Comment 7 for bug 1598081

I agree once more drivers should be responsible for port states, and hence approach 3 (in comment #3). Although I still see a gap that prevents other systems (e.g. monitoring systems) to report failures to Neutron and thus approach 4 (as a new Neutron service plugin) could help fill that gap. Infrastructures may use those external systems because either the SDN controller may not support reporting of failures or its Neutron driver not support receiving those notifications (i.e. does not implement approach 3) or even because the faulty network infrastructure may not be managed by an SDN controller.

It does not need to be an either-or situation between the mentioned approaches. I am saying there is potentially space and need for both approach 3 and 4.