By ToolzHive · Updated
IPv4 addresses have 32 bits; the prefix identifies the network bits. Find the containing network before assigning hosts.
Reference table
| Step | Operation | 192.168.10.77/26 |
|---|---|---|
| 1 | Find subnet mask | 255.255.255.192 |
| 2 | Find block size | 256 − 192 = 64 |
| 3 | Locate containing block | 64 through 127 |
| 4 | Network address | 192.168.10.64 |
| 5 | Broadcast address | 192.168.10.127 |
| 6 | Conventional host range | 192.168.10.65 – 192.168.10.126 |
| 7 | Total / conventional hosts | 64 / 62 |
Host-count exceptions
2^(32−prefix)−2 applies to ordinary broadcast subnets. Both /31 addresses can be used on point-to-point links under RFC 3021. A /32 denotes one address, often a host route.
Splitting example
192.168.10.0/24 divides into .0/26, .64/26, .128/26 and .192/26. Check that the chosen networks do not overlap existing routes.
Try the related tools
- IPv4 Subnet Calculator — Calculate network, broadcast, host range and mask for any IPv4 subnet, and split it.