I am trying to use a USB-ethernet adapter to give me a second ethernet connection to an xubuntu 14.04 system.
It's detected OK and drivers are loaded but Network Manager goes into a loop repeatedly saying the connection has been established and then saying it's disconnected. It cycles once very few seconds, say 10 seconds or so.
It's set up with a static IP on a different subnet from the 'proper' ethernet.
Does anyone have any idea what might be wrong?