Brian E Carpenter wrote: > > Martin, > > > One the one hand, the IETF was frowning upon NATs when they were > > developed outside of the IETF. But if you look at the IETFs > > (lack of) migration plan, the translation that you need in order > > to make old-IPv4 interoperate with new-IPv6, is actually worse than > > an IPv4 NAT. > > I'm sorry, but *any* coexistence between RFC791-IPv4-only hosts and > hosts that are numbered out of an address space greater than 32 bits > requires some form of address sharing, address mapping, and translation. > It doesn't matter what choice we made back in 1994. Once you get to the > point where you've run out of 32 bit addresses and not every node can > support >32 bit addresses, you have the problem. But what is your point? With a fully backwards compatible transparent addressing scheme, a much larger fraction of the nodes would have switched to actively use IPv6 many years ago. You would not have two distinct routing tables for two independent Internets, but a single routing table for a single Internet. And the first network interfaces that would be using >32-bit IP-addresses exclusively would have been networking equipment of ISPs that does not need to be IPv4-addressable by everyone and his dog anyway (that is not so much different from the /10 shared address space that CGNs will be using). The necessary changes to applications would be minimal, the "happy eyeballs" contortion completely unnecessary and the security assessment for an IPv6 enabled network *MUCH* simpler. -Martin _______________________________________________ Ietf mailing list Ietf@xxxxxxxx https://www.ietf.org/mailman/listinfo/ietf