Comment 9 for bug 1572122

I should mention that all the servers effected where using the LDAP backend setup via smbldap-tools. Some server were running winbind but not all. Machines were mix of 32-bit and 64-bit installs.

Clients with login problems were both Windows 7 and XP joined to a domain. Sometimes a user could login to a machine using a recently used user account (info probably cached on locally on Windows machine). File access to server was fine. Leaving and rejoining the domain produced no error, but users could still not login.

Example of Samba log file from when the login failed:
[2016/04/19 10:00:37.960814, 0] rpc_server/netlogon/srv_netlog_nt.c:976(_netr_S
erverAuthenticate3)
  _netr_ServerAuthenticate3: netlogon_creds_server_check failed. Rejecting auth
request from client WIN7-DATABASE machine account WIN7-DATABASE$
[2016/04/19 10:00:37.978252, 1] rpc_server/srv_pipe.c:1845(api_pipe_request)
  srv_pipe_check_verification_trailer: failed
[2016/04/19 10:00:50.068608, 1] smbd/process.c:457(receive_smb_talloc)
[2016/04/19 10:01:39.597632, 0] rpc_server/netlogon/srv_netlog_nt.c:976(_netr_S
erverAuthenticate3)
  _netr_ServerAuthenticate3: netlogon_creds_server_check failed. Rejecting auth
request from client WIN7-DATABASE machine account WIN7-DATABASE$
[2016/04/19 10:01:39.620571, 1] rpc_server/srv_pipe.c:1845(api_pipe_request)
  srv_pipe_check_verification_trailer: failed
[2016/04/19 10:01:55.838151, 1] smbd/process.c:457(receive_smb_talloc)