I'm an old school telecom/PBX guy, but these days of course involved with networking in a basic form at least with VoIP. I've used a network cable tester after connecting plugs and jacks plenty of times, but Is there a device that could plug into a network jack that would ID the port that it's on? Had a customer who's downsizing that wanted to disconnect phone and data connections in a vacated part of the building. As suspected, most of the data jacks weren't labelled on the patch panel. When toning a cable connected to a PBX line, if a phone couldn't be plugged in to identify the line/port due to it being defective or deactivated I'd use an open pair to be able to hear the tone better. I've had success with hearing a tone on a cable connected to a PBX port, difficult but listening very carefully is not impossible. With a network port though, it brought the tone down to nothing on a given pair. I then put the tone on pins 1 & 4, the test tone seemed to be a bit less muted not being on a dedicated pair. It was very low, but I found it. No luck with others. For those I hated to do this but I ended up by trial & error unplugging network ports that were inactive, a few at a time until the jack was dead. A lot of walking back & forth, sure would have been easier with 2 people to watch network port lights on a device.

Is there some kind of utility on the switch/router that would indicate which port a test device is plugged into, or simply an app for a PC that could indicate the port it's on? Or - something like the intercoms from years ago that would use the house AC wiring to transport audio, maybe it was a carrier signal that rode on the AC wiring. Makes me think of an old 'Carrier Current' AM radio station on a college campus. There's got to be an easier way than what I did today.