Subnetmask /32 to /21
| Subnet /n | Subnet IP | Count |
| /32 | 255.255.255.255 | 1 |
| /31 | 255.255.255.254 | 2 |
| /30 | 255.255.255.252 | 4 |
| /29 | 255.255.255.248 | 8 |
| /28 | 255.255.255.240 | 16 |
| /27 | 255.255.255.224 | 32 |
| /26 | 255.255.255.192 | 64 |
| /25 | 255.255.255.128 | 128 |
| /24 | 255.255.255.0 | 256 |
| /23 | 255.255.254.0 | 512 |
| /22 | 255.255.252.0 | 1024 |
| /21 | 255.255.248.0 | 2048 |
The subnet mask is used to define the range of the network. And It is used IPv4 address.
It is able to specify the network range by combining the IP Address and net mask.
Subnet mask is generally used in the following cases.
- When managing a large number of PCs and servers separately.
- When restricting data references between another departments of a company.
- When separating the environment, such as separating the development environment and the production environment.
- When separating branch office networks which is separated location.
