Brian - is it provable that no design for a follow-on to IPv4 would
have provided that backward compatibility? Or were there
architectural and engineering decisions that chose other features
over backward compatibility?
And, I guess I'll stop here as I'm rehashing a train that long ago
left the station...
- Ralph
On Oct 6, 2007, at Oct 6, 2007,4:14 PM, Brian E Carpenter wrote:
On 2007-10-05 09:12, Ralph Droms wrote:
Typo: should read IPv6 ~= IPv4+more_bits...
- Ralph
On Oct 4, 2007, at Oct 4, 2007,4:52 AM, Ralph Droms wrote:
Regarding transition:
On Sep 14, 2007, at Sep 14, 2007,3:43 PM, Dave Crocker wrote:
Unless I've missed something rather basic, in the case of IPv6,
very little
attention was paid to facilitating transition by maximizing
interoperability
with the IPv4 installed base.
Dave, I have to agree with you in this regard. We may have
achieved neither
significant new capabilities because IPv6 ~= IPv6+more_bits, nor
ease of
transition because transition wasn't thoroughly evaluated early
on in
the design process...
Ralph, that last assertion simply isn't true. Migration/transition/
co-existence was on the radar screen right from the start. The dual
stack model was chosen explicitly to allow for co-existence, and in
particular so that dual stack servers can serve both IPv4 and IPv6
clients, and that is running code.
There's a fundamental difficulty in having IPvX-only clients working
with IPvY-only servers except via application-level relays. It isn't
a consequence of design details of v4 and v6. I'm sure we could
have done better, but this was very definitely thought about.
Brian
_______________________________________________
Ietf@xxxxxxxx
https://www1.ietf.org/mailman/listinfo/ietf