cnMaestro and 3 networks

We know why adding a second network interface all radio traffic would have to hit this second one. However we have an issue where we have a private Network and need to have those radios hit the server. I just want to make sure that this is entirely possible by adding the 3rd inteface and setting up routes.

Second interface has never worked for us with cnMaestro. The best way is to sub-interface. Let me know which version of cnMaestro you are using - can provide sample network config.