On Wed, 6 Jun 2007, Peter Dambier wrote:
> There are two problems.
>
> 1) Only an autoritative nameserver (tinydns, axfrdns) can refuse
> recursion but dnscache is never authoritative.
True for the servers you name. But the difference between a recursor and
authority server is only the enabling/implementation of recursion, and
the presence of authority zones. Some people do have authority servers
recurse for them. BIND, PowerDNS, etc can be configured to do this.
There are some good reasons _not_ to do this, but there are some reasons
_to_ do it, too. I do it, but I hesitate to recommend others do it.
The primary advantage of such a setup is that DNS for your key domains
won't fail when/if you fall off the internet, doesn't fail internally if
your Domain fee is unpaid, etc. By contrast, if you have all clients
talk to a strict recursor like dnscache, it will have to get a
referral(s) to resolve names even in your own domains on startup. By
pointing clients at the recursion/authority servers, you don't need to
get referrals from the roots, etc to get things going internally. I
have authority servers either recurse or forward the request to a
recursor (e.g. powerdns -> dnscache). I like to have DNS for internal
domains working early on restart. [although, one might also be able to
prime the recursor cache with the right records, but I've never tried
that]
So, I think it would be 'strange, but possible' to have a recursor give
out a referral on a per-domain basis, with recursion on the others. I'm
still wondering the "why", though. But I can't think of any (eg RFC)
reason for "can't", except the lack of actual implementations that "do".
> 2) No client / nameserver who can do his own recursive nameresolution
> will ever ask dnscache.
Yes. I didn't think of that. Good catch.
But I think we are missing something in the requirement for the original
problem. Some more information would be helpful.
--Dean
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