Subject: [BEHAVE] DNS64 and CNAME/DNAME

From: Andrew Sullivan <[email-masked]>
Date: Fri, 23 Oct 2009 10:29:05 -0400

Dear colleagues,

When planning to make the changes we discussed at the interim, I
realised we have another issue that's currently not quite right.

We cover the case where the AAAA gets an error, and empty answer, or
AAAA in the answer, but we don't discuss the case where the answer
comes back as a CNAME or DNAME.  I propose the following text:

    If the response contains a CNAME or a DNAME, then the CNAME or
    DNAME chain is followed until the first terminating A or AAAA
    record is reached.  This may require the DNS64 to ask for an A
    record, in case the response to the original AAAA query is a CNAME
    or DNAME without an AAAA record to follow.  The resulting AAAA or
    A record is treated like any other AAAA or A case, as appropriate.

    When assembling the answer section, the original CNAME or DNAME
    RR is included as part of the answer, and the synthetic AAAA, if
    appropriate, is included. 

Ok?  The idea here is that we don't want to hand back a CNAME answer
with only an A in it, because the end node will not be able to use it.
So we do various queries until we get an address we can either pass
back unchanged, or an address that we can use as the basis for
synthesis.  The alternative, I suppose, is to return to the client the
CNAME or DNAME answer to the AAAA answer, without any address data if
there's no AAAA record or if the AAAA is in the exclusion set that we
determined on Wednesday we want to add.

Thoughts?

A

-- 
Andrew Sullivan
[email-masked]
Shinkuro, Inc.

---

From: Andrew Sullivan <[email-masked]>
Date: Fri, 23 Oct 2009 11:19:44 -0400

Also, I should have mentioned that I'm keen to make the Monday
deadline, so unless I hear objections I'll plan to go ahead with this.

Best,

A

On Fri, Oct 23, 2009 at 10:29:05AM -0400, Andrew Sullivan wrote:
> _______________________________________________
> Behave mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/behave

-- 
Andrew Sullivan
[email-masked]
Shinkuro, Inc.