There are some really nice features about EX switches, and I only just got round to giving this one a go. You can run a port test – in the screenshots below it is ge-0/0/3 – and one of the tests run will tell you how far it is to the cable break. This is a Time Domain Reflectometer (TDR) test. In the example, it shows 17 metres to the break – so I can tell that there’s probably a cable from the port to the patch panel, but nothing plugged-in at the wall-port.
Browse to the web interface of the switch, log in and click the “Troubleshoot” tab along the top:
Hit the “Troubleshoot port” button and a wizard will start. Select the port you are interested in:
The tests run are a link test, a cable test (the TDR one we are talking about here) and a configuration test:
And here’s our result – cable pair is open at 17 metres from the switch: