You don't even need to go so far as to sniff traffic on any interface. Most linux distros have either lldpd or lldapad built in which gives a bit higher-level i

You don't even need to go so far as to sniff traffic on any interface. Most linux distros have either lldpd or lldapad built in which gives a bit higher-level interface to the raw LLDP data on the wire. The BSDs also have it. Bi-directional so info can be updated switch-side too. I've used it in combination with other tools, DHCP and whatnot to do something similar to what she wrote about, have individual machines 'know' where they are in a cabinet or facility and change functionality based on that. Works great!