I had a problem where every morning I would sit down at my workstation to start the day and I would have to re-sign in to all my Google accounts because at some point after I left that workstation the previous day all those authenticated sessions would be invalidated for some reason.

It wasn’t like this would happen some time in the night either: I also saw it during the day, though less often. Some amount of idle time caused this and I couldn’t figure out why.

Originally I thought this was due to Energy Efficient Ethernet:

Energy-Efficient Ethernet (EEE) is a set of enhancements to … Ethernet physical-layer variants that reduce power consumption during periods of low data activity.

I figured that if Chromium couldn’t heartbeat to Google then that would invalidate the authenticated session. I spent some amount of time attempting to disable EEE to no avail:

$ sudo ethtool --show-eee eno1
EEE settings for eno1:
    EEE status: enabled - active
    Tx LPI: 17 (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

$ sudo ethtool --set-eee eno1 eee off

$ sudo ethtool --show-eee eno1
EEE settings for eno1:
    EEE status: disabled
    Tx LPI: 17 (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

This didn’t help, and it wasn’t even a setting that survived reboots! I also tried to explicitly set the SmartPowerDownEnable setting for the module, which would have not allowed the PHY to turn off in a lower power state:

$ cat /etc/modprobe.d/e1000e.conf
options e1000e SmartPowerDownEnable=0

This didn’t help either. Turns out the behaviour was due to a Chromium setting!

Settings > You and Google > Sync and Google services > Allow Chromium sign-in was enabled for me, and disabling it worked: my Google sessions are not signed out any more. Really this should be disabled by default, not enabled.