[Samba] Domain controller could not be contacted

[Mark Fox]

I recently upgrade a Samba server, that was happily acting as a PDC for a
school, from 3.2 to 3.4.7. This was done via an upgrade to Ubuntu (from 9.04
to 10.04LTS). Of course, the Ubuntu upgrade caused a bunch of issues, most
of which were managed without undue stress. The remaining issues are with
Samba's configuration.

This is a fairly simple Samba configuration using the TDB password backend,
no LDAP.

After the upgrade, domain logons do not work, nor can new machines be joined
to the domain. From a Windows XP machine, attempting to log on gives "The
system can not log you on now because the domain CK is not available."

Attempting to join the domain yields: "A domain controller for the domain CK
could not be contacted. Ensure that the domain name is typed correctly.
[...]"  In the details for this message, it states that "The following error
occurred when DNS was queried for the service location (SRV) resource record
used to locate a domain controller for domain CK: The error was: 'DNS name
does not exist.'" It also states that "The query was for the SRV record for
_ldap._tcp.dc._msdcs.CK" This seems strange because we aren't using LDAP.

Workgroup machines work. But they can't browse the domain. Going directly to
a share on the server via the FQDN works. This looks like a winbindd issue
to me. On the Linux side, connecting to a share on the server with smbclient
works fine. In all honesty, I don't have much knowledge of tools for
debugging NetBIOS issues with Samba. It's always just worked for me.

Any ideas what could be going on here? Suggestions for further inquiry?


Mark