Comment 2 for bug 2060311

There has been confusion in this area in the past. But the stance of upstream is that RequiredForOnline=no => "interface is _ignored_ by systemd-networkd-wait-online". Hence, if every interface is optional: true, it is expected that systemd-networkd-wait-online will timeout.

I have recently suggested that netplan moves to a strategy where if interface ethX is optional:false, then enable <email address hidden>. And, if ethX has optional: true, then do nothing (namely do _not_ set RequiredForOnline=no). We probably need to then either disable systemd-networkd-wait-online.service by default, or change the default flags.