Accessible by the system administrator. If something goes wrong, or if updates need to be made, it should be easy to reach the master server. The master server is usually a system that stays active for long periods of time. It needs to be stable so that the systems that depend on this master server enjoy uninterrupted service. Accessible from the network.
Some networks become complex with the presence of many gateways or bridges.
The master server should be accessible from most systems on the network. For a small number of hosts, each host can access the master server directly. However, for a larger number of hosts in a domain, the master server can become overloaded. So, to balance the NIS processing load and provide services when the master server is unavailable, additional hosts can be designated as slave servers. Slave Servers NIS slave servers act as intermediaries between clients and the master server by keeping exact replicas of the master server's maps.