By default, if no server preferences have been set with the nisprefadm command, a client will first try to obtain the information it needs from an NIS+ server on the client's local subnet. If the client finds an active server on the local subnet, it obtains the information it needs from the first local server that responds. If no server is available on the local subnet, the client searches outside the local subnet, and obtains the NIS+ information it needs from the first remote server that responds.
When multiple servers on a subnet are serving a large number of clients, the random nature of the client's default search pattern may result in some servers being over worked while others are under used.
When a client has to seek an NIS+ server beyond the local subnet, it will obtain its information from the first server that responds even if that server is overworked, or linked to the client's subnet by a slower Wide Area Network connection such as a modem or a dedicated line that is already carrying heavy traffic.