I have the following hardware: a computer with 1 ethernet port. A 5-port ethernet switch and a silicondust tuner (which has for an output, an ethernet port). A "smart" tv with an ethernet port.

I have installed Ubuntu ver. 12.04. I have installed MythTV. I have installed the applet Network Manager (hereafter abbreviated nm).

The nm shows only the wifi "Active Network Connection". The ethernet cables run like this: from the computer to the ethernet switch. From the silicondust tuner to the ethernet switch. From the ethernet switch to the TV's ethernet port.

The nm used to show some ethernet info, such as: IP address and mask, but that has vanished and I don't know how to get it back. And I've been trying to get it back for over a week.