Replace Huawei GPON

[Goombadave]

Hey guys,

I have Fiber to the home which terminates with a Huawei GPON HG8040H box that has the fiber input with 4 ethernet ports. 2 of the ports receive a DHCP assigned address from my ISP. I would like to simplify my setup and if possible remove the Huawei GPON from the network. I am not sure if it is possible but hoped the community could help. I have an x520 NIC card with two SFP ports. What I would like to do is simply run the Fiber cable from the ISP into the port on the X520 (using SC to LC cable) and spoofing the Huawei MAC with Opnsense. I think that much would work however how can I go about getting both IP addresses on that interface, particularly if they are DHCP assigned? Is that possible? I think this would be easier if I had static IPs, but that is in itself a bit of a challenge and I would like to try a solution with OPNsense.

Thanks!