The domain must have already been set up and its master server must be running.
The dbm files (.pag and .dir files) for the NIS maps you are going to load into the NIS+ tables must already be in a subdirectory of /var/yp.
Machine and user names cannot be duplicated. All users and all machines must have unique names. You cannot have a machine with the same name as a user.
Machine names cannot contain dots (periods). For example, a machine named sales.alpha is not allowed. A machine named sales-alpha is allowed.