I have an ASUS AC3200 router and use parental controls to lock out my kids devices after a certain time. It worked well until they figured out some sort of VPN program/software that allows them to be on at all hours of the night. Putting aside discipline, unplugging the router and taking their devices away, is there anyway I can block them from using VPN to get on? I tried researching online and the ASUS interface as well but don't quite understand everything being said (VPN server vs VPN client; Open VPN vs PPTP). Any help is greatly appreciated.