Installing and Administering LAN/9000 Software

Chapter 6 133
Network Addressing
Internet Addresses
Internet Addresses
Internet addresses are used extensively by LAN and WAN products as
well as Internet Services.
An internet address (often referred to as the IP address) consists of two
parts:
• Network address.
• Host address.
The network address identifies the network. The host address identifies
a node within the network. A network address is concatenated with a
host address to form the internet address and to uniquely identify a node
within a network.
Internet Address Formats
There are four internet address classes, each accommodating a different
number of network and host addresses. The address classes are defined
by the most significant bits of the binary form of the address as shown in
Figure 6-1. This section discusses three of the classes (Class A, Class B,
Class C). The fourth class (Class D) is discussed in the section “IP
Multicast Addresses.”