--On Monday, 02 April, 2007 09:32 -0700 Lisa Dusseault
On Mar 31, 2007, at 5:24 PM, John C Klensin wrote:
having to prohibit IPv6 (or IPv6-without-IPv4) in 2007
seems strange and very unfortunate. RFC3974, which does
derive from operational experience, doesn't shed a lot of
light on this: a quick summary is that IPv4-only is ok,
IPv6-only is ok, but, for mixtures or unknown destinations,
any IPv6 host had better be running dual-stack with some IPv4
MX records. That document contains a few statements that I
believe to be serious errors (perhaps the reason it was
published as an independent submission with strong
disclaimers), but it is at least a thoughtful attempt to
explore the problem.
I need consensus advice on this one.
Do we have the right IPv6 experience on the list for this one?
I'm not sure who to consult, but there may be experts not on
this list (please pipe up if you are an expert and on this
list already, or if you have a suggestion who to consult).
There's probably relevant operational experience out there
I know I'm not an expert, but, given Frank's response to my
note, I would claim that there is some small evidence that I've
thought about it enough to be able to identify some of the nasty
Certainly there is expertise out there, but the answers may not
be clear even then. For example, the authors of RFC 3974
thought about the issues and apparently ran some production
systems. They then produced a draft based on their experience
that they community apparently didn't consider solid enough to
publish as a BCP and hence sent down the "informational" track
with a rather strong disclaimer.
Let me offer a hypothesis: We could go out and round up the
necessary expertise and the people with the right experience to
upgrade 3974 into something that could be published as a BCP or
on the Standards Track. It is probably worth doing, but it
wouldn't be quick because, probably, everyone with the
experience is busy (e.g., in my case, I don't think I could
spend significant energy on it until after we get EAI put to
bed, but I may not be critical). That turns into a question to
you, Chris, and the people who are really anxious to get 2821bis
published: can we figure out a responsible way to finesse this
in RFC2821bis and move it forward? Or do we need to derail
2821bis until we can resolve the IPv6 issues and write them up,
either in the document or in something that it can reference?