Specify the TCP/IP interface network mask of the HMC.
The TCP/IP network mask, combined with the TCP/IP address, identifies the subnetwork in which the HMC is located.
The TCP/IP address is made of up a network address that uniquely identifies the network, followed by a local address that uniquely identifies the HMC to the network. The local address can also be used to identify a logical network, or subnetwork, of the actual network.
The TCP/IP address and network mask combine to distinguish the subnetwork address from the local address.