Brian E Carpenter wrote: > Another +1 from me. > And with respect to the alleged mistake made 15 years ago, two facts > may help: You are saying it's not post-mortem but vivisection. OK. > 2. There is, mathematically and logically, no 'backwards compatible' > IP with bigger addresses than IPv4. Your statement is unfounded. Port restricted IP is the mathematical and logical IP with bigger *APPLICATION* address than IPv4 with full backward compatibility. > So the issue of interworking between legacy > IPv4-only systems and the world of bigger addresses is an > unavoidable fact of the physical universe. As the address space for transport and application layers is address+protocol+port, the space is identical with both IPv4 and port restricted IPv4. Thus, iterworking between IPv4 and PR-IPv4 just works. > Which is why BEHAVE is currently doing NAT64. With the existence of PR-IPv4, IPv6 including NAT64 is denied, mathematically and logically. Masataka Ohta _______________________________________________ Ietf mailing list Ietf@xxxxxxxx https://www.ietf.org/mailman/listinfo/ietf