Re: [DNSOP] The Larger Discussion on Differences in Response Drafts

[[e-mail]]

Hello,

> From: Tim Wicinski <[e-mail]>
> In Berlin we had two presentations on different methods of returning
> multiple responses:

> All of these documents are attempting to solve a larger problem in
> different ways.
> The end result is "Return Associated Answer" to the client.
> 
> The question is starting to coalesce around these two premises:

Is it true that the extensions are used both RD=1 (stub to full-service resolver)
and RD=0 (full-servicce resolver to authoritative) ?

> - Do we want to Server to PUSH any or all Associated Answers, or

> https://datatracker.ietf.org/doc/draft-wkumari-dnsop-multiple-responses/

Full-service resolvers need to preserve/cache EXTRA RR and all related
qname/qtype pairs. And then, they need to generate the same answers as
the authoritative servers.

Stub resolvers need to know/detect the full-service resolver support
the extension or not. Currently, stub resolvers send both A and AAAA
queries. We need to consider how to stop sending multiple queries.

> - Do we want the Client to PULL any or all Associated Answers, or

> https://datatracker.ietf.org/doc/draft-bellis-dnsext-multi-qtypes/

PULL (multiple queries) case, the stub resolver first sends QDCOUNT>1
or with new EDNS options, and if it received FORMERR / ignored, it can
switch to traditional mode.

For both cases, we should take care of the nonexistence of additional
names or additional types. The associated answers may need NSEC RR.

# Non-existent pseudo RDATA may be useful, however, RDLENGTH=0 is not reserved.

-- 
Kazunori Fujiwara, JPRS <[e-mail]>