Windows XP name lookup when joining a domain

[Tom Alsberg]

Hi there.
[Sorry if you got this message already and are seeing it again. I did
not get a copy of it, and no replies to it (and I would really like
some help with this)]

I am recently working on debugging some changes we made to Samba at
our site. Pretty much everything is working now - printing (with and
without MS-RPC [SPOOLSS]), directory shares, user mapping...
I am now into getting it to work as a domain controller for Windows NT
4.0, Windows 2000, and Windows XP clients.

A few days ago, something weird happened. While testing some things
with some Windows XP clients, some-when all clients stopped finding
and being able to contact the domain controller for the domain.
Nothing seems to have changed at that time, except the log level of
smbd and nmbd (from 4 to 10). I tried changing it back just to be
sure, but that's not the cause.

Joining the domain didn't work for other reasons previously I was
working on fixing... But now somehow the Windows clients have another
problem, which I have not been able to figure out by now.

When trying to join the domain DEVIL, whose domain controller is DEV,
running Samba 3.0-alpha, by the Windows XP Professional client GX-100,
Windows XP gives a message that the domain controller could not be
contacted.
In addition, it gives the following diagnostics message:

<snip>
  The domain name devil might be a NetBIOS domain name.  If this is the
  case, verify that the domain name is properly registered with WINS. 

  If you are certain that the name is not a NetBIOS domain name, then
  the following information can help you troubleshoot your DNS
  configuration. 

  The following error occurred when DNS was queried for the service
  location (SRV) resource record used to locate a domain controller for
  domain devil: 

  The error was: "DNS name does not exist."
  (error code 0x0000232B RCODE_NAME_ERROR)

  The query was for the SRV record for _ldap._tcp.dc._msdcs.devil

  Common causes of this error include the following:

  - The DNS SRV record is not registered in DNS.

  - One or more of the following zones do not include delegation to its
  child zone:

  devil
  . (the root zone)

  For information about correcting this problem, click Help.
</snip>

According to this diagnostics message, it seems like Windows XP is
trying to locate the domain DEVIL in DNS... But that shouldn't be so,
it is a domain in NetBIOS/WINS (nmbd knows about it)... I also tried
setting in the WINS configuration for the connection that machine
(dev) as the WINS server, but that does not seem to help.
The domain is in WINS, and visible in NetBIOS, according to
nmblookup. Also browsing the workgroup usually works, and browsing
shares, etc. in the server works fine.

Also, it doesn't really look for it in DNS. I tried taking network
(packet) dumps (with Microsoft NetMon and tcpdump), as well as logging
all DNS queries on the name servers, and that does not seem to be so.

According to the network dumps, the Windows XP client does try to look
up the domain DEVIL, with three identical NetBIOS Name Service (NBNS)
requests to the server DEV (probably because I set it as the WINS
server), and three identical requests to the broadcast address. It
doesn't seem to get any reply.
The client does not contact smbd during that.

Any idea what the problem might be? What could have changed? How I can
check it further? What could the reason nmbd suddenly sends no replies
be?

I can provide network (packet) dumps and server logs, if those will be
of use (but I don't see any additional relevant information there).

  Thanks, any help appreciated,
  -- Tom

-- 
  Tom Alsberg
	Hebrew University of Jerusalem, Israel,
	Institute of Computer Science and Engineering -
		System Group / Computer Vision Lab