Not sure where to post this, so apologies if wrong place. Here's the problem: Cable modem connected to airport extreme on main floor, I have cat 6 cable going from my new airport extreme, about 60 feet to my upstairs office. There at the wall I have another cat 6 cable going from the wall plate to my ethernet port, and I can't get the internet to work. It only works if I connect cat 6 from wall plate to an airport express, then an ethernet cable from airport express to ethernet port one on the mac pro 5,1. It has to go through the airport express to work and I don't know why. It's not the cable from the wall, I've tried connecting directly to the cable going upstairs and still says "unplugged", ideas? Thanks!