Binary package “miredo” in ubuntu precise

Teredo IPv6 tunneling through NATs

 The Teredo IPv6 tunneling protocol encapsulates IPv6 packets into UDP/IPv4
 datagrams, to allow hosts behind NAT devices to access the IPv6 Internet.
 Miredo is a Teredo client (as per RFC 4380): it can provide IPv6
 connectivity to a dual-stack IPv6/IPv4 host even if it is located behind a
 NAT. It can also operate as a Teredo relay which forwards IPv6 packets
 between the IPv6 Internet and remote Teredo clients.