[neutron][OVN] Multiple mechanism drivers

We are looking at using OVN and are having some issues with it in our ML2 environment.

We currently have 2 mechanism drivers in use: linuxbridge and midonet and these work well (midonet is the default tenant network driver for when users create a network)

Adding OVN as a third mechanism driver causes the linuxbridge and midonet networks to stop working in terms of CRUD operations etc. It looks as if the OVN driver thinks it’s the only player and is trying to do things on ports that are in linuxbridge or midonet networks.

Am I missing something here? (We’re using Stein version)

Thanks, Sam