Subject: (ngtrans) notes on A6 transition from AAAA (fwd)

From: Olafur Gudmundsson <[email-masked]>
Date: Sun, 25 Mar 2001 17:16:55 -0500 (EST)

Included is the "infamus" beer plan, on how to retire AAAA
everywhere but stub resolvers.
Please send all followup to namedroppers. 

	Olafur (DNSEXT WG co-chair)

ps: The peole haching this plan were Mark Andrews, Rob Austein, 
Alain Durand and Olafur Gudmundsson 

---------- Forwarded message ----------
Date: Sun, 18 Mar 2001 20:05:32 -0800
From: Alain Durand <[email-masked]>
To: [email-masked], [email-masked]
Subject: notes on A6 transition from AAAA

Transition from AAAA to A6

    Stub resolvers that ask for AAAA in queries with the RD bit turn ON
    will be returned AAAA answers.

    Resolvers that have send queries with RD bit OFF and ask for AAAA
    will be returned whatever is available, A6 or AAAA. Note that they
    SHOULD issues A6 queries in the first place.

    The entity that in its server role received a query with the RD bit
    turn ON and process that request in its resolver role issues
    A6 queries with the RD bit turned OFF is responsible for the
    systhesis of AAAA from A6 records. This entity MUST try first A6
    then MAY try AAAA queries to process the request.

    A authoritative server that only has AAAA entries and
    is asked for an A6 record MUST NOT synthesize A6 records
    from the AAAA ones. There is no restriction on populating both
    types, but it is strongly recommended against, and in such a case,
    both RRsets MUST be identical.

    If a query does not contain EDNS indicator, then any IPv6 addresses
    contain in additional data section MUST be AAAA.

    Root and TLD zones MUST only contain A6 with prefix of 0.

---

From: Bill Sommerfeld <[email-masked]>
Date: Mon, 26 Mar 2001 15:14:52 -0500

>     both RRsets MUST be identical.

This proposal does not formally define equivalence of AAAA and A6.

is this limited to zero-prefix A6, or does it include A6's with
non-zero prefixes which just happen to resolve to the same thing?
Based on Rob's "zero prefix A6 is equivalent to AAAA" slide, I assume
the former..

>     Root and TLD zones MUST only contain A6 with prefix of 0.

Following the "prohibit on primary load, grumble on secondary load,
allow through on cached queries" interpretation of the "be
conservative in what you send, and liberal in what you accept"
principle, I also assume that the "MUST"s on zone contents should be
be enforced only when loading a primary..

						- Bill

---

From: Rob Austein <[email-masked]>
Date: Mon, 26 Mar 2001 19:05:37 -0500

Date: Mon, 26 Mar 2001 15:14:52 -0500
   From: Bill Sommerfeld <[email-masked]>

Right.  There's still a bit of an open issue about what to do with
AAAA in the long run, perhaps declare it to be a form of meta query
for stub resolvers to use that means "get me an address, however
that's implemented this week, and just return me the bits please".

No, our theory was that we really didn't want synthesized A6 RRs at
all, full stop.  We're not trying for parallel mechanisms here, the
idea is that A6 would become the "real" data and AAAA would become the
way that certain clients chose to retrieve a simplified form of it.

As far as the software would be concerned, you're right.

We were, however, also recommending that these limits be enforced by
administrative policy for the root, TLDs, and other big public zones.
That's out of the IETF's scope, other than making the recommendation.