On Tue, Jul 18, 2006 at 07:06:46AM -0700, Bill Fenner wrote:
{this has been aging in my draft folder for too long}
> "any name registered anywhere in any IANA registry" to "the name
> from the port-numbers registry". The latter is particularly
> odd (you need to have a statically assigned port number in order
> to get a name to be able to use the record that allows you to use
> a dynamic port number), but seems fairly prevalent.
the latter seems pretty straightforward to me since 'services' as in 'ports'
are the next level in hierarchy when '_udp' and '_tcp' represent the
(transport) protocol, what they obviously do. Also, there's an explicit
reference to /etc/services under "The Port number".
But I'd also agree that the fixed port requirement might seem strange.
> a) I don't think there's a need to have globally unique
> values for the "service" of a SRV record - it's OK if there's
> an _spf._udp.example.com even if _spf is reserved as the "top
> level" reserved label.
This is a different issue.
> b) It's too high a barrier to require people who have validly
> been using values such as _http._tcp.example.com under the
> RFC 2782 rules to write an RFC in order to register the usage.
The validity of such use should be contested based on the "Applicability
Statement" in RFC 2782. But this again is a different issue.
Now, I regret having put this on the meeting agenda in a way less specific than
obviously necessary, so let's try to focus a bit and see what this group
can do about the "underscored" names:
1) There's the architectural issue of using a prefix at all, as described
in draft-iab-dns-choices-03.txt. The limitations are described there
as well, but there's a proposal in draft-hallambaker-pcon-00.txt
(the beef is in 3.4 and ignore the RR types used) that is definitely
worth an evaluation regarding coexistence of wildcards and the
prefix scheme.
2) There's the architectural (or protocol hygiene) issue of the '_' being
special or not and of "registering" names in an already delegated
namespace. This also has operational and layer9 aspects.
3) SRV is up for advancement to Draft in dnsext tentatively in January.
Some of the issues identified above, including the stale reference to
RFC 1700, would probably best be addressed during that review process.
What I'm missing a bit is a clear problem statement as to what problem
"underscore names" can solve that a dedicated RR type doesn't. Either may
have their merits, or even a combination of both, but we'd need that problem
description first. From what I've read I'd also doubt this is mostly about
wildcards.
Instead, "easy" extension of the query structure seems to be one goal.
-Peter, sans chapeau
.
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