Dual WAN Not Working with Routed LAN Network

[neelim]

Hi,

I am new to OPNSense(coming from sophos environment) and need your suggestions in achieving a specific setup. I have a router(172.16.0.2) connected to the OPT interface of my OPNSense Firewall(172.16.0.1) which transparently passes the traffic to the OPNSense box which in turn does the NAT(through manual NAT rules that I have added) and provides internet access to the clients connected through the router. Basically the router is doing hotspot and vlans etc(172.16.1.0/25, 172.16.2.0/24,172.16.3.0/25,172.16.4.0/24). and it is working fine.

my LAN interface is not having any actual users. It is only used for management.

This setup works when i use only one WAN, but as soon as I and a second interface WAN2 and create gateway fail-over group to achieve multi wan it stops working.

Now I want to know how it can be fixed? Should I change my LAN interface to OPT? or there is some way where I can keep both wan and based on the source network (172.16.1.0/25, 172.16.2.0/23 etc.) or IP address I can use WAN or WAN2 for the traffic?

Thanks in advance