Ip Addressing Configuration; Ip Addressing Overview; Ip Address Classes - H3C S5120-SI Series Configuration Manual

IP addressing configuration

IP addressing overview

IP address classes

IP addressing uses a 32-bit address to identify each host on a network. An example is
00001000000000010000000100000001 in binary, which can also be written as 10.1.1.1 in the easier-
to-read dotted decimal notation (in which each address is four octets in length).
Each IP address breaks down into two parts:
•
Net ID: Identifies a network. The first several bits of a net ID are known as the class field or class
bits. to identify the class of the IP address.
•
Host ID: Identifies a host on a network.
IP addresses are divided into five classes, as shown in Figure 7. The shaded areas represent the address
class.
Figure 7 IP address classes
Table 1 describes the address ranges of these five classes.
Table 1 IP address classes and ranges
Class
A
B
C
Address range
0.0.0.0 to
127.255.255.255
128.0.0.0 to
191.255.255.255
192.0.0.0 to
223.255.255.255
Remarks
The IP address 0.0.0.0 is used by a host at bootstrap for
temporary communication. This address is never a valid
destination address.
Addresses starting with 127 are reserved for loopback test.
Packets destined to these addresses are processed locally as input
packets rather than sent to the link.
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