--On April 13, 2006 8:13:27 AM +0930 Mark Smith <nanog@fa1c52f96c54f7450e1ffb215f29991e.nosense.org> wrote:

On Wed, 12 Apr 2006 17:27:54 -0400 Owen DeLong <owen@delong.com> wrote:

...

Apologies if anyone thinks this does not require coordination or is somehow not operational.

However, I have a situation where some nameservers for which I am responsible are receiving AAAA queries for hosts for which we are authoritative. We return the SOA only as it seems we are supposed to, but, we are seeing a significant delay before we get an A query back from the resolver, which, we believe represents a significant delay for the end user in getting to the web page in question.

I'd have thought you were supposed to return a record not found error, which would then cause the remote resolver to immediately revert to performing an A query.

Strangely enough, RFCs 1866, 3596, and 4074 seem to specifically say this is a bad thing.

...

Is there a better way to answer an AAAA query for a v4 only host? Is it permitted and/or desirable to return a 6to4 or IPv4-Mapped address? Is there some other preferable thing to return?

As long as you don't not respond, like doublelclick don't or didn't used to. Very frustrating waiting for AAAA queries to timeout before a page will fully load.

Nope... As near as I can tell, responding with SOA only data is the right thing to do. FWIW, that's what f.root-servers.net seems to do as well. Owen