ethernetinternetnetwork-managernetworkingserver
I wanted to install Ubuntu 20.04.3 LTS Server but everytime I get to the network connections it shows only wifi even tho I already plugged in an ethernet cable, it also wont show any way to set it to ethernet. I continued without a network connection but then I dont have access to internet even after trying to enable it with /etc/network/interface but ifup isnt pre-installed and when checking eth0 it wont find it.
How do I make it use ethernet?
Note: I'm posting this workaround as an answer due to the number of times this has been reported as a bug only to expire shortly thereafter and resurface again.
Test
Enter Ubuntu recovery mode: a. Power on system and press Shift during boot up for GRUB menu.
b. Choose "Advanced options for Ubuntu" > Ubuntu, [kernel version] (recovery mode)
Choose "root" and key in below commands:
rmmod forcedeth
modprobe forcedeth msi=0 msix=0
exit
Choose "resume" to resume normal boot
Now the network should be OK till next boot with AM3+ CPU.
If the workaround works on your system, please modify below file to automatically run the script when boot up:
Bug Workaround Solution:
Add the line exec rmmod forcedeth at next line of "script" (above grep?) in the file /etc/init/module-init-tools.conf or /etc/init/kmod.conf)
Add the line modprobe forcedeth msi=0 msix=0 to /etc/rc.local
Restart the system to verify
Sources: Primarily Achkap post #16 http://ubuntuforums.org/showthread.php?t=2020571&page=2
https://bugs.launchpad.net/ubuntu/+s...x/+bug/1003297
https://bugs.launchpad.net/ubuntu/+bug/1264509
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1281930
Clue from Julian Uribe in comments.
Open the terminal application and type:
nm-connection-editor
On the window that opens, select your Wired Connection and click the gear icon at the bottom of the window to edit it. You need to select the General tab, enable "Connect automatically with priority", and change the priority to 1. This will prioritize the ethernet connection.
Understand that:
Ubuntu normally auto-selects the connection with the best performance.
If you have an ethernet connectivity problem, that would explain why your connections keep on switching.
Check that your USB-C port doesn't power itself down at idle... you may have to check BIOS settings for that.
Best Answer
I managed to solve it like this:
First I checked the network devices
It said that my network device is UNCLAIMED so I searched for a driver for my network chip, found and followed this:
https://wiki.ubuntuusers.de/Howto/Realtek-r8125/
after reboot it finally worked as intended.