LDWin tells you which switch and switch port a network cable is plugged into, by listening for the link-discovery announcements (CDP / LLDP) that the directly-connected switch broadcasts. No more tracing cables under floors or guessing at patch panels.
This is an updated fork, rewritten in C#, that works on Windows 11 with Core Isolation > Memory Integrity (HVCI) enabled. It captures with Windows' built-in Packet Monitor (pktmon), so there is no capture driver to install.
- Windows 10 version 2004 or later, or Windows 11 — these include Packet Monitor
(
pktmon.exe), which LDWin uses to capture. Nothing else needs installing. - Administrative rights — packet capture requires elevation (LDWin requests it).
Grab the latest LDWin-Setup.exe from the Releases page and
run it. LDWin installs like any other program: it appears in the Start menu (with an
optional desktop shortcut) and can be removed from Settings → Apps. Installing a newer
version over an old one upgrades it in place.
Prefer not to install? LDWin-win-x64.zip on the same page is a portable copy: extract
it and run LDWin.exe as administrator.
Either way it is a self-contained build, so you do not need to install .NET or a capture driver.
- Start the program (it will request administrator rights).
- From the Network Connection drop-down, select the wired adapter the cable is plugged into.
- Click Get Link Data.
- LDWin listens for CDP/LLDP announcements for up to 60 seconds. Each switch appears in the results panel as soon as its announcement arrives, with its name, port, management address, VLAN, platform and more; listening continues in case more than one switch is on the link. Click Stop once you have what you need.
- Use Save Link Data to write the results to a text file, or Copy to put them on the clipboard.
Switches typically announce every 30 (LLDP) to 60 (CDP) seconds. If nothing turns up, tick Keep listening until found and LDWin will keep retrying until a switch announces itself or you click Stop. A valid TCP/IP address is not required to receive link information.
Link discovery does not work over Wi-Fi. A switch sends CDP/LLDP only to whatever is directly plugged into its port — the access point, not your laptop — and access points do not relay those announcements over the air. Wi-Fi adapters are labelled (Wi-Fi) in the drop-down; selecting one shows your current access point connection (network name, access point BSSID, signal and link speed) instead.
On Windows 11 24H2 and later, Windows only shares those Wi-Fi details with apps allowed to use location. If LDWin says access was blocked, turn on Settings → Privacy & security → Location → Location services and Let desktop apps access your location.
LDWin uses Windows Packet Monitor (pktmon), which ships with Windows and works with Core
Isolation / Memory Integrity enabled. For each capture it tells Packet Monitor to log only
LLDP and CDP frames on the selected adapter, reads them live as they arrive, and stops the
capture when done.
Packet Monitor runs one capture at a time system-wide, so while LDWin is listening it takes
over Packet Monitor: it replaces any pktmon filters you have set and clears them afterwards.
If a Packet Monitor capture is already running (for example one left over from an
earlier session), LDWin stops it and starts its own.
LDWin was originally created by Chris Hall (2010–2014). Original repository: https://github.com/chall32/LDWin