The machine in question is a Dell t620 and I'm using one of the ethernet ports on the motherboard.
The diagnostics log has these messages:
Aug 23 15:58:34 Tower kernel: igb 0000:06:00.0 eth0: igb: eth0 NIC Link is Down
Aug 23 15:58:34 Tower kernel: br0: port 1(eth0) entered disabled state
Is there a way to block the nic from doing this?
tower-diagnostics-20240823-1747.zip