dotcloud/docker — pull request #1016 by justinsb (2013-06-25 06:15:59+00:00)
Title: Basic support for IPv6 addresses

Assign an IPv6 address to a guest, if a (non-auto-generated) IPv6 address is assigned on docker0.

The IPv4 network remains "primary", and determines the assignment on subsequent networks. Thus, if you get 172.16.42.n, then you'll get ::n as your IPv6. So we only need to track the IPv4 assignments.

Likely you'll have to do this:
sudo sysctl -w net.ipv6.conf.all.forwarding=1

If you're using IPv6 neighbour discovery this is also needed (and should probably be done by docker in future, but this requires knowing what the 'external' network device is, which I think would require a docker configuration file):
sudo sysctl -w net.ipv6.conf.all.proxy_ndp=1
sudo ip -6 neigh add proxy ::2 dev eth0
sudo ip -6 neigh add proxy ::3 dev eth0
sudo ip -6 neigh add proxy ::4 dev eth0
...