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VLAN & IP Plan Checker

Check a VLAN plan for duplicate IDs, overlapping subnets, and invalid gateway addresses. Work locally without uploading network information.

Runs entirely on your deviceNo uploads, accounts, cookies, or personal tracking.

Review VLAN plan

Local processing · no input storage

Network tools
Tab-separated VLAN ID, name, IPv4 CIDR, gateway. No header row. IDs 1–4094; LAN subnets /30 or larger.

Assumes one VLAN and routing namespace. Separate VRFs and vendor-reserved VLAN IDs require separate review.

Text lists: up to 500 non-empty lines and 256 KiB per field. Tabular results: up to 5,000 rows.

Enter your data, then select review vlan plan.
1. Add your data

Enter your network data or load the worked example.

2. Choose the result

Review VLAN plan and review the result and assumptions.

3. Save it locally

Copy the result or download it for your engineering workflow.

About this tool

Use VLAN & IP Plan Checker without an upload

Check a VLAN plan for duplicate IDs, overlapping subnets, and invalid gateway addresses. Work locally without uploading network information.

The operation runs in the current browser tab. Tool input is not included in aggregate analytics, and the standalone download makes no analytics requests.

Network toolsDeveloper tools