> > Unless I've missed something recent, the IETF did not do a > lot of work > > on the scenario where IPv4 islands need to communicate over an IPv6 > > Internet, talking to both IPv4 and IPv6 services. > > It is called dual-stack. That seems to simply ignore the issue by saying, let there be IPv4 everywhere for those who need it. But if there are not enough addresses to grow the IPv4 infrastructure, you can't have IPv4 everywhere. > The big question of course is: what exact problem do you want > to solve? An IPv4 island, that is blissfully unaware of the IPv4 address crunch until far too late, wants to avoid changing their network but still maintain connectivity to both the IPv6 and the IPv4 Internet. They may have to connect to an IPv6 ISP (for instance if their IPv4 ISP goes bankrupt or they move an office location) or they may connect to an IPv4 ISP who peers with a dual-stack ISP or 6PE ISP. How do they continue to access all Internet services from their IPv4 island, regardless of whether or not the services are using IPv6 only? Note that this is rather similar to the question raised regarding the IPv4 outage at an IETF meeting. How does an IPv4 laptop user continue to function without interruption when only IPv6 Internet access is available at an IETF meeting? Assume that IPv4 wifi is functioning and that the user does not change anything on their laptop to accommodate the fact that connectivity is via IPv6. And include the scenario where the IPv4 user successfully accesses an arbitrary protocol server which is IPv6 only and has no A records in its DNS. > Stating "I want to connect from IPv4 to IPv6", can mean a lot > of things, is this HTTP? SMTP? or do you really want a > generic solution? A generic solution that will work for all TCP and UDP protocols. I don't believe that there is an IETF solution for this scenario which I expect to be a very common scenario specifically because transition to IPv6 is being triggered by an IPv4 address shortage whose effects will be felt first in the network core and ripple outward from there. --Michael Dillon _______________________________________________ Ietf@xxxxxxxx https://www1.ietf.org/mailman/listinfo/ietf