> From: Harald Tveit Alvestrand <harald@xxxxxxxxxxxxx> >> Let's assume ... that a large part of the Internet is going to >> continue to be IPv4-only. So, what's the functional difference between: >> - A host which has an IPv6 only address, which it cannot use .. to >> comunicate directly with IPv4-only hosts out on the global Internet. >> - A host which has an IPv4 local-only address, which it cannot use >> .. to comunicate directly with other IPv4 hosts out on the global >> Internet. > that the former can communicate with all other nodes with globally > reachable IPv6 addresses, without having to borrow a global IPv4 > address to do so? > ... but it *is* a functional difference, and that was what you asked > for, Noel.... That an IPv6 host could communicate with other IPv6 hosts without use of a borrowed IPv4 address (assuming contiguous IPv6 packet tranmission connectivity of some sort) is (or ought to be) obvious - but unrelated to the point I was making with my rhetorical question. The point of said question being, as you are no doubt aware, to shed light on the exact question you posed: "whether [there] is a *significant* functional difference". I too left it (and will leave it now) as an exercise for the reader to figure out. Noel _______________________________________________ Ietf@xxxxxxxx https://www1.ietf.org/mailman/listinfo/ietf