John C Klensin wrote:
Hector has tried to summarize the various positions, but his
note seems to comment on connectivity choices. I don't think
those choices are at issue. I don't believe they _can_ be an
issue in 2821bis because making special rules about connection
types would require updating RFC 3484.
John, it cross my mind that this should be my last statement on this.
I hope my over simplification does not lose its basic meaning.
I think the chart, summary I provided shows that the question we have
attempts to address how a IPv6 system should behavior. Not a IPv4 system.
It is the IPv6 system that needs to decide where it should look up A or
AAAA records. Not IPv4 systems.
Unless you don't think so, I don't think 2821bis is in any position to
begin describing how IPv6 should behave as far as what records and/or
order of lookups it should do. A first, AAAA second or vice versa,
information that both RFC 3484 and also 4083 attempt to address for IPv6
systems or hybrids. Not pure IPV4 systems and this is clearly described
in both documents. IPv4 only systems will behave only one way. This is
independent of a Dual Stack Node. Not Dual Stack SMTP Application
In short, IMV, 2821bis is still about IPv4 and I think the only thing
that we can even mention is to codify the fact that an incoming IPv6
still needs to be compatible with a 2821 IPv4 SMTP system.
--
Sincerely
Hector Santos, CTO
http://www.santronics.com
http://santronics.blogspot.com