“Energy Efficient Ethernet” (EEE) is mentioned as another possible root cause for the observed behaviour and is enabled in Angström per default:
root@apalis-tk1:~# ethtool --show-eee enp1s0 EEE Settings for enp1s0: EEE status: enabled - active Tx LPI: 0 (us) Supported EEE link modes: 100baseT/Full 1000baseT/Full Advertised EEE link modes: 100baseT/Full 1000baseT/Full Link partner advertised EEE link modes: 100baseT/Full 1000baseT/Full
I disabled EEE with
ethtool --set-eee enp1s0 eee off termporarily. I connected/reconnected the ethernet cable to from/to the switch over and over again and was not able to reproduce the missing link (the behaviour observed of my colleague).
Unfortunately I am not able to test the same in the warm-start and cold-start scenarios because the EEE configuration is enabled again after every
reset or power cycle.
Do you know how to disable EEE persistently over reboots?