Re: (ngtrans) Joint DNSEXT & NGTRANS summary

[Robert Elz <kre@munnari.OZ.AU>]

    Date:        Wed, 15 Aug 2001 20:40:10 +0900
    From:        Jun-ichiro itojun Hagino <itojun@iijlab.net>
    Message-ID:  <20010815114010.CA9C17BA@starfruit.itojun.org>

  | 	you should care about this.

Why?

  |	there's no guarantee that AAAA synthesis
  | 	happen between end client and master/slave nameservers.  AAAA will
  | 	leak from leaf to the core.

Yes.   That doesn't tell me why I need to care.   People send queries
for all kinds of RR types that I don't have in my zone files, my
servers return NO DATA responses (no error, no answer).  Perfectly
normal.   That's what is likely to happen if they request an AAAA and
all I have is A6.   (Just maybe I'll do AAAA synthesis for random people
in the very early days).

Exactly why is this a problem to care about?

  | 	if people query both AAAA and A6, there will be more delays.

Yes, so they shouldn't.   End nodes can do AAAA to their back end.
The back end should do A6 only, and synthesise the AAAA.   No extra delays.

  | 	you seem to be assuming that there's some AAAA synthesis server
  | 	between IPv6 end node and nameservers.  your assumption does not hold,
  | 	especially during the transition period.

Right now it doesn't, no, it will take a little while to get them
installed everywhere if we decide on A6 now.

  |     because the assumption
  | 	does not hold, zone admins need to maintain AAAA records too.

No, I can use A records as backup.   They backup both the peers that
only know about AAAA, and the ones that don't know IPv6 at all.   We all
agree that IPv4 is still going to be needed for a while yet, so it is
just fine with me if peers who cannot handle A6 at all simply use IPv4.
That will work.

If the remote end wants to use IPv6, then it can install a synthesis
server for its AAAA only nodes, and the A6 records will work fine.

We can do this, because right now IPv4 works, and is a backup that we
need to have anyway - so it is just fine to simply toss out all the
AAAA records and replace them with A6.   Nothing is going to break
because of that.

We won't be able to do that when we start getting native IPv6 nets though,
which is why if this change is ever to be made, it needs to be made very
soon - otherwise never.

kre