Subnet And Mask; Configure Ip Address - Huawei Quidway S3500 Series Operation Manual

Operation Manual - Network Protocol
Quidway S3500 Series Ethernet Switches

1.1.2 Subnet and Mask

Nowadays, with rapid development of the Internet, IP addresses are depleting very fast.
The traditional IP address allocation method wastes IP addresses greatly. In order to
make full use of the available IP addresses, the concept of mask and subnet is
proposed.
A mask is a 32-bit number corresponding to an IP address. The number consists of 1s
and 0s. Principally, these 1s and 0s can be combined randomly. However, the first
consecutive bits are set to 1s when designing the mask. The mask divides the IP
address into two parts: subnet address and host address. The bits 1s in the address
and the mask indicate the subnet address and the other bits indicate the host address.
If there is no sub-net division, then its sub-net mask is the default value and the length
of "1" indicates the net-id length. Therefore, for IP addresses of classes A, B and C, the
default values of corresponding sub-net mask are 255.0.0.0, 255.255.0.0 and
255.255.255.0 respectively.
The mask can be used to divide a Class A network containing more than 16,000,000
hosts or a Class B network containing more than 60,000 hosts into multiple small
networks. Each small network is called a subnet. For example, for the Class B network
address 138.38.0.0, the mask 255.255.224.0 can be used to divide the network into 8
subnets:
138.38.160.0, 138.38.192.0 and 138.38.224.0 (Refer to the following figure). Each
subnet can contain more than 8000 hosts.
ClassB ClassB
138.38.0.0 138.38.0.0
Standard Standard
mask mask
255.255.0.0 255.255.0.0
Subnet mask Subnet mask
255.255.224.0 255.255.224.0
Subnet address: Subnet address: Subnet address: Subnet address:
000 000
001 001
010 010
011 011
100 100
101 101
110 110
111 111
Figure 1-2 Subnet division of IP address

1.2 Configure IP Address

Configure an IP address for VLAN interface in one of three ways:
138.38.0.0, 138.38.32.0,
10001010, 00100110, 000 00000, 00000000 10001010, 00100110, 000 00000, 00000000
11111111, 11111111, 000 00000, 00000000 11111111, 11111111, 000 00000, 00000000
11111111, 11111111, 111 00000, 00000000 11111111, 11111111, 111 00000, 00000000
Subnet address: 138.38. Subnet address: 138.38. 0. 0.
Subnet address: 138.38. 32. Subnet address: 138.38. 32.
Subnet address: 138.38. 64. Subnet address: 138.38. 64.
Subnet address: 138.38. 96. Subnet address: 138.38. 96.
Subnet address: 138.38.128. Subnet address: 138.38.128.
Subnet address: 138.38.160. Subnet address: 138.38.160.
Subnet address: 138.38.192. Subnet address: 138.38.192.
Subnet address: 138.38.224. Subnet address: 138.38.224.
Huawei Technologies Proprietary
Chapter 1 IP Address Configuration
138.38.64.0,
Subnet Subnet
Host Host
number number
number number
0 0
0 0
0 0
0 0
0 0
0 0
0 0
0 0
1-3
138.38.96.0, 138.38.128.0,