NAT64
NAT64, defined in RFC 6146, is a stateful translation mechanism that lets an IPv6-only client reach an IPv4-only server without either side running dual-stack networking. A NAT64 device sits at the boundary between an IPv6-only network and the IPv4 internet: when an IPv6 client sends a packet addressed to a synthesized IPv6 address representing an IPv4 destination, the NAT64 device rewrites the packet into IPv4, tracks the resulting connection state, and translates the IPv4 server's replies back into IPv6 for the client. Because many IPv6-only clients typically share a limited pool of public IPv4 addresses on the far side, NAT64 usually also performs port translation, the same way ordinary IPv4-to-IPv4 NAT does. NAT64 only works for connections an IPv6 client initiates; an IPv4-only host on the internet cannot start a connection to a client behind it. NAT64 is normally deployed together with DNS64, which synthesizes the IPv6 addresses NAT64 needs by rewriting a destination's DNS answer -- without DNS64, a client would have no IPv6 address to send its IPv4-bound traffic to in the first place.
By AdminKit team, Netbase JSC · Updated