Tunneling of IPv4 in IPv6
4in6 refers to tunneling of IPv4 in IPv6.[1][2] 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.[3] 4in6 tunnels are usually manually configured but they can be automated using protocols such as TSP to allow easy connection to a tunnel broker.[4]
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