Stop staring. Start comparing.
Use it now • About & Screenshots • Self-Host Guide
Paste terminal output from your old and new switches. See every MAC address side-by-side with VLAN, port type, description, and CDP neighbor data — mismatches highlighted instantly.
No more eyeballing two terminal windows. No more "stare and compare" until your vision blurs. Paste, click, done.
Every network engineer has been there: you've swapped a switch, moved the cables, and now something doesn't work. A printer landed on the wrong VLAN. A camera port got plugged into a phone port. A trunk lost a device.
The old way: open two terminal windows, run show mac address-table on both, and stare at them until you find the difference. On a 48-port switch with multiple VLANs, that's hundreds of lines.
TRMCompare does the staring for you. One line per MAC address. Old switch on the left, new switch on the right. Mismatches flagged. Filter to issues only. Export for documentation. Move on with your day.
- Multi-command paste — Paste full terminal output including
show mac address-table,show interfaces description,show cdp neighbors, andshow vlan. The tool auto-detects and parses each command. - Side-by-side audit — One row per MAC address. Old switch data on the left, new switch data on the right. MAC address anchored in the center.
- Mismatch detection — VLAN changes, port type changes (access/trunk/voice), description mismatches, and CDP neighbor changes are flagged with color-coded badges.
- Layered port classification — Trunk/Voice/Access detection uses MAC table heuristics,
show vlandefinitive data, and CDP neighbor confirmation for maximum accuracy. - Dark + Light themes — Dark charcoal default for long sessions, plus an eye-friendly blue-gray light mode. Toggle persists across sessions.
- Sortable columns — Click any column header to sort. Sort by old port, new VLAN, description, CDP neighbor, or issues.
- Filter pills — Toggle Trunk, Voice, Access, New, Missing. Click "Issues Only" to hide all OK rows and focus on problems.
- Text search — Type in the filter box to search across all columns.
- Excel + PDF export — One-click export for documentation and handoff.
- 100% client-side — Your data never leaves your browser. No server, no account, no telemetry.
Issues Only — one click hides all OK rows
Visit TRMCompare on GitHub Pages and start pasting.
git clone https://github.com/lbruton/TRMCompare.git
cd TRMCompare
python3 -m http.server 8080
# Open http://localhost:8080ES modules require HTTP serving — file:// won't work due to CORS.
Run these commands on each switch and save the output:
Capture the old switch output before the swap. Capture the new switch output after.
show mac address-table
show interfaces description
show cdp neighbors
show vlan
Only show mac address-table is required. The other commands add enrichment data (descriptions, CDP neighbors, VLAN names, definitive trunk/access classification).
Paste your saved terminal output (from the hostname# prompt to the end) into each panel. The tool handles multi-command output automatically.
Click Compare. The audit table shows one row per MAC address:
| Old Switch | MAC | New Switch | Issues |
|---|---|---|---|
| Port, VLAN, Type, Desc, CDP | aabb.cc00.0201 |
Port, VLAN, Type, Desc, CDP | VLAN, DESC |
Mismatched cells are highlighted. Filter to "Issues Only" to focus on problems.
- Cisco IOS — Catalyst 2960, 3560, 3750, IE-3000
- Cisco IOS-XE — Catalyst 9200, 9300, IE-3300
- Cisco NX-OS — Nexus 3k, 5k, 7k, 9k
The samples/ directory contains example switch output for testing:
before-ie3000.txt— IE-3000 (FastEthernet) with phones, cameras, printer, signage, trunk uplinksafter-ie3300.txt— IE-3300 (GigabitEthernet) after migration with a mispatched printer and missing camera
Zero dependencies. Zero build steps. Zero telemetry.
- Vanilla HTML, CSS, JavaScript (ES modules)
- SheetJS for Excel export (bundled)
- jsPDF + AutoTable for PDF export (bundled)
MIT