cc list trimed:
A couple of other considerations:
After IETF49, we held a ws that ran DNS on v6 transport. We tried
A6 & AAAA records in the context of the DNS root. Dales notes reflect
that FreeBSD's resolver was unable to recognise an A6 record when it
was "glue" for a root server. It was able to recognise a AAAA record.
This has not been rechecked to my knowledge.
This is also applicable between the servers for a zone. In a mixed
environment, it is possible to have servers running a variety of
code, from Bind4, Bind8, Bind9 and even some of the other genetic
varients (Microsoft, Lucent, PowerDNS, Akami, et.al.) Indeed, this
is one of the strengths of the DNS. And in such clusters, RR 28
is well known and is passed around. If an NS records "glue" is type
28, zone transfers will occur.
However nearly none of these versions/varients knows or supports
type 38. And given the strict checking, for coherancy, in most
of the recent code, if the glue for an NS is type 38, the zone
transfer will -fail-
That seems to indicate that if type 38 is to be used, all the servers
for the zone in which they reside must be running code from a single
branch. (the unknown RR type problem)
And there are indications that that particular branch is not all
that speedy. Some numbers I have seen indicate the QPS rate is
about 50% less than the previous branch. Are we really ready to
take that performance hit to gain A6 support?
Random idea...
Presume 10,000 v6 users today. If we give them AAAA now, and
agressively explore/test A6, on the experimental track for 12-18
months, we might presume there would be 1,000,000 v6 users by
then. That is still statistically "small" as an installed base
and we would have a much stronger case that A6 performance issues
are addressed, A4synth could be better understood, and operational
tools are available. If we put forth the effort, it should be
a no brainer to push it back on stds track and consider moving
AAAA to historic (sort of like RIPv1 is historic... people still
build it and use it. :)
The installed base is still small enough that we can make the
change... I think.
--bill
