Ubuntu Ethernet Configuration

It’s been a long time since I’ve had networking issues with Linux. For the last 10 or 15 years, the Ethernet just seemed to work with most of my hardware.

I updated to Ubuntu 21.10 and my Ethernet stopped working.

Fortunately, I found this post on Reddit, which solved my problem.

Ethernet adapter was disable on Ubuntu 17.04

Edit file /usr/lib/NetworkManager/conf.d/10-globally-managed-devices.conf and change it’s content from :

[keyfile]
unmanaged-devices=*,except:type:wifi,except:type:wwan

To :

[keyfile]
unmanaged-devices=*,except:type:ethernet,except:type:wifi,except:type:wwan

And then run :

sudo service network-manager restart

That solved the problem, but I realized later that Ubuntu was using netplan. I then added this to /etc/netplan/99_config.yaml

network:
  version: 2
  renderer: networkd
  ethernets:
    ens6:
      dhcp4: true
      nameservers:
        addresses: [8.8.8.8, 8.8.4.4]

That solved the problem on system reboot.

More interesting to me is that I got to use lshw, ifconfig, dhclient, and route to trace the problem.

Using lshw -C network, I was able to get the logical name of my Ethernet adapter.

Another command to find the Ethernet interface is ip a.

I was able to bring it up with ifconfig ens6 up

That is a very nostalgic command for me. :-) I’m not sure when the network interfaces moved from the eth0 notation to ens*. That my might be good to track down. If anyone knows hen it changed, drop me a comment below. I think it’s been ens for 5 years on Ubuntu??

Using dhclient ens6, I was able to automatically configure the interface with an IP and routes.

My route table is now looking fine.

I haven’t been keeping up with the changes to Linux networking configuration managers over the past decade.

It was a bit of a trip down memory lane for me to get my Ethernet back up on Ubuntu 21.10 as I sat here at my desk with a cup of coffee.

Another fine Sunday morning with Linux network configuration

Linux Teaches by Giving Us Challenges

Linux is sometimes an interesting beast that teaches us with challenges. I’ve been using wayland for years, not because I find it better, but because I have problems with wayland.

At my age and my current work, I no longer understand the graphics system of Linux. However, it is fun to tinker around when screen capture and screen sharing on video conferences stop working on Wayland.

At my level of hobby, I haven’t made the move to Arch Linux and still wait and see with Ubuntu. I guess that I should install Arch Linux on a spare SSD one day and join the fray on some relaxing Sunday morning.