Diagnose network connectivity loss

A linux workstation suddenly lost network connection.

The cable is connected and the LED's are lit.

ifconfig only shows the loopback interface lo.

Another workstation with the same configurations correctly shows eth2, lo and wlan1 using ifconfig.

How could I proceed to trouble shoot ?

• It could be a hardware problem. How could I test if the networkcard is detected ?


• Somehow the network was disabled (although the standard session opens on a webpage, and thus the only way to change any setting would be Alt-Ctrl-F1 and log into the terminal). I therefore can almost exclude a configuration change unless it was done by a malicious user. How could I test if the network was disabled and reenable it ?