I am not currently using the Net Balancer, and therefore not familiar with configuring it. But, I am familiar with the idea of connecting more than one ISP where each would have a gateway address that was on the ISP side of the interface connected to that ISP. That is not the situation here.
There is just one ISP and one “gateway” address on the ISP side of the interface. I have multiple IP addresses on my side of the interface. But, my IP addresses cannot be gateway addresses. If I add one of those addresses as a gateway address in the Net Balancer it immediately goes into the Fault state because I have created a route to the edge of my device, but not to the ISP.
I’m obviously missing something.
What I need is to modify the NAT translation process, so that packets destined from a particular internal device to the outside get a NAT translation showing a different edge address as the “source” of the outbound packet from the perspective of the internet.