I installed a fresh Tumbleweed 20180114 on my fresh Thinkpad T470s. The
ethernet works during the (network) installation of Tumbleweed but when I boot
the system it does not "work" in the OS itself.

With "work" I mean that there is no link/connection. When I use ethtool on the
interface the command states there is no link (no carrier, Link detected: no).
But when I look at the hardware itself I can see that one LED out of two is
green: the hardware detects the cable.

I reseted the interface using the ethtool but this did not work but then I did:

ethtool -s theinterfacename speed 100 duplex full

And the second LED went from nothing to yellow and the interface suddenly
worked. 

Please note that when I use the same cable with the Docking Station it works
with 1Gbit.