My wired ethernet suddenly stopped working. I have connected my iMac with a cable to my Airport Extreme. Under Network-Ethernet it says "No connection" "cable not conected". I tried several things thusfar: - mount a new ethernet (cat5e) cable - reset NVRAM and PRAM - reset my Airport Extreme - powerdown and startup my entire network - I tried a different port on my Airport Extreme Nothing of this helps. Wifi is working though. And communication between my Airport Extreme and my NAS and modem is also working (both are wired). So, is there a way to test if the ethernet-port on my iMac is OK? Or am I missing something?