I have more than one static IP address on the subnet provided to me by my ISP. So these are defined as IP addresses on the ZS interface connected to the ISP. I use the Virtual Server feature on the router tab to do port-forwarding for specific ports to specific servers on the internal NAT subnet.
This all works fine.
One specific IP address on the external network is defined as the gateway/default route for all outbound packets to the internet. But, I would like packets from an internal server that has inbound traffic coming in on a particular external IP address via port forwarding to use that same IP address for originating outbound traffic as well. Since I don’t know in advance what the destination would be I would have to rely on a default route to carry the packet out. But, I don’t want this to be the normal default route that sends the packet out from the “wrong” external IP address.
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.