WAN/LAN separation

Hi,
Looking at pictures of the nitrowall, it doesn’t seem obvious at first whether there is a WAN/LAN separation on the ethernet port side, i.e. two distinct network interfaces to act as a hardware gateway.

How does the nitrowall handle the WAN<->LAN translation, if there is no dedicated WAN port ?

Cheers

I seem to see from the OPNSense documentation that you can dedicate physical ports to virtual interfaces within the software itself, in which case I would potentially assign a single port on the nitrowall appliance to WAN and the remaining 3 to LAN, all from within the OPNSense configuration tool. Is this correct, do you confirm this is the way to go?