An identifier for a computer or device on a TCP/IP
network. Networks using the TCP/IP protocol route messages based on the
IP
address of the destination. The format of an IP address is a 32-bit numeric address written as four numbers separated by periods. Each number can be zero to 255. For example, 1.160.10.240 could be an IP address.
Within an isolated network, you can assign an IP address at random as long as each one is unique. However, connecting a private network to the Internet requires using a registered IP address (called Internet
addresses) to avoid duplicates.
The four numbers in an IP address are used in different ways to identify a particular network and a host on that network. Four regional Internet registries -- ARIN, RIPE NCC, LACINIC and APNIC -- assign Internet addresses from the following three classes.