We have a firebox III that is configured for routed mode with an external and trusted network working perfectly. The option port is currently available and my company needs the following. Setting up the option port for pass-through mode that mimics the public ip address needed on the border controller (no private addressing is allowed). I know Sonicwall calls this transparent mode that allows it to act like a layer 2 device. My question boils down to this: does the firebox III have something similiar?