Windows 2003 Routing.

I have a little problem, and cant see what it wrong.

I have a complete Virtual Environment of 7 servers with there own Domain Controller etc running on a VMNet 7

I need the entire environment to be able to get out on to the real network, but do not have enough real IP addresses and do not want most of the traffic to go on the main network. 

So thought I would create a machine to act as a Router using Windows 2003 Routing.

I have tried to configure the Host with Windows RRAS Lan Routing between the VMNet7 Interface and the real network interface.  But the servers cannot get to anywhere else on the network.  They can ping the LAN network address of the Host but nothing further than that.

I have also tried using on of the Guest machines to act as a router, giving it 2 interfaces, on on the VMNET 7 and one Bridged, but that is exactly the same.

Any ideas, not sure what I am missing.

Thanks

John