Re: DNS vs. non-DNS Data (was Re: Signature at parent (draft-ietf-dnsop-parent-sig-00.txt))

["Eric A. Hall" <[e-mail]>]

>   | Is it a lookup and not data.
> 
> I have no idea what that means.   If it is in the DNS, it is going to
> be used in a lookup, or having it would certainly be a wast of time.
> If it is going to be represented in the DNS, it is certainly going
> to be data.   Hence, I would have thought everything in the DNS is
> used in a lookup and is data...

I consider "lookup" to be a piece of required data which is necessary for
a distributed (eg, Internet-wide) application process to complete.

I consider "data" to be (poorly termed) information which is not required
for the distributed portion of the application process to complete.

MX is a lookup for a remote domain's mail servers and is necessary for
SMTP delivery over the Internet to complete. MB is data which is not
required for the Internet portion of the process. Local mailertable RRs
would also not meet this requirement, but reusing MX for this is not
necessarily bad.

> Certainly the vast majority of the A records are only used locally,
> are you suggesting that they shouldn't be in the DNS but should be
> someplace else instead?

As a class of data, A RRs are necessary for distributed network processes
to complete. Something that provided MAC addresses would be local-only. RT
RRs are probably local-only.

> It could be considered to be that way, but without any rational
> justification.   If MX is on the "wrong side", then I don't think
> there's any data in the DNS that would justify staying, certainly I
> don't see A or PTR as being any different than MX.

[I may be wrong on MX, I'm trying to define the line too.]

My feeling is that MX is wrong when it is compared to SRV because SRV uses
protocol-specific labels which are not likely to cause overload. If SRV
were used with DNs without the service-specific labels (similar to the MX
method) then we could end up with dozens of service-specific RRs
associated with a DN, such that requests for qtype=* qname=oz.au. would be
overloaded.

> I guess you'd just be left with the RRs that build the tree (NS and
> SOA), without which there would be no DNS at all.

Well, that's certainly not my goal. :p

-- 
Eric A. Hall                                        http://www.ehsco.com/
Internet Core Protocols          http://www.oreilly.com/catalog/coreprot/


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