System Administration Guide: Naming and Directory Services (NIS+)

NIS+ Server Running at Security Level 0

A server running at security level 0 does not create or maintain credentials for NIS+ principals.

If you try to use passwd on a server that is running at security level 0, you will get the error message: You name do not have secure RPC credentials in NIS+ domain domainname.

Security level 0 is only to be used by administrators for initial namespace setup and testing purposes. Level 0 should not be used in any environment where ordinary users are active.