NETGEAR RT338 Reference Manual page 30

Reference Guide for the Model RT338 ISDN Router
There are five standard classes of IP addresses. The address classes determine the network and host
sections of the address differently. Address classes allow for different numbers of hosts on a
network. Each address type begins with a unique bit pattern, which is used by the TCP/IP software
to identify the address class. After the address class has been determined, the software can
correctly identify the host section of the address. The three main address classes are illustrated in
Figure 1-1, which shows the network and node sections of the address for each address type.
Class A
Network
Class B
Network
Class C
Network
1-8
Node
Node
Node
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Introduction