[Samba] AD DC out of sync

[Lars Hanke]

It now happened for the second time: Out of the blue, I could not login 
from windows machines or authenticate using smbclient, while 
Kerberos/nslcd were still working fine, after setting a password.

The cause is that the password change didn' reach both AD DCs, but only 
one. The other one still had the old value as could be seen by 
samba-tool ldapcmp. Restarting the DCs and waiting for a couple of 
seconds brings them back to sync and Windows logons work as they used to.

samba-tool drs showrepl does not show any failure, beyond: Warning: No 
NC replicated for Connection!

Any idea, what I should do next time to obtain valuable output for 
debugging?

Kind regards,
  - lars.