IP Addressing

An IP address is a numeric identifier assigned to each machine on an IP network.

It designates the specific location of a device on the network.

IP addressing was designed to allow hosts on one network to communicate with a host on a different network regardless of the type of LANs the hosts are participating in.


IP Terminology

BIT: A bit is one digit, either a 1 or a 0.

BYTE: A byte is 7 or 8 bits, depending on whether parity is used. For the rest of this chapter, always assume a byte is 8 bits.

OCTET: An octet, made up of 8 bits, is just an ordinary 8-bit binary number. In this chapter, the terms byte and octet are completely interchangeable.

Network address: This is the designation used in routing to send packets to a remote network—for example, 10.0.0.0, 172.16.0.0, and 192.168.10.0.

Broadcast address: The address used by applications and hosts to send information to all nodes on a network is called the broadcast address.


Network Addressing


Subdividing an IP address into a network and node address is determined by the class designation of one’s network. This figure summarizes the three classes of networks.


Reserved Addressing


Private Addressing