I have connected an Arduino Mgea 2560 and an ethernet shield and have a working webserver but it randomly stops talking to the ethernet. The time it is running ok might be minutes or even many hours but probably no more than a couple of days at most. Pressing reset on the Arduino or the ethernet shield does not restore operations but a full power cycle does. Obviously it could be code but it could be something in the ethernet chip itself. Has anyone else had this kind of behaviour and was there a cure? I have tried adding a watchdog based on ethernet coms but that doesn't appear to help. Is there any kind of hardware available to do a hard reset (power cycle) other than my own fair hand?