NIS+ provides preset security defaults for the root domain. The default security level is level 2. Operational networks with actual users should always be run at security level 2. Security levels 0 and 1 are for configuring and testing purposes only. Do not run an operational network at level 0 or 1.
The NIS+ security system is complex. If you are not familiar with NIS+ security, you might want to review Chapter 11, NIS+ Security Overview before starting to configure your NIS+ environment.