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Re: Follow-up work on NAT-PT
On 29 okt 2007, at 21:40, Brian E Carpenter wrote:
I'm interested to hear your thoughts on IPv6-only hosts (as opposed
to dual-stack hosts) during the IPv4-to-IPv6 transition period. The
work I've been doing up till now has made a fundamental assumption
that we would see only v4-only and dual-stack hosts, assuming that
only post IPv4 shutdown would we see an emergence of IPv6-only
devices.
The IAB request specifically asks for a solution for IPv6-only
hosts. It's long been my view that the primary coexistence strategy
must be dual-stack, but I'm trying to answer the IAB's question.
The problem with dual stack is that it doesn't solve anything: you
still need just as much IPv4 as when running IPv4-only. Dual stack is
important for server so that both IPv4-only and IPv6-only clients can
use the service, but we need to move towards a situation where it's
possible for a regular end-user PC to run IPv6-only without much loss
of functionality (if any).
Finally, from my reading the usefulness of SHANTI is only where the
IPv6-only host has an application that appreciates IPv4 parameters
(port and address) or the translation itself. Do we expect
application developers to widely cater for this scenario, or to
make the assumption that "if IPv4 matters we should use the IPv4
stack"?
No, SHANTI will work out of the box for any application that runs
through a traditional NAT or NAPT without problems *and* has been
upgraded to AF_INET6 sockets.
Ugh! Mixing IPv6 and NAT is something that I'd really like to avoid.
On monday I'll wrestle with xml2rfc once again, and if successful,
I'll have a draft that suggests a slightly different way of doing
this. (If anyone wants to mail me something I can use as an up-to-date
xml2rfc template that would be much appreciated.)