Model :

Hardware Version : Not Clear

Firmware Version : Latest

ISP : BT

I recently migrated to BT Infinity with some static IPs and I am tearing my hear out trying to work out how to use them.

With previous ISPs once I connected to ADSL I was allocated one of my static IPs and it was trivial to use the others as I needed to.
With BT when I connect to their VDSL service I am allocated a random IP with a corresponding gateway which is separate from my static IP/gateway allocation.

I have my own firewall which I want to use in place of BT's hub but I can't see how to pick up the random IP and then use the statics on it because I can't set a different default gateway.

I bought the W9970 so that I could go firewall (one static IP) -> W9970 (bridged or static IP?) -> BT network but I can't get it working. I admit I am not at all familiar with the W9970 so I may be missing something completely obvious.

I can connect to the VDSL service with no problem but I then tried creating an additional 'Bridge' WAN port - which claims to be connected - but I can't access the static IP Gateway from a laptop configured with the correct static IP and subnet.

I then tried creating an interface group with one LAN port (static IP/network) and the bridged WAN but that didn't work either.

Am I overthinking it or missing something? Is there a way to make this work or am I wasting my time and will have to succumb to the BT hub?

Thanks for any advice.