How to configure traffic routing on a laptop?

Question

VPN

There is a home network, which consists of a router and several home computers and devices connected to it. Subnet 192.168.1.0.
VPN rises on one of the computers (windows 7), from which you can see the subnet behind the VPN. Subnet 172.XX.XX.
I would like all home devices to also see the subnet behind the VPN.
The first thing I did was add a route on the router that all requests for the IP subnet 172.XX.XX went to the laptop where the VPN was up.
How to configure traffic routing on a laptop?
Tracing reaches a computer with a VPN, and stops there.

Answer 1

Not only does the packet from your home device reach the network behind the VPN - you can really do this.
It is necessary that the return packet from the computer from the network 172. returned to your home device. And that remote computer knows nothing about the 192.168 network. and will never know (unless you are an admin on the other side of the tunnel).
In fact, at the time of raising the VPN tunnel, your laptop was assigned an address from the 172. network, which allows other computers on the far network to communicate with it.
Therefore, we need NAT on a laptop that would remember the internal IP of each outgoing packet, replace it with its 172nd and return everything in the opposite direction.

Answer 2

Well, Windows 7 itself, as far as I remember, cannot work in router mode. Just turn on ICS and make NAT to the network 172.xxx And on other devices, set a route like this:
172.xxx mask 255.0.0.0 [IP of the computer with the VPN]
If the router allows (which I doubt, but still), then it's better make a separate routing environment between it and the VPN computer. Not necessarily physically isolated, you can simply give a second IP to each interface. Otherwise, routing between devices and the 172.xxx network will not work without changing the settings of the devices themselves.