Hi Matt:

On 05/19/11 17:08, Matthew Pounsett wrote:

While it's possible you have encountered a bug with BIND, it's
generally a bad idea to mix recursive and authoritative service in
the same process. The RFCs that define the resolution algorithms were
never written with mixed service in mind, and there are conflicts
that can result in undefined, and therefore unpredictable,
behaviours.   It will be hard to determine which you're seeing
without more specific information about the configuration of the
servers in question (e.g. which zones they're actually authoritative
for).

If you're saying that you shouldn't *offer* recursive and authoritative services on the same box, then I generally agree. If you're saying that you shouldn't ever prime your cache with a zone, or have a recursive server be a slave to anything, then I'd say it gets kind of hairy there.

A number of us have been doing that sort of thing for years, and there isn't really a way of getting certain zones to update quickly in a recursive server without really short TTLs, unless you do zone transfers. I bet Carlos's users demand this capability just as my users did when I worked on a university campus.

Moreover, the recommended RPZ configuration as of BIND 9.8.0 is to have your recursive servers slave your RPZ zone, so your recursives will have to slave something if they run RPZ.

You will particularly run into problems if you ever intend to do
DNSSEC validation on these name servers.. it just won't work.

Yes. In that case, static-stub or forwarding is your friend. Although, we should be clear: It won't work on the zones that are slaved by the recursive server. Presumably one is protecting those zones some other way (TSIG, SIG(0)). It *will* (and does) work for signed zones for which the recursor is not authoritative.

I maintained the cross-posting for this reply because of the general
DNS service advice, but my suggestion would be to limit the thread to
the bind-users until you identify or rule-out a bug.

Duly trimmed.

michael
_______________________________________________
bind-users mailing list
bind-users@lists.isc.org
https://lists.isc.org/mailman/listinfo/bind-users

Reply via email to