Comment 24 for bug 2036358

re: "you should not have both services running"

Is this documented somewhere? What software or script, during system installation, is meant to ensure this? I have not seen warnings emitted from postinst (as added for /etc/network/interfaces) or service start.

I am not certain it needs to be, as
A) wait for any/all managed interfaces in configuring state and
B) wait for any/all unmanaged interfaces
appear to be sufficiently distinguishable cases to let systemd do A without also doing B, with or without the (orthogonal) "any" modifier.