We're considering implementing VPN tunnels to allow us to communicate with either one or two servers at a number of outside organizations that we do business with. To do this we need to provide a simple, plug and play solution to those outside organizations.
Can the VPN concentrators be configured to connect to a single subnet - either using only a single interface, or with both the public and private interfaces connected to the same subnet? The thought is that these would be attached only to the segment with the server(s) to which we need to connect, and it would not require change to the network (only the allocation of ports on the LAN) for the addition of the VPN concentrator. Routes would be defined on the server(s) to direct appropriate traffic to the VPN concentrator.
Can the public interface on the VPN concentrator have a private address that is NATed elsewhere on the network for communication across the public Internet?
