How to allow a user to access the network only through a VPN?

Question

Computer networks

There is a windows server2008r2 which connects to the VPN when the user logs in. How to prevent a user from accessing the network not through a VPN? For example, if the VPN server is offline.

Answer 1

Static routing table?

Answer 2

static route + vpn client to autostart (remove user rights to change routing, turn off the client)