[Samba] Domain demote fails

[Jochen Wezel - CompuMaster GmbH]

Hi together,

Trying to demote from our existing Windows-based Active directory domain results in following problem.
The ex-windc machine was a DC a few years ago - but currently it isn't any more. But the DC sever lookup mechanism identifies it incorrectly as an active DC :-(

root at srvf01:~# samba-tool domain demote -UAdministrator
Using ex-windc as partner server for the demotion
ERROR(<class 'samba.drs_utils.drsException'>): uncaught exception - drsException: DRS connection to SRV14.lan.compumaster.de failed: (-1073741249, 'NT_STATUS_PORT_UNREACHABLE')
  File "/usr/local/samba/lib/python2.7/site-packages/samba/netcmd/__init__.py", line 175, in _run
    return self.run(*args, **kwargs)
  File "/usr/local/samba/lib/python2.7/site-packages/samba/netcmd/domain.py", line 628, in run
    (drsuapiBind, drsuapi_handle, supportedExtensions) = drsuapi_connect(server, lp, creds)
  File "/usr/local/samba/lib/python2.7/site-packages/samba/drs_utils.py", line 54, in drsuapi_connect
    raise drsException("DRS connection to %s failed: %s" % (server, e))

Best Regards
Jochen