Tracing out Live Network Cables

This clever trick helps you identify un-marked network outlets. A Toner and Tone-probel will not work when a network jack is connected to a live switch port in the server room (switch room). By using a simple batch file running on a laptop, you can create a beaconing effect using the swithes link lights.

If you have ever tried to identify an unknown network location by using a toner and probe, you may have experienced the problem of not being able to trace the tone back in the server room (or, whatever you call the room where you keep the patch panels and switches). This is because if the network port is plugged into an active Network Switch port, the tonner stops working. This makes it pretty much impossible to use the toner and probe to identify your network cable.

The solution outlined in the video uses a simple DOS batch file running on a laptop to turn the network adapter on/off in a rhthymic fashion. This causes the link on light on the switch (in the server room) to turn on/off in a matching cadence. While the laptop is plugged into your Un-identified network outlet and running the batch file, you need to be in the server room looking at the link lights on the switches.

This may take a few minutes, but it’s going to work way better than the tonner/probe approach.

Now, if you’re really fancy and you have access to the Cisco command prompt (assuming you have manageable switches), then you could simply plug in any network device and do a search for the mac address. If you know how to do that, then knock yourself out. This video is just proposing a simple solution for those trying to solve a problem. Often times, as network repair personel, even though we do know how to search for the mac address in the switch, we’re usually not given that level of access.

You can get a sample batch file from the Network Advisor website in the tools section. Warning though, windows security sees batch files as potentially harmful files, so downloading, editing, saving may be tricky. I suggests turning off the WINDOWS ACCESS CONTROLS while working with the batch file.

The following batch file is known to work with Windows 7 and Windows 10. I tried it on XP and it said the parameters were invalid.

The batch file looks like this:
netsh interface set interface “ethernet 2” admin=disable

netsh interface set interface “ethernet 2” admin=enable


Goto Begin


HELLO!!!! READ THIS ::::: You will need to edit the batch file and replace the network interface name in the “Quotes” to match the network name of the one on your computer.

And, in case you’re wondering, the PING is just in there to provide a delay. Yes, you can use other methods like TIMEOUT and SLEEP.

If you’re having trouble with the batch file, try doing some internet searches, there is a wealth of information out there.


Randall Lyons says:

Fluke makes a network toner that will trace a home run live cable back to a switch, even a managed switck. It’s called a intelliprobe lan 200. Runs about 250 to 300 dollars.

S Row says:

Wish I could do this but my clients use port security.

alan eagers says:

sh mac address-table | include “your Mac Address”

Robert Purvis says:

I was wondering if you could answer a question. i have tried many times to trace a line on a live network many times without success. i own a fluke microscanner that has the intellitone built in. sometimes it works sometimes it doesn’t. does not work on poe ports. just shows you it is a poe on the screen briefly then screen info goes away. i then have to try the old trick of plugging in a laptop, unplugging it, and having a partner look for it to go away. not so easy with 10 switches in a rack and patch cables blocking your view. i just did a job last night where i was hired to re lace 50 cubicle seats with the lines already plugged in a poe switch on the other end. no labels on the cable. if i have to go back what do i do? i was thinking of either buying just the intellitone generator and not use the one in the microsanner. $135 maybe it will work. other option was the buy the platinum tools cable prowler. i think that is the tester that you can set the frequency and cause a flash at the switch that is very constant and different from the other lights. very similar to what you just described in this video. the way it flashes the light is way more obvious than the flashes i just watched on your video. nonetheless i feel this will take hours. that tester is about $500 btw. grrrrrrr.

Aric Vogel says:

Great idea, this will come in handy for sure.

Brian Coverstone says:

If you want to tone a live cable plugged into a switch, recrimp the toner end so instead of being on the blue / white-blue pair, it will be on blue / brown pair. Basically, hop it over one wire so it runs unbalanced.

Антон Южаков says:

I think you can also use these colors for identifying port by changing the speed of a port, so you would see changing colors which doesn’t happen in normal operation.

NoNoLabs says:

If I may put “timeout 5” between each netsh command and remove the ping. That way the port will be off for a little bit more time and the light will fluctuate like it has issues.

AndDrewskY says:

What would you do if your getting POE, no data / Ethernet?

Ainul Ahmed says:

You rock my friend! Thanks a million!

Dylan Cruz says:

@echo off
color 0A
goto check_adm_perm
title Checking Perms…
echo Administrative permissions required. Detecting permissions…

net session >nul 2>&1
if %errorLevel% == 0 (
echo Success: Administrative permissions confirmed.
) else (
echo Failure: Please run this file as an Admin.
title BeaconBatch V1.1 – Menu
color 0A
echo 1: Start BeaconBatch
echo 2: Exit
set /p opt=”Option: ”
if %opt%==”1″ goto si
if %opt%==”2″ goto exit
title BeaconBatch V1.1 – Select Interface
echo – Select Interface
set /p interface=”Interface Name: ”
goto t
set /p time=”Time between enable/disable: ”
SET “var=”&for /f “delims=0123456789” %%i in (“%time%”) do set var=%%i
if defined var (goto nv) else (goto v)
echo – ERR %time% Invaild!
goto t
echo – SET %time%.%interface% : OK
set t=0
goto b
echo – Interface Set
goto b
title BeaconBatch V1.1 – Cycle [——–]
color 0C
echo Disabling %interface% Interface…
title BeaconBatch V1.1 – Cycle [INACTIVE %interface%]
netsh interface set interface “%interface%” admin=disable
echo Enabling %interface% Interface…
title BeaconBatch V1.1 – Cycle [ACTIVE %interface%]
netsh interface set interface “%interface%” admin=enable
set /a t=%t%+1
echo – TOTAL CYCLES = %t%
TIMEOUT /T %time% /NOBREAK >nul
echo – Cycle Comp
goto b

delvadin25 says:

Love this simple trace – put a Rem in front the Ping “Rem Ping”, and get a quicker noticeable ON/OFF result. Thanks a lot.

Garegin Asatryan says:

Stupid question but you can turn off all the switches and then it won’t have the live issue, right?

SyberPrepper says:

Great tips. Thanks.

Dylan Cruz says:

Hey! I made a edit to the Batch Code. More advanced now!

Jon Vincent says:

I’m surprised you haven’t turned portfast on in your Cisco switch.

BHBalast says:

Graet, thanks.

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