I will be pleasure if anyone can explain me difference between Windows (PDC) and Windows (ADS) authentication methods. (all that can be founded in documentation i am already know)

And i have one problem, every 5min i have this error:

"Jun 12 10:35:01 nas nis_mappings: UIDand GID database synchronization failed. Synchronization is disabled."

Option "Synchronize uid and gid database with NIS server" are disabled in my configuration, i am already try to reenable and disable it again.