How to route several devices in my network through a hardware VPN device, by changing the gateway?

Question

I have a network at home with a 60Mbit cable connection to the internet via a modem I can't access (supplied and maintained by my Internet provider).

Behind the modem I have a netgear WNDR3700 wireless router, that has enough throughput for my connection. Behind the netgear there are a couple of switches in different locations around the house with different devices attached.

I have recenty purchased a Netgear FVS318G Firewall with VPN, so I can tunnel to a VPN network. The thing is this FVS318G only has 25Mbit LAN/WAN throughput, and 7Mbit VPN throughput, so I don't want to use it for every connection from my network to the Internet. Because of this I can't just put it in between my network and my WNDR3700, because it would slow down all traffic.

I was wondering if there is a way to integrate the firewall into my existing network, so that it's possible to route traffic either through the firewall, or directly to the WNDR3700, by changing the gateway. If possible, without an extra router between the two devices...

My current network is in the 192.168.2.x range, with the WNDR3700 at 192.168.2.1. I was thinking I could configure the firewall WAN port to connect to one of the ports of the WNDR3700, say on 192.168.2.101 and configure the LAN to be in a different range, say 10.0.0.x

If I did that, ofcourse, I would have to physically change connections of any device I want to go through the firewall to connect to one of the LAN ports of the firewall.

So I was then wondering if it would also be possible to reconnect one of the LAN ports of the firewall back to the WNDR3700, and have the WNDR3700 route any traffic for 10.0.0.x to the firewall, which then routes back to the WNDR3700 and onto the Internet. Sort of creating a 'loop' with the firewall in between, whereby a 10.0.0.1 gateway would route me through the firewall, and a 192.168.2.1 gateway directly to the Internet.

Does anyone know if such a setup is possible, do I have alternative options, besides shelling out for new hardware?

Thanks for any pointers

Answer 1

Did you try 'loop' solution? It may not be bad, when your router and OS of your machines correctly implement ICMP redirect. Outgoing traffic wise first packet hits your router and subsequent packet automatically hits your firewall. Return traffic of course flows from your firewall to your hosts direct.