/25 Subnet Mask Reference (255.255.255.128)
Half of a /24 block—ideal for splitting a standard office LAN into two isolated VLANs.
| CIDR Prefix | /25 |
|---|---|
| Subnet Mask | 255.255.255.128 |
| Wildcard Mask (Cisco / ACL) | 0.0.0.127 |
| Total IPv4 Addresses | 128 |
| Usable Host IPs | 126 |
| Binary Subnet Mask | 11111111.11111111.11111111.10000000 |
| Example Block (10.0.0.0/25) | 10.0.0.0 – 10.0.0.127 |
| Example Usable Hosts | 10.0.0.1 – 10.0.0.126 |
Need to compute custom IP ranges? Try the Interactive Subnet Calculator or VLSM Splitter.