Minimum OS Versions
macOS (Apple Silicon and Intel)
Windows (x64 and ARM64)
Linux (amd64 and arm64)
Network switch port discovery tool. Captures CDP (Cisco Discovery Protocol), LLDP (Link Layer Discovery Protocol), and MNDP (MikroTik Neighbor Discovery Protocol) packets to identify what switch, port, and VLAN your device is connected to.
📖 Docs: https://packetthrower.github.io/PortFinder/ · 📝 Changelog
4.x is the pure-Rust rewrite. Zed's gpui
replaces the Tauri 2 + Svelte 5 stack from the 3.x line, which is
preserved on the tauri-version
branch. The capture engine (CDP / LLDP / MNDP parsers, BPF helper,
pcap orchestration) ports across unchanged.
What it does
- Select a network interface (or sniff all)
- Choose protocol: CDP (Cisco), LLDP (Aruba, HP, etc.), or MNDP (MikroTik)
- Click Start and PortFinder captures the next discovery packet
- Displays: Switch Name, Switch IP, Switchport, Native VLAN, Voice VLAN, MTU, Switch Model
Result card
After a capture lands:
- Click any value to copy that one field to the clipboard.
- Copy as JSON copies the full result as
serde_json pretty-printed output — same shape portfinder capture --json produces.
- History (N) opens a popover with the last 10 captures (session-scoped by default; opt-in disk persistence via the settings menu). Left-click an entry to restore it to the card; right-click to copy that entry as JSON.
Keyboard shortcuts
| Action | macOS | Linux / Windows |
|---|
| Start / Stop capture | ⌘R | Ctrl+R |
| Quit | ⌘Q | Alt+F4 |
Settings
A hamburger menu in the title bar opens the settings panel:
- Save capture history — when on, the in-app history popover persists to
history.json alongside settings.json. Default off; flipping the toggle off deletes the file (in-memory deque stays for the rest of the session).
- Log level — slider with three stops (Normal / Verbose / Trace). Applies live to every logger (GUI + any parallel CLI invocation). Default Normal (info-level).
- Write debug log — toggles file logging. Default off; the log file appears only after you flip the switch. Takes effect immediately, no relaunch.
- About → opens an in-popover sub-page with version, GitHub, GPL-3.0 license, and BPF helper / Npcap / capture-access status.
- Settings folder / Log folder buttons reveal the platform-conventional directories in your file manager.
Log file location per platform:
- macOS:
~/Library/Logs/PortFinder/portfinder.log (Console.app indexes it)
- Linux:
~/.local/state/portfinder/portfinder.log
- Windows:
%LOCALAPPDATA%\PortFinder\Logs\portfinder.log
CLI
The headless CLI shares the capture engine with the GUI. Run with no args to launch the GUI; pass a subcommand to use the CLI.
portfinder capture --interface en0 --protocol LLDP # capture and print
portfinder capture --json # machine-readable
portfinder list --with-ip # interfaces with IPs
portfinder privileges # diagnose access
portfinder --help # see all options
Global flags work alongside any subcommand:
-v / -vv — bump log verbosity to debug / trace-q — warnings + errors only--log-file <PATH> — override the platform-default log path for this invocation (process-scoped, doesn't touch persisted settings)
This is the beginning of the README. Read the rest at the original. Read the full README ↗
