With a complete path from working switch to USB-C connector already set up, I just plug the USB-C connector into the Librem 5 and it all works.
Or if I do it the other way, as I did the other day, (plug empty ethernet USB dongle in to Librem 5, then connect Cat 5 cable from switch to dongle) it also works.
Potential difference: I am running standard byzantium
Potential difference: Not a Realtek ethernet chip in my dongle AFAIK.
Edit: PS That’s with two different USB ethernet dongles (one GbE, the other FE, probably different ethernet chips from each other but probably neither a Realtek).
In either case, I also have WiFi connected (switched on and associated) at the time, which is both a good thing and a bad thing for testing.
Thanks for the link to earlier kernels, I was digging and digging in the forums for that link and couldn’t find it.
Here is a pastebin of the journalctl -xf output when plugging in the USB-C Ethernet adapter. View paste UQ7A
here is the lsusb output after inserting the adapter
$ lsusb
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 003: ID 0424:4041 Microchip Technology, Inc. (formerly SMSC) Hub and media card controller
Bus 001 Device 002: ID 0424:2640 Microchip Technology, Inc. (formerly SMSC) USB 2.0 Hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
I only wanted to provide a detailed option for troubleshooting. You are right, it is unlikely that others will see this behaviour and it is still possible my troubleshooting somehow missed something. This one was non-obvious to me so hope it helps someone when they search.