Moving back to NM :)
ifupdown never does anything for interfaces that aren't listed in /etc/network/interfaces
It's Network Manager that's calling the up/post-up scripts through /etc/NetworkManager/dispatcher.d/01ifupdown
One of these, /etc/network/if-up.d/upstart emits net-device-up. I did a quick check and this script hasn't changed since at least Oneiric.
Moving back to NM :)
ifupdown never does anything for interfaces that aren't listed in /etc/network/ interfaces
It's Network Manager that's calling the up/post-up scripts through /etc/NetworkMan ager/dispatcher .d/01ifupdown
One of these, /etc/network/ if-up.d/ upstart emits net-device-up. I did a quick check and this script hasn't changed since at least Oneiric.