NetOpsT

NETWORKING / VLSM

VLSM Planner

Allocate multiple subnet sizes inside one IPv4 address block.

Runs locally

Enter each subnet's host requirement. Largest networks are allocated first.

SubnetNetworkUsable rangeHosts
Subnet 1Requested: 12010.20.0.0/2510.20.0.1 – 10.20.0.126Broadcast: 10.20.0.127126
Subnet 2Requested: 6010.20.0.128/2610.20.0.129 – 10.20.0.190Broadcast: 10.20.0.19162
Subnet 3Requested: 2510.20.0.192/2710.20.0.193 – 10.20.0.222Broadcast: 10.20.0.22330
Subnet 4Requested: 1010.20.0.224/2810.20.0.225 – 10.20.0.238Broadcast: 10.20.0.23914

Networking TOOL

VLSM Planner

Allocate multiple subnet sizes inside one IPv4 address block.

When to use this tool

Use VLSM to turn one parent network into efficient, non-overlapping subnets.

Use it in three steps

  1. Enter the parent CIDR and the host requirements for each subnet.
  2. Review the calculated values against your environment and its requirements.
  3. Copy or document the result only after validating it for production use.

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