Spontaneous Lost Ethernet Connectivity

XPS 410. Can't get to the internet through ethernet cable. Had connectivity 24hrs ago. Blinking orange light at cable plug in point. PC conituously tries to reconnect then states over and over that cable is unplugged. Unplugged cable from desktop and used it to successfully get to internet on two laptops. Rebooted modem, router, and pc with no luck. Changed cable no luck. Connected directly to modem no luck. Ideas?