1) A 32-bit address assigned to hosts that use TCP/IP. An IP address belongs to one of five classes, A, B, C, D, or E. An IP address is written as 4 octets separated with periods, referred to as dotted decimal format. Each address consists of a network number, an optional subnetwork number, and a host number. The network and subnetwork numbers together are used for routing, while the host number is used to address an individual host within the network or subnetwork. A subnet mask is used to extract network and subnetwork information from the IP address. Also called an Internet address.

2) The command used to establish the logical network address of an interface. See also IP and subnet mask.