Adding IPv6 to Ubuntu systems

To bind IPv6 IPs to your Ubuntu server, edit your /etc/network/interfaces file and add the following lines to the bottom.

#IPV6 configuration
iface eth1 inet6 static
pre-up modprobe ipv6
address 2607:f0d0:2001:0000:0000:0000:0000:0010
netmask 64
gateway 2607:f0d0:2001:0000:0000:0000:0000:0001

The first line tells the system which interface to use IPv6 on.
The second line tells the system to load the module for IPv6.
The third line gives the IPv6 address.
The fourth line defines the netmask for the IPv6 subnet.
The fifth line defines the default gateway for the IPv6 subnet.

Read more http://blogmee.info/index.php/adding-ipv6-to-ubuntu-systems/