4in6

IPv6 transition mechanisms
Standards Track
4in6 6in4 6over4 DS-Lite 6rd 6to4 ISATAP NAT64 / DNS64 Teredo SIIT
Experimental
TSP
Informational
Tunnel broker IVI TRT
Drafts
4rd AYIYA dIVI MAP
Deprecated
NAT-PT NAPT-PT

4in6 refers to tunneling of IPv4 in IPv6. It is an Internet interoperation mechanism allowing Internet Protocol version 4 (IPv4) to be used in an IPv6 only network. 4in6 uses tunneling to encapsulate IPv4 traffic over configured IPv6 tunnels as defined in RFC 2473. 4in6 tunnels are usually manually configured but they can be automated using protocols such as TSP to allow easy connection to a tunnel broker.

References

RFC 2473, Generic Packet Tunneling in IPv6 Specification, A. Conta and S. Deering 1998