[Samba] Internal DNS not running

[simon+samba at matthews.eu]

After running the classicupgrade, configuring and starting krb5, starting 
the new samba4 server, I started looking at DNS.

Nothing is listening on port 53, so I assume the internal DNS is not 
working. I have NOT specified the use of the BIND_DLZ plugin, so it should 
be using its internal dns server.

Where should I start looking for a solution to this?