H3C S7500E Series Ethernet Switches Operation Manual

Operation Manual – IP Addressing and Performance
H3C S7500E Series Ethernet Switches Chapter 1 IP Addressing Configuration
1-1
Chapter 1 IP Addressing Configuration
When assigning IP addresses to interfaces on your device, go to these sections for
information you are interested in:
z IP Addressing Overview
z Configuring IP Addresses
z Displaying and Maintaining IP Addressing
1.1 IP Addressing Overview
This section covers these topics:
z IP Address Classes
z Special Case IP Addresses
z Subnetting and Masking
1.1.1 IP Address Classes
IP addressing uses a 32-bit address to identify each host on a network. An example is
01010000100000001000000010000000 in binary. To make IP addresses in 32-bit form
easier to read, they are written in dotted decimal notation, each being four octets in
length, for example, 10.1.1.1 for the address just mentioned.
Each IP address breaks down into two parts:
z Net-id: First several bits of the IP address defining a network, also known as class
bits.
z Host-id: Identifies a host on a network.
For administration sake, IP addresses are divided into five classes. Which class an IP
address belongs to depends on the first one to four bits of the net-id, as shown in the
following figure (in which the blue parts represent the address class).
0 Net-id Host-id
1 Net-id Host-id0
1 Net-id Host-id01
1 Multicast address011
1 Reserved111
Class A
0 7 15 23 31
Class E
Class D
Class C
Class B
Figure 1-1 IP address classes