I'm sure that if I could make a decent job of explaining what I mean I could Google for this but...
My PC is (say) 192.168.1.10, and it can access a remote device (192.168.2.100) via a VPN.
What I want to do is give my PC an extra IP address (eg 192.168.1.11) and map all network traffic to that IP address (on any port, and including broadcast traffic) to 192.168.2.100, and send any responses back.
In doing so, any other PC on my LAN would be able to access the remote device as if it were local (192.168.1.11).
Can I do this?
(Background: In this case I have some brain-dead Windows configuration software that can only talk to devices on the LAN, so I need to make the remote device appear as if it were on the LAN. However I have had similar challenges in the past where using a local Linux box as a conduit to remote devices would have been useful.)
If relevant, whilst 192.168.2.100 is not a Linux PC (it's an industrial I/O unit), I do have a Linux PC on the remote network that could form part of the tunnel if required. The key point is that I need the remote unit to appear to be on the local network, not just to be accessible from it. My Windows PC can ping (etc) the remote unit fine via the VPN itself, but the configuration software will only search for and work with devices on 192.168.1.0/24, so I need to fake it.