there is no bridging involved. The setup was* fully routed.
I could try using another interface, but the RB was* outdoors on a rooftop, a good 20m away from the nearest power source, I would need a way to power the board, and since there is only 1 port which supports PoE, I couldn’t have done this without keeping the unit open.
NOTE: I say ‘WAS’ because client ultimately refused the whole thing and we ended up with a couple of antennas smiling at us and an unhappy customer.