Problem: _VLMCS Entries as Rejects

Problem:

The S4-Connector reports rejects about DNS entries of _VLMCS objects.

Environment

UCS4 with Windows 10 as domain clients.
In /var/log/univention/connector-s4.log entries can be found as follows:

24.11.2019 06:26:01.196 LDAP        (PROCESS): sync to ucs: Resync rejected dn: DC=_VLMCS._TCP,DC=multi.ucs,CN=MicrosoftDNS,CN=System,DC=multi,DC=ucs
24.11.2019 06:26:01.273 LDAP        (PROCESS): sync to ucs:   [           dns] [       add] relativeDomainName=_VLMCS._TCP,zoneName=multi.ucs,cn=dns,dc=multi,dc=ucs
24.11.2019 06:26:01.290 LDAP        (ERROR  ): Unknown Exception during sync_to_ucs
24.11.2019 06:26:01.291 LDAP        (ERROR  ): Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/univention/s4connector/__init__.py", line 1540, in sync_to_ucs
    result = self.property[property_type].ucs_sync_function(self, property_type, object)
  File "/usr/lib/python2.7/dist-packages/univention/s4connector/s4/dns.py", line 1727, in con2ucs
    ucs_srv_record_create(s4connector, object)
  File "/usr/lib/python2.7/dist-packages/univention/s4connector/s4/dns.py", line 1207, in ucs_srv_record_create
    newRecord.create()
  File "/usr/lib/pymodules/python2.7/univention/admin/handlers/__init__.py", line 550, in create
    dn = self._create(response=response, serverctrls=serverctrls)
  File "/usr/lib/pymodules/python2.7/univention/admin/handlers/__init__.py", line 1268, in _create
    self.lo.add(self.dn, al, serverctrls=serverctrls, response=response)
  File "/usr/lib/pymodules/python2.7/univention/admin/uldap.py", line 855, in add
    raise univention.admin.uexceptions.objectExists(dn)
objectExists: relativeDomainName=_VLMCS._None,zoneName=multi.ucs,cn=dns,dc=multi,dc=ucs

Solution

This seems to be a behaviour of specific Windows10 versions depending on the type of license key they use.
To stop Windows from creating these _vlmcs use on Windows:
slmgr.vbs /cdns
Reference (German only)