Make the lights of your NIC blink
If you work on a large network and you get sent to the server room to check out a certain network card, you might get lost in the multitude of network hardware. To find your certain NIC, SSH to the machine in question and do a
sudo ethtool -o eth0
The lights of the network card should start blinking repeatedly.
it should be (ethtool version 6):
sudo ethtool -p eth0 [N]
or
sudo ethtool --identify eht0 [N]
you can set a timeout in seconds [N] after the device name