Unwanted ISDN connections caused by BIND

[Brian {Hamilton Kelly}]

On 9 Aug, in article
     <29841.934221349 at kludge.mpn.cp.philips.com>
     jim at mpn.cp.philips.com "Jim Reid" wrote:

> >>>>> "Bernd" == Bernd =?iso-8859-1?Q?P=F6rner?= <Bernd> writes:
> 
>     Bernd> Every time the machine boots it makes an unwanted ISDN connection to
>  the
>     Bernd> provider, exactly in the moment when BIND starts. Also later, in
>     Bernd> irregular intervals, the machine makes unwanted ISDN connection. I
> 
> This is to be expected. Your name server has to talk to other name
> servers, especially if it has to resolve external names. What you
> could do is configure your PPP/ISDN code to only let DNS traffic out
> if the serial line is already up. [OTOH, that might stop external
> lookups from working, zone transfers might fail, valid zones could
> expire, etc, etc.] Another approach would be to keep the line up for
> one PPT-charging-unit after the DNS lookup in the hope that someone
> generates some off-site traffic - web access or whatever - soon after
> they'd looked up the external name.

This is actually BIND trying to refresh its cache vis-a-vis the root
nameservers, SFAICT.  I have a similar setup (except with OS/2 Warp and
ISDNpm v2.9) and once BIND starts, it does a dial-on-demand trying to
contact each of the IP numbers for the 14 (? --- I haven't counted
lately) root nameservers.  (Well, strictly speaking, it just tries to
contact one of them, I guess; but if my D-o-D is inhibited, it tries to
contact each in turn --- and goes on and ON, until I re-enable the
D-o-D.)

Once BIND is running, it can go a week without my having made another
connection to the outside world.

I had a sort of feeling that when I first read the BIND v8.2.x
documentation, there was some sort of option that said "don't bother
refreshing the hints cache" but since having hit this problem, I can't
seem to find it (so may have imagined it).

Obviously with a D-o-D connection such as this, I'm serving up my
internal LAN, and use a forwarders line to specify my ISP's nameservers;
what would be nice would be if BIND didn't try to update its hints until
it knew there was an open connection (triggered off by a requirement to
use one of the forwarders).

-- 
Brian {Hamilton Kelly}                                         bhk at dsl.co.uk
    "But we're a university.  We /have/ to have a library!..."said Ridcully,
         "What sort of people would we be if we didn't go into the library?"
    "Students", said the Senior Wrangler, morosely. [TP: The Last Continent]