Tracing Network Cables with CDP (January 23, 2015)
Over the years I have more then once found myself in the position of needing to trace a cable/jack back to the switch its plugged into. Often this is because the label is missing, wrong, illegible or simply never existed. There are a number of ways to do this and every method has its pros and cons. But if you happen to be in the lucky scenario where 1. the cable is plugged into a switch and 2. the switch speaks CDP you can use this to your advantage.
Simply, take a laptop loaded with a CDP client and let the CDP broadcast from the switch tell you what port (and switch) you’re plugged into. What could be hours tracking wire threw conduit and ceilings or checking the MAC tables on switches should only take a couple minutes.