MyNet N900 Central Router: the Perpetual Disconnect Machine?

It would seem that the LAN on this particular MyNet N900 Central has some serious issues.  When attempting to connect a cable between the router any any computer, it experiences nearly 50% packet loss from ping, most of them being “general failure” instead of “request timed out”.

EDIT: The problem has been resolved.  A hub device had a loopback connection on two of its ports that was causing artifiical network traffic.  Thanks to everyone who tried to help!