Q:

Gateway / Switch hybrid

Next week I'm getting a new internet connection installed. It comes with 5 static IP addresses by default.
Now, I would like to use some of these IPs on my systems. However, I have more than 5 devices to connect, so I would like to use NAT on one of the IP addresses.
I would like to know if there are devices available that function as a NAT gateway/router, while also functioning as a plain network switch. I have 3 physical locations where I want to connect devices on the wired network, as well as desired support for WLAN (ideally also integrated in the device I'm looking for)
Since I have a few existing cables running through my house, I would like to use those. Basically, I need a device that offers NAT, but is smart enough to properly route other traffic as well.
Note: the Juniper router is owned by my ISP and I'm not allowed to connect more than one device

I'm thinking this might just work out-of-box, but I haven't ever tried it. Thoughts?

A:

What you are after is a Multi-Nat switch. Netgear ships the rather excellent FVS338 Firewall. It's a SPI Firewall + Multi-NAT + 8-port switch, as you can see from the description. The price is very affordable; under 200 USD on most locations.
The switch itself will assign one of your public static IP addresses to its WAN interface. Multi-Nat will then take hold of your remaining IP addresses (4 on your case), if you so wish, by NATing them to internal addresses and maintaining proper connections between NATs with the help of the firewall component. The firewall component is an essential part of this type of configuration and you can establish separate inbound rules to host multiple public IP address and associate those addresses with any local server.
Your drawing would work perfectly and it's basically all you need. That switch closest to your ISP router is what you want to replace with the FVS338.
Alternatively, you can go with a home-made recipe. If you can afford to dedicate an old computer to act as a firewall/switch, you can install Linux on it and use SmoothWall, with the SmoothHost module (which is precisely a multi-nat module). I'm thinking SmoothWall because it's a rather easy to configure firewall solution. But depending on your confidence level in Linux, there's plenty of other options. It remains however the idea that, other than buying an actual device, this can also be made in-house in an old computer.
Best of luck. And have fun!

