I have Ubuntu 12.04. My LAN port was working well and good till yesterday when I shut down my system. When I wanted to use my laptop today the wired network was not being detected. When the port works the blue light glows as an indicator but right now just an orange light indicating failure is glowing.
This light keeps glowing and tries to connect even when I have removed my LAN cable. The output of
sudo rfkill list all shows nothing is blocked. Also even when LAN used to work in Ubuntu it did not work in Windows 7.