This guide is for current Ubuntu (12.x/13.x) and Debain (wheezy) sytems with Apache 2.2.
Last week my router decided to just get a IPv6 address and no normal IPv4. Except of Google and some other big sites nothing worked anymore. So I decided to enable IPv6 for my server.
It is easy to enable IPv6 and be ready for the future. Mostly all components are already IPv6 ready, but sadly big ISPs and some servers don't use it.