Unwanted ISDN connections caused by BIND

[Bernd Pörner]

We have a linux box acting as DNS, mail and proxy server. We are
connected to our provider via an ISDN line. Our BIND version is
8.1.2-22.

Every time the machine boots it makes an unwanted ISDN connection to the
provider, exactly in the moment when BIND starts. Also later, in
irregular intervals, the machine makes unwanted ISDN connection. I ran
"isdnctrl verbose 3" to find out which process makes these connections.
They are made via UDP protocol over port 53 (which is BIND's port).

Another curious thing:
If BIND is started during boot-up, sendmail is unable to start during
boot-up. After boot process is over I can start sendmail
("/sbin/init.d/sendmail start") without problems.
If BIND isn't started during boot-up, sendmail can be started without
problems during boot-up.

Any ideas?

Bernd