I have setup an OpenVPN server on my Asus RT-AC68U router (asuswrt sig ver 1.184) and a client on my laptop.
The good news is that I can externally connect to OpenWebif, which was the object of the exercise.
The bad news is that I can connect to everything else on my home network, including my router.
I just can't see how I can configure the VPN server to restrict external access to a limited range of IP addresses on my home network. Bear in mind that I am limited to configuring via the router's UI, although there is a box for custom configuration.
All help gratefully received.