In order to close this issue I want to let everybody know that the source of
the problem was finally identified.
It was not Trisquel, nor the kernel, module/driver, neither NIC or cable: The
malfunction was in the port of the router that was in use.
The router has 4 ports for Ethernet cable and the laptop was using port 2.
This port has proven to have a random behavior (sometimes connect, sometimes
not, and the speed is low, etc.).
Using any other of the ports solve all the issues, for any kernel and distro.
So, could anybody give me an idea about which would be the better way to go
back to the normal Trisquel kernel?
Thanks a lot for everything to everybody!
