Using VPN to connect to one of two sub networks?

[JasonWilliam]

Hi All. I'm a VPN newbie so please pardon me if this is a stupid question.

We sell a product that sits off to the side of a clients current office LAN structure, by creating an entirely separate LAN. For example, if all the users currently have a 192.168.1.x address, our product would come in and be on a 192.168.100.x address. The machines on the .1.x network have Internet access, the .100.x machines do not, however the "server" machine provides a sort of bridge, as it has 2 nics, one for each network. This server would be our gateway in and where (I think) VPN software would reside.

So, how/what VPN do I use to allow my remote machine to access both the .1.x network AND the .100.x network.

One caviat... many of the machines on the .100.x network are not PCs at all, but rather motion controllers, PLCs, data acquisition boxes... the idea behind this whole thing is to provide us a mechanism for remote updating of our individual software components running on these non-PC based devices (we do that thru the development environment of the particular device, however it needs to connect to an IP address to work). Any thoughts? Is this a no brainier?

Is this a software function... something running on our server machine? Or rather, is this a hardware function... a router that has one port for the .1.x network and another port for the .100.x network... I imagine we would need to set up a port forward in the client's current router that points to this new box??

Any help would be greatly appreciated.

 

[JasonWilliam]

Ok after some more reading, I think the following situation best suits my needs:

Get a VPN router like the Linksys RV042. Set this up as a switch for our .100.x network, behind the clients current router. Configure the clients router to port forward (after figuring out what port the Linksys is listening on) to the Linksys. Connect using MS's built in VPN client (does Linksys give you one with the purchase of the router?) Now, in theory, I should be able to connect from anywhere using that client.

One further step would be to have the Default Gateway for the nic set up for our network inside the server machine point to the other .1.x network. That way, our network can see all the .1.x machines, but the .1.x machines cannot see our .100.x machines.

Am I on the right track??