Re: [Add] Zone ownership in DNS server discovery

[Joe Abley <[e-mail]>]

Hi Tommy,

On Sep 10, 2020, at 18:32, Tommy Jensen <Jensen.Thomas=[e-mail]> wrote:

> Changing subject line to avoid the noise on Martin's single use case. This is a separate topic.
> 
> >From the WG charter:
> 
> > Define a mechanism that allows communication of DNS resolver
> > information to clients for use in selection decisions. This could be
> > part of the mechanism used for discovery, above
> 
> If I know "doh.example.com" is authoritative for "foo.example.com", I may prefer to take *.foo.example.com queries directly to it instead of using an intermediary recursive.

In the taxonomy described in RFC 8499, "clients" in the ADD charter refers to "stub resolver" -- "a resolver that cannot perform all resolution itself". The phrase "resolver information" in the charter refers to information about "recursive resolvers" -- resolvers that operate in "recursive mode".

What you are describing above is a hybrid entity that behaves like a stub resolver in some cases but like a recursive resolver in others. The opportunistic choice of transport between this new entity and a particular authoritative server is by definition not communication between stub resolver and recursive resolver (as defined in RFC 8499) or between client and resolver (as described in the ADD charter).

This might be an interesting discussion to start in DNSOP, perhaps as part of a larger discussion about capabilities negotiation between authoritative servers and their clients, but I think it's out of scope for ADD.


Joe