I just recently bought a used Thinkpad X200s and installed Xubuntu 13.04 on it. I am have issues getting the ethernet port on the laptop to connect. I also have a Ultrabase dock for the laptop. While docked, the ethernet port on the Ultrabase connects perfectly. Whether the laptop is docked or not the its own ethernet port won't connect. However, the ethernet port on the laptop does light up when a cable is plugged into it when it isn't docked. It doesn't light up at all when it's docked.
My current theory is that because I installed Xubuntu with the laptop docked and the ethernet plugged into the dock this caused port on the laptop to not be setup. From looking at my network settings in xfce it seems that only eth0 is setup and that is the port on the base. Whether the device is docked or not that is the only interface that shows up and when using the dock's port it is connected. Does this mean that the port on the laptop is completely broken or is it a software problem?