[dnsext] MaraDNS and NXDOMAIN/NOERROR on non-terminal nodes

Sam Trenholme <strenholme.usenet@gmail.com> Sat, 23 April 2011 19:11 UTC

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Date: Sat, 23 Apr 2011 14:11:40 -0500
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From: Sam Trenholme <strenholme.usenet@gmail.com>
To: dnsext@ietf.org
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Cc: johnl@iecc.com
Subject: [dnsext] MaraDNS and NXDOMAIN/NOERROR on non-terminal nodes
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Hello, I am Sam Trenholme, the implementer and maintainer of MaraDNS.
This email discusses whether to return NXDOMAIN or NOERROR with
non-terminal nodes.

I apologize for not writing this email sooner.  I became aware of the
relevant discussion this morning.  A description is here:

http://samiam.org/blog/20110423.html

To summarize:  Let us suppose we have the DNS name
www.sub.example.com, but, for whatever reason, sub.example.com does
not exist.  Let us further suppose that someone sends a request for
sub.example.com.  Do we return a NXDOMAIN or a "NOERROR" reply?

MaraDNS 1.0 returned a NOERROR reply.  MaraDNS 1.2 and later return a
NXDOMAIN reply.

The reason for the 1.0 -> 1.2 change is because I once got a private
email from a developer of an embedded DNS server.  This server was
unable to process "NOERROR" replies and thought it got a positive
reply if it received a NOERROR answer.

Since MaraDNS uses a hash to store records, it would be non-trivial to
return "NOERROR" for non-terminal nodes.  Since Paul Vixie has said
that "NOERROR" should not be returned in this case, this was
reasonable behavior when I implemented it thusly nearly six years ago.

MaraDNS does not have support for edns0 nor for DNSSEC, so mandating
this behavior only for DNSSEC-aware DNS servers would be reasonable.
However, since MaraDNS is only being maintained and is no longer
actively developed, it would be unfair to create a new RFC that
retcons under what circumstances a NXDOMAIN reply is sent from DNS
servers without edns0/DNSSEC support.

Please update http://tools.ietf.org/html/draft-vixie-dnsext-resimprove-00
appropriately.

Thank you for your time,

- Sam

P.S. As an aside, while I do side with DJB here, I do not always agree
with him.  For example:
http://maradns.blogspot.com/2010/09/eulogy-for-dnscurve.html