This program is used to set up the networking configuration for a particular networking interface card (ethernet, tokenring or arcnet) that's being configured for running TCP-IP. You can either manually configure a device, tell the system to use dhcp or bootp to request networking configuration from a server on the local network, or not configure TCP-IP networking on that interface at all.
If you run this program from the administration tool, the first thing it will do is bring up a menu of the ethernet devices that are configured into your system. To edit one, merely choose it from the menu and hit return. If, on the other hand, you wish to set the network configuration of a device that does not exist, you will need to run the /usr/lib/admin/network program from a command line, passing in the name of the device.
From the network selection screen, you can choose how to configure the networking. If you choose dhcp or bootp, you also have the option of choosing to have the system attempt to configure your DNS and NIS from the configuration that dhcp or bootp returns. If you choose to configure this device by hand, you will be asked to set the IP address and the network of the interface, plus, optionally, the netmask and default gateway for it. Note that unless you are running routing software on this machime, you'll need to have a default gateway if you wish to get to any place aside from the local network.
If you are manually configuring an interface, the program will attempt to be helpful. When you enter the IP address for an interface, the program will attempt to deduce the network and netmask for you, and if you enter the IP address in CIDR form (address/network width), it will fill in the network and netmask, and then not allow you to change them at all.