In the thin-coax ethernet days, pretty standard tool in the bag was a Fluke[1] portable Time Domain Reflexomter to do this. Much more precise than the NIC base

In the thin-coax ethernet days, pretty standard tool in the bag was a Fluke[1] portable Time Domain Reflexomter to do this. Much more precise than the NIC based measurements. Very useful for finding exactly where someones 'cable management' ended up nailing through the coax, or where someone ignored bend radius limits when installing. [1] Other vendors made them...I just always had a Fluke