I am trying to make an iptables gateway. I ordered 3 dedicated server from my hosting company all with dual nics. One server has been given all the ip addresses and is connected directly to the internet and has its other nic connected to a switch where the other servers are all connected also. I want to setup iptables so for example the ip address 50.0.2.4 comes into my gateway server it fowards all the traffic to a private ip address using the second nic. This way the second nic can do what ever it needs and can respond back also. I also want it setup that if any of the other servers needs to download anything over the inernet it is able to do so and by using the same ip address that is used for its incomming traffic.

Lastly I would like to be able to setup dns and other needed networking stuff that i maybe not thinking about.