IPv6/ubuntu/gogoc/設定について、ここに記述してください。

https://wiki.ubuntu.com/IPv6 

Configure your Ubuntu box as a IPv6 router

    Edit /etc/sysctl.conf 

Uncomment the line which contains net.ipv6.conf.default.forwarding=1. This is a common step to enable IPv6 routing.

You can learn how to install and enable DHCPv6 on your network here.

Alternatively, if you want to use radvd which will advertise your prefix and let the network's systems select their own IP address:

    Install radvd 

sudo aptitude install radvd

    Edit /etc/radvd.conf (see following sample) 

Note: If the computer is only routing IPv6, then only uncomment net.ipv6.conf.default.forwarding=1 and leave the IPv4 stuff unchanged.

Note: /etc/radvd.conf: This file does not exist after a fresh install. You can look at the sample configuration files in usr/share/doc/radvd/examples/ for further studies.

Sample /etc/radvd.conf:

interface eth0
{
   AdvSendAdvert on;
   prefix 2001:ffff:ffff::/64
   {
        AdvOnLink on;
        AdvAutonomous on;
   };
};

eth0 is the interface which is used for the Router Advertising messages (RA's). If you are not sure about the interface, check with ifconfig on the command line.

The prefix you have to take from the information given by the Sixxs or Hurricane Electric stuff.

Restart the router advertising daemon to propagate your IPv6 address space

sudo /etc/init.d/radvd restart

Now router should automatically send "Router Advertising Messages" to your network and your IPv6 clients should auto configure them self.