NIS+ and Servers

Each domain is supported by a set of servers. The principal server is called the master server, and the backup servers are called replicas. Both master and replica servers run NIS+ server software. The master server stores the original tables, and the backup servers store copies.

NIS+ accepts incremental updates to the replicas. Changes are first made on the master server. Then they are automatically propagated to the replica servers and are soon available to the entire namespace.