FW: "no data known" vrs "host not found"

[Barry Margolin]

In article <a8dcva$el7 at pub3.rc.vix.com>, bert hubert  <ahu at ds9a.nl> wrote:
>In article <a8cnof$big at pub3.rc.vix.com>, Barry Margolin wrote:
>
>> Once you've performed an MX or A query, your server has information for the
>> name cached.  An ANY query will return whatever happens to be in the cache.
>
>I think that highly unlikely. 

Why?  Isn't that what's specified in the protocol?  Here's what RFC 1034
says:

         a. If the whole of QNAME is matched, we have found the
            node.

            If the data at the node is a CNAME, and QTYPE doesn't
            match CNAME, copy the CNAME RR into the answer section
            of the response, change QNAME to the canonical name in
            the CNAME RR, and go back to step 1.

            Otherwise, copy all RRs which match QTYPE into the
            answer section and go to step 6.

If QTYPE=ANY, all the RRs that happen to be in the cache match QTYPE.
You'll copy them into the answer, and won't perform a recursive query to
get anything else.

I don't think any of the DNS update RFC's (I just checked RFC 2181) have
changed the above interpretation.

-- 
Barry Margolin, barmar at genuity.net
Genuity, Woburn, MA
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