NAT for trusted interface
We currently have a Firebox M400 which has two external interfaces directed to two separate ADSL services and they provide internet connection to two trusted interfaces via multiWAN and crossed failover configuration.
For the next step in order to replace one of the routers that is downstream on one of the trusted interfaces and has a single IP (e.g. 10.0.0.3), we would need to have NAT in that interface to route traffic to packets coming from three different subnets (e.g. 10.1.0.0/24, 10.2.0.0/24, 10.3.0.0/24).
From what I have seen, the Firebox allows to setup NAT only for external interfaces (I am probably wrong with this, as I am a newbie).
Is there a way to assign NAT to run in this trusted interface, in order to make it work as the old router? The TP-Link router that we want to replace calls this feature 'Multi-nets NAT', but I am not sure which is the correct name.