Comment 5 for bug 1238439

Deleting the external network fails because there is a floating IP on the external network.
It occurs with both OVS and ML2 plugins. I tested with the latest milestone-proposed (= RC2; commit a92b15e198b50f3acb9b6ed634543a0ba386af9c).

In my understanding, a floating IP is not released but disassociated when a VM is terminated,
and the floating IP should be deleted (released) manually.

Currently floating IP on an external network are not deleted automatically when deleting the external network.
I am not sure they should be deleted automatically or not.
Removing the external network is not a usual operation in a deployment (except a lab) and we should delete an external network carefully, so the current behavior sounds reasonable to me.