When Samba is configured to use an LDAP or other identity management and/or
directory service, it is Samba that continues to perform user and machine
authentication. It should be noted that the LDAP server does not perform
authentication handling in place of what Samba is designed to do.
Please refer to
Domain Control, for more information regarding
how to create a domain machine account for a domain member server as well as for
information on how to enable the Samba domain member machine to join the domain
and be fully trusted by it.