HP-UX LAN Administrator's Guide (Feburary 2007)

DRAFT COPY Network Addressing
Internet Addresses
Chapter 7 101
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 7-1. 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.”
Figure 7-1 Internet Address Classes
The address classes can also be broken down by address ranges. Internet addresses are
typically represented by converting the bits to decimal values an octet (8 bits) at a time, and
separating each octet's decimal value by a period ( . ). Therefore, internet addresses are
typically of the following form:
n.n.n.n
31 23 0
31 30 0
31 29 07
15
0
10
110
Class A
Network Address Host Address
Class B
Class C
Network Address Host Address
Network Address Host Address