Another way to find the primary server for a zone

[Kevin Darcy]

Brad Knowles wrote:

> At 4:48 PM +0100 5/10/01, Jim Reid wrote:
>
> >                                         However if you plan to use
> >  Dynamic DNS (DDNS), you *must* provide the name of the master server
> >  in the MNAME. This is the only way for DDNS clients to find out where
> >  to send their dynamic update requests. These obviously can only be
> >  processed on the zone's master server.
>
>         Interesting.  I was not aware of this use of the MNAME field.  I
> guess this kind of rules out stealth primaries, eh?

Nope. The BIND 9 nsupdate utility allows you explicitly specify the
destination for the update, thus overriding the MNAME. I'm sure other Dynamic
Update APIs have similar override mechanisms.

I've just recently integrated a "hidden master" setup for our external
DNS zones with our Dynamic Update-based DNS maintenance system. This feature
of BIND 9's nsupdate was the missing piece to make all of that work (well,
that and hacking the resolver library to allow an environment variable to
override the nameservers in /etc/resolv.conf)...


- Kevin