3Com Switch 7750 Configuration Guide Guide

14
IP ADDRESS CONFIGURATION
IP Address Overview
IP Address Classification
and Representation
An IP address is a 32-bit address allocated to a device connected to the Internet. It
consists of two fields: net-id and host-id. To facilitate IP address management, IP
addresses are divided into five classes, as shown in
Figure 33.
Figure 33 Five classes of IP addresses
Class A, Class B, and Class C IP addresses are unicast addresses. Class D IP
addresses are multicast addresses and Class E addresses are reserved for future
special use. The first three types are commonly used.
IP addresses are in the dotted decimal notation. Each IP address contains four
decimal integers, with each integer corresponding to one byte (for
example,10.110.50.101).
Some IP addresses are reserved for special use. The IP address ranges that can be
used by users are listed in
Table 65.
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
0
1 0
1 1 0
1 1 1 0
1 1 1 1 0
net-id
net-id
net-id
Multicast address
Reserved address
host-id
host-id
host-id
Class A
Class B
Class C
Class D
Class E
net-id: Network ID; host-id: Host ID
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
0
1 0
1 1 0
1 1 1 0
1 1 1 1 0
net-id
net-id
net-id
Multicast address
Reserved address
host-id
host-id
host-id
Class A
Class B
Class C
Class D
Class E
net-id: Network ID; host-id: Host ID