no internet - 16.04 FE/BE

I installed an update this moing with the Software Updater and after the requested reboot, the FE says "Could not coect to master...".

The update was IIRC, Mythbuntu Base.

ifconfig shows eth0 and lo, but NO ip# for eth0.

I check cables, etc.

Then I boot the BE from a USB Linux Mint 17.3 and there is an ip#. Not a hardware problem, right?

What now?

Is anyone else having a problem?

John