you require a port other than port 80.

WARNING: Some very old clients may not include the Host header in their HTTP request and so may not be able to use Name-based virtual hosting.

IP-based Virtual Hosts

IP-based virtual hosts allow multiple virtual hosts to be supported on a single server. Each IP-based virtual host consumes a separate IP address. The SSL protocol is supported with IP-based virtual hosting.

<VirtualHost 206.148.97.56>
    ServerName www.acme.com
    DocumentRoot /var/www/acme
    ...
</VirtualHost>
<VirtualHost 206.148.97.57>
    ServerName www.coyote.com
    DocumentRoot /var/www/coyote
    ...
</VirtualHost>

In this example www.acme.com and www.coyote.com are hosted.

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