2 Public IP, 2 MAC address, 4 Port NIC, pfSense

Any workaraound besides another switch? ISP fiber with 2 IP addresses authenticated by 2 separate MAC addresses. Fiber modem has one ethernet port. pfSense has a 4 port NIC. Is there anyway to use one cable from the PON (fiber modem) to pfSense and get 2 WANs using 2 MAC addresses? I tried using bridge mode but could not get authentication.

If a MAC address is required for each then you will need two ports on the pfsense.

Thanks for the clarification Tom! I will use a switch and two NIC ports.