Network Administrator how-to
How to Subnet a /24 Network into Four Subnets
Subnetting splits a network into smaller segments for security and organization.
Quick answer
Subnetting splits a network into smaller segments for security and organization. In short: start; to; each, then complete the remaining steps below.
Step by step
Start with the network 192.168.10.0/24 (256 addresses).
To make four subnets, borrow 2 bits: /24 becomes /26.
Each /26 has 64 addresses (62 usable hosts).
List the subnets: 192.168.10.0/26, .64/26, .128/26 and .192/26.
For each, the first address is the network and the last is the broadcast.
Assign usable ranges, such as .1–.62 for the first subnet.
Document the plan before configuring devices.
Safety reminders for network administrators
- Follow change management and back up configurations before changes
- Use least privilege and MFA for administrative access
- Patch systems promptly within approved windows
- Lift heavy equipment safely and follow electrical safety in server rooms
Key terms
LAN / WAN · Router · Switch · VLAN · Subnet · IP address: see the full network administrator glossary.