The interface parameter is the name of the network interface. On EISA-based machines, that name is of the form nsn for Ethernet interfaces and fin for FDDI interfaces, where n is that interface's ordinal number (e.g., the first Ethernet interface is ns0, the second is ns1, etc.). On PCI-based machines, that name is of the form en for Ethernet interfaces, fn for FDDI interfaces, and an for ATM interfaces, possibly followed by a letter, where n is 0 for on-board interfaces and the expansion slot number for interfaces plugged into expansion slots. If a card in an expansion slot has more than one interface, the interface name will be followed by a letter between a and z indicating which of the interfaces on that card it is. The interface name -a is special and it does not take any optional paremeters. It displays the current configuration for all the network interfaces present.
The address is either a host name present in the host name data base /etc/hosts or an Internet address expressed in the Internet standard dot notation.
On a 10/100 Mbps interface, the system will auto-detect a 10 Mbps or 100 Mbps link and set the link speed accordingly when the interface is configured up. The hardware is not currently capable of auto-detecting full duplex interfaces, so if full duplex operation is desired, it must be explicitly set using the mediatype command. Only the 10/100 Mbps interfaces are capable of full duplex operation.
mtusize size Specify the MTU (maximum transmission unit) to use for the interface. This is normally necessary only for non-compliant FDDI to Ethernet bridges, routers or switches that don't know how to fragment FDDI size packets to Ethernet sized packets.
netmask mask The mask includes the network part of the local address and the subnet part, which is taken from the host field of the address. The mask can be specified as a single hexadecimal number with a leading 0x, with a dotnotation Internet address, or with a pseudonetwork name listed in the network table /etc/networks. The mask contains 1's for the bit positions in the 32-bit address that are to be used for the network and subnet parts, and 0's for the host part. The mask should contain at least the standard network portion, and the subnet field should be contiguous with the network portion. A default net_mask is chosen according to the class of the IP address.