Iljitsch van Beijnum wrote: >> it is also necessary for servers on IPv6 only networks to be able to >> have presence on the public IPv4 internet. how else (for example) can >> IPv6-only networks accept incoming email from v4 only networks and/or >> serve web pages to v4-only clients? > > In principle I agree, but in practice all the services are available > on the IPv4-only internet so the ability for IPv6-only clients to > connect to IPv4-only servers will give us more than 90% of what users > need. in practice _today_ all of the services are available on the IPv4-only Internet. but that ceases to be the case once we run out of IPv4 addresses, or substantial services exist that are based on IPv6 (like access to mobile terminals). more generally, enterprises can't move their networks to IPv6 until they can make their services available to those who are still stuck with only IPv4. > NAT-PT doesn't have to address all corner cases. the cases you're thinking of as "corner cases" are more significant than you presume. >> yes you can do some of this with >> proxies, but it's infeasible to set up a proxy for every single >> application that needs to be able to communicate between these networks. > > You don't need per-application proxy implementations: you can simply > use the HTTP CONNECT method to ask the proxy to set up a TCP session > towards a destination (by IPv4/IPv6 address or FQDN) and then pipe > that session through the one you have to the proxy. Should work for > everything that uses TCP. See > > http://tools.ietf.org/id/draft-van-beijnum-v6ops-connect-method-00.txt yes, that's a very useful tool. Keith _______________________________________________ Ietf@xxxxxxxx https://www1.ietf.org/mailman/listinfo/ietf