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VLAN Planner
For a network that already exists. Write down what you actually run, and find out what is wrong with it before it finds you.
Local toolYour network plan stays in your browser. Nothing you enter is uploaded, logged, or sent to any server.
Findings
What gets checked
The same rules the designer applies, run against a scheme you already have. The point is that documentation drifts from reality, and the drift is where faults live.
- Duplicate VLAN IDs, and duplicate names, which make documentation ambiguous.
- Overlapping or identical subnets across VLANs.
- Gateways outside their subnet, or set to the network or broadcast address.
- DHCP ranges outside the subnet, reversed, including reserved addresses, or covering the gateway.
- Subnets above 85% full, where there is no room for a replacement device.
- VLAN 1 in use for user traffic, and IDs in the reserved 1002–1005 range.
Nothing here talks to your switches. It checks the plan as written, which is the document the next engineer will work from.
Related tools
VLAN + Subnet Designer allocates a scheme from scratch. Trunk Visualizer covers tagging between switches.