My Asus P5WDG2 WS Professional comes with two Marvell gigabit LAN ports, which allow the user to run the Virtual Cable Tester (VCT) control panel/application from Marvell. I can't figure out the proper way to use it. I would have thought that you just plug the cable to be tested into both ports and run the app, but it doesn't work that way. The instructions say: "A test can be performed only if the corresponding network controller does not have a link up". If you connect the cable to both ports that way, you do have a link up. How can I use this thing? How do you connect the cable yet keep the link down?