Subject: TECH-ERROR: DNS Server Requirements

From: "Jim Lyon" <[email-masked]>
Date: Mon, 23 Aug 2004 17:10:17 -0700

The Protocol spec (draft-ietf-marid-protocol-03) has the following
interesting sentence in section 2.1.6:

    Nevertheles, Sender-ID compliant sites MUST use DNS recursive
    servers that support EDNS0 [RFC2671] and [RFC3226] in order to
    be able to receive large DNS RR sets.

Problems:

1. This sentence is unclear. Either it means "servers MUST support
RFC2671 and RFC3226, and the reason is to receive large DNS RR sets", or
it means "if servers want to receive large DNS RR sets, they must
support RFC2671 and RFC3226."  I'm assuming the first meaning was
intended.

2. The reference to RFC3226 is irrelevant.  RFC3226 says, in essence,
that DNS servers that support either DNSSEC or IPv6 MUST also support
EDNS0.

3. While EDNS0's job is to ameliorate the pain of large DNS responses,
the SenderID and the DNS system will work correctly without it.  In
fact, there will probably be very few sites whose published records
exceed a basic DNS packet.

4. While it's a good idea for DNS servers and resolvers to support
EDNS0, many of today's don't.  This mandate will therefore get in the
way of adoption.

5. As far as I know, this particular question was not brought up on the
mailing list before inclusion of the mandate in the spec.

I therefore request deletion of this mandate. (I'd delete the entire
paragraph.)

-- Jim Lyon