J. Fahrner wrote on 27/12/17 06:04:
> [snio]
> eth0 works normal in network-manager. The error is only during boot. I'm
> wondering why ifup tries to activate eth0, since this is not in
> /etc/network/interfaces. Where does this info come from, that it should
> enable eth0? Does it come from udevd?

Yes, eudev has code to test the interfaces from 80-ifupdown.rules, which
causes /lib/idev/ifupdown-hotplug to run, and that will use ifquery for
checking whether the interface concerned has an allow-hotplug in
/etc/network/interfaces.

I would guess that your machine offers a race between the kernel
establishing the interfaces, and the running of ifquery, since the
latter can't find the eventually existing eth0. That's the beauty of
parallelism in the bootstrap.

Assuming the log shows that error systematically, you might test the
situation by adding in a "sleep 1" at the top of
/lib/udev/ifupdown-hotplug, which should make the error go away. If not,
I'm wrong.

If you can "confirm" the problem, please lodge a bug report.

Ralph.