Comment 1 for bug 1056437

I agree the external network might benefit from the provider networks extension.

It seems the intention here is to map the external gateway to a physical network if external_network_bridge = ""
So the external gateway, for instance, could be eth0.
Floating IPs and the gateway itself are currently configured as quantum ports on the external network bridge; in this case we'll need to find alternative; configuring multiple IPs on the physical interface is a possibility which is however different from what the agent currently does.

I am thinking whether we can keep the external_network_ bridge and just use the provider network extension to map it to a physical network, or not use it as you propose but instead attach floating IPs to br-int.