I'm running Ubuntu 21.2 on an Odroid HC2. I'm having difficulty getting ethernet to connect and when connected, stay connected.
"Activation of network connection failed" when attempting to activate the ethernet connection. On the times that it does connect (after a reboot) it won't stay up for long before presenting the same issue.
I have installed the realtek 8125 driver and also tried to use the r8689 driver to no avail.
I believed it was the soldered NIC at fault and so purchased an ethernet to USB 3.1 adapter. That worked out of the box and gave me a few days of connectivity before that too failed.
I've added 1.1.1.1 to /etc/resolv.conf and also added a route 192.168.1.1. According to: https://unix.stackexchange.com/questions/448792/ethernet-connected-but-no-internet-access-on-linux-mint/448845#448845
IPv4 and IPv6 are set to use DHCP.
Any guidance would be appreciated.
Additional Information:
Journalctl NetworkManager log
Oct 18 20:12:05 kepler NetworkManager[12742]: <info> [1634584325.0362] device (enx00e04cb78f90): Activation: starting connection 'USB Ethernet' (95c0d886-80fb-47d0-aed9-a9259f613460)
Oct 18 20:12:05 kepler NetworkManager[12742]: <info> [1634584325.0365] device (enx00e04cb78f90): state change: disconnected -> prepare (reason 'none', sys-iface-state: 'managed')
Oct 18 20:12:05 kepler NetworkManager[12742]: <info> [1634584325.0371] manager: NetworkManager state is now CONNECTING
Oct 18 20:12:05 kepler NetworkManager[12742]: <info> [1634584325.0416] device (enx00e04cb78f90): state change: prepare -> config (reason 'none', sys-iface-state: 'managed')
Oct 18 20:12:05 kepler NetworkManager[12742]: <info> [1634584325.0439] device (enx00e04cb78f90): state change: config -> ip-config (reason 'none', sys-iface-state: 'managed')
Oct 18 20:12:05 kepler NetworkManager[12742]: <info> [1634584325.0445] dhcp4 (enx00e04cb78f90): activation: beginning transaction (timeout in 45 seconds)
Oct 18 20:12:08 kepler NetworkManager[12742]: <info> [1634584328.5079] device (enx00e04cb78f90): carrier: link connected
Edit: I'm able to use a network bridge via the ethernet port from my laptop to connected to the internet. I'm not sure if this helps to diagnose anything.
The linux ethernet drivers are realtek-8125.