Stateful NAT64: Network Address and Protocol Translation from IPv6 Clients to IPv4 Servers

This document describes stateful NAT64 translation, which allows IPv6-only clients to contact IPv4-only servers/peer using unicast UDP, TCP, or ICMP. One or more public IPv4 addresses assigned to a NAT64 translator are shared among several IPv6-only clients. When stateful NAT64 is used in conjunction with DNS64, no changes are required in either the IPv6 client or the IPv4 server/peer. At the time of writing this document, Stateful NAT64 has been widely and succesfully deployed across many networks in the Internet. This document obsoletes RFC6146.