Apache IPv6 Configuration: Dual Stacked IPv4 & IPv6 Virtual Hosts

To configure Apache to support both IPv4 and IPv6 virtual hosts, you can use the following steps:

1. Make sure that Apache is compiled with IPv6 support. To do this, check that the --enable-v6 option was passed to the ./configure script when Apache was compiled.

2. Make sure that your system has IPv6 support enabled. On most systems, this can be done by editing the /etc/sysctl.conf file and setting the net.ipv6.conf.all.disable_ipv6 parameter to 0. Then, run the sysctl -p command to apply the changes.

3. Add the Listen directive to your Apache configuration file. To listen on both IPv4 and IPv6 addresses, you can use the following directive:

Listen *:80

This will listen on all available IPv4 and IPv6 addresses on port 80.

4. Create separate virtual host configurations for your IPv4 and IPv6 virtual hosts. For example, to create an IPv4 virtual host, you can use the following configuration:

<VirtualHost *:80>
    ServerName example.com
    DocumentRoot /var/www/html
</VirtualHost>

To create an IPv6 virtual host, you can use the following configuration:

<VirtualHost [::]:80>
    ServerName example.com
    DocumentRoot /var/www/html
</VirtualHost>

Note that you will need to replace example.com with the actual domain name of your virtual host, and /var/www/html with the actual document root for your virtual host.

5. Restart Apache to apply the changes.

It's worth noting that you may need to configure your DNS records to point to both the IPv4 and IPv6 addresses of your virtual hosts. This will allow clients to connect to your virtual hosts using either IPv4 or IPv6 addresses.