stupid networking question

[arne anka]

> So if you have both "allow-hotplug" and "auto" for the same interface,
> it just means you want to bring it up at boot and you also want to bring
> it up when it gets plugged in.

while it might not be forbidden, it sounds rather pointless.
if the interface gets up when booting then there's no need to get it up  
(again) when plugging in something.
additionally, one does usually not want usb0 up at boot since it makes  
only sense when a usb networking capable device is plugged in -- so  
allow-hotplug seems the only sensible option,  to me, that is.