To divide a subnet is to divide a network into several identical networks. This network has its own broadcast domain and initial IP address.
The subnet mask will not reduce the number of hosts in this network
For example, 10.0.0.0/24 has 256-2=254 available physical hosts in the network 10.0.0.1————10.0.0.254
10.0.0.7/25 10.0.0.1—————10.0.0.126
10.0.0.177/25 10.0.0.129—————10.0.0.254
If the subnet mask becomes 25, it will be divided into 2 subnets. This is to divide the 254 hosts on the 10.0.0.0/24 network into 2 subnets.
If the subnet mask becomes 26, 4 subnets will be divided
27———————————— 8 subnets
28———————————— 16 subnets
29———————————— 32 subnets
30———————————— 64 subnets
A major premise is that there must be a certain network: 10.0.0.0/24
This network can be 10.0.0.0/8—————— That is, there are a total of 1677216 physical hosts in this network
Then assign him a subnet:
It can be seen that when the subnet mask of 10.0.0./8 becomes 24, the number of subnets is 256, and the number of hosts in each subnet is 65536.
Must understand
- Have a certain network
- The subnet mask is only determined, how many subnets are there,,, how many hosts are in the subnet
- It’s not about IP. The last number of IP determines which subnet the host is in.
- There are many questions that will set up traps, often which subnet broadcast address will ask you if this IP is correct