Subject: Re: empty answers

From: Rob Austein <[email-masked]>
Date: Tue, 18 Feb 2003 13:36:16 -0500

At Tue, 18 Feb 2003 11:28:40 +0800, Ed Lewis wrote:
> 
> When was the last time a completely empty answer (w/RCODE=0) was 
> intentionally implemented?
> 
> E.g., a response to a query (in which the QCLASS and QNAME exist but 
> without a match for the QTYPE) that had neither a SOA RR nor a NXT RR 
> in the authority section?

I can't answer your question about "when", but for what it's worth:

This is a legitimate response for an authoritative-only name server to
send when asked about a zone for which it knows absolutely nothing.

If I assume that you meant "NS" rather than "NXT", it's still
legitimate, but less common, since it would only be given out by the
above name server when it had no root hints to hand out.  This is a
completely legitimate configuration, but not that common, due to
implementations that become despondant upon discovering that they have
no root hints and chose to reply with RCODE=2.

--
to unsubscribe send a message to [email-masked] with
the word 'unsubscribe' in a single line as the message text body.
archive: <http://ops.ietf.org/lists/namedroppers/>

---

From: [email-masked]
Date: Wed, 19 Feb 2003 08:15:16 +1100

> no root hints and chose to reply with RCODE=2.

	You missed the point of the question which was.  What was the
	last version of each vendors software to NOT return SOA for
	a NOERROR NODATA response.

	BIND 4.9.5 enabled sending of SOA for NOERROR NODATA.  It also
	enabled sending of SOA for cached negative responses.

	Mark
--
Mark Andrews, Internet Software Consortium
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: [email-masked]

---

From: Josh Littlefield <[email-masked]>
Date: Wed, 19 Feb 2003 12:55:57 -0500

Edward Lewis wrote:
> without a match for the QTYPE) that had neither a SOA RR nor a NXT RR in 
> the authority section?

It sounds like you're asking when vendors last shipped a server that 
produced Type 3 NO DATA responses, as defined in RFC 2308.

Cisco's currently shipping server will generate these.  Our next release, 
due shortly, will not.

  -josh

-- 
=====================================================================
Josh Littlefield                                  Cisco Systems, Inc.
[email-masked]                                      250 Apollo Drive
tel: 978-497-8378  fax: same               Chelmsford, MA  01824-3627

---

From: Edward Lewis <[email-masked]>
Date: Thu, 20 Feb 2003 13:42:01 +0800

At 12:55 -0500 2/19/03, Josh Littlefield wrote:
>>  E.g., a response to a query (in which the QCLASS and QNAME exist 
>>but without a match for the QTYPE) that had neither a SOA RR nor a 
>>NXT RR in the authority section?
>

Exactly...

>Cisco's currently shipping server will generate these.  Our next 
>release, due shortly, will not.

Thanks...
-- 
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Edward Lewis                                          +1-703-227-9854
ARIN Research Engineer

---

From: Edward Lewis <[email-masked]>
Date: Sat, 22 Feb 2003 11:24:05 +0800

Oh, a response with 0 RR's is legal, I've seen it in the past.  I was 
just wondering if it was still done.  I suppose the latter question 
is bogus, any specification would have to address empty answers (as 
they are are legal and, besides, there exists at least one process 
somewhere still capable of issuing them ;) ).