[Ietf-not43] extensibility

[Eric A. Hall]

on 7/25/2003 4:11 PM Edward Lewis wrote:

> Perhaps yes to the latter question.  It's fairly clear to go to the 
> source of the authority and ask "who did you give it to" and chase 
> the chain of custody than reverse the path.  One reason - you can't 
> rely on there being a reverse DNS for the space.

This is how FIRS works with ASNs and IP addresses. Find the LDAP server
for asn.arpa, in-addr.arpa, etc., and follow the in-band referrals down.
DNS isn't being used everywhere, just for bootstrapping the query.

But having said that, DNS is still being used as the delegation
*authority* for the query, since the DNS information has control.

Separately, if this is trustworthy and reliable for finding the ~default
servers, then there's no reason not to use the same approach for finding
other partitions (eg, private route servers, or whatever).

> Another reason is 
> with the way addresses can be reassigned and used, it's not easy to 
> reverse the path. 

The only time you'd WANT to ask a specific server for its view of a piece
of data is because you have an application that knows it can benefit from
that data. As such, that application (which may just be your own personal
habit rather than a piece of code) would have to be wired to know "go ask
this partition for information about the resource".

All of that is only going to work if the delegation entries exist and are
functional. If the delegation entries don't work, you can't ask that
server for anything anyway.

Working delegations are only needed if you plan to offer a service at the
partition that is linked to the domain name in question. The other 99% of
the delegations don't even have to exist, much less be functional. If
nobody ever asks them for anything, who cares.

Now then, once there is a broad base of data ~out there, then I expect
that there will be more user-to-user applications, and those WOULD require
working delegations to function. It may be that using something like a
route server would make more sense than using DNS, but I'd want to discuss
this in the context of specific applications. In the general case, a
delegation is a delegation is a delegation.

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