caching only NS grabs only RR's or complete Zones ?

[Pete Ehlke]

* Markus Weber <linux at leute.server.de> said, on [020117 08:25]:
> 
> I've got a little question.
> My caching only nameserver could not resolve a name that was newly
> introduced in the zonefile of the authoritative NS.
> but then, when i made the caching only nameserver as a slave for the
> zone and transferred it too, it could resolve the name.
> so, could it be that when a caching only nameserver try to lookup a single
> name, like "bindlist.isc.org" he catches the complete zonefile with all
> records ??
> if not, i dont understand why the nameserver couldn't resolve the new
> introduced host (CNAME).

The most likely scenario is that your caching server performs negative
caching, and had an NXDOMAIN response for the RR in its cache. In other
words:

Someone asked your caching server for nosuchserver.somedomain.com, your
server got an NXDOMAIN response with, say, a 1 hour TTL. Ten minutes
later, a record for nosuchserver was added to the somedomain.com zone.
Your caching server will hold on to the NXDOMAIN answer until its TTL
expires, and *then* go back to the somedomain.com servers to ask again,
getting the new record.

-Pete