Be cautious, even if it’s simple to set up your head server with the Kali Linux (shown experiment) in fact most people that would use it, is ISP -- you can also ask your provider, if they support it, freely or not. We are not reponsable of miuse over system that is not able to make adressing of DNS Root Support, always ask before that an ISP or a DNS provider is able to fill that kind of adresssing and help you resolve most of routine website that you have need privacy or latency (as games).
Failure to have a backbones or server that is misconfigurated could create damage and Kernel Panic most people won’t allow you to reverse IP and don’t forget that even if it’s DNS it will cost money, even, for your ISP that say ‘unlimited’ deal it is still monitored by your ISP.
Some country have limitation over the use of the demo shown. Such as Europe.