[Mashiro]

@sagher

With no mean of any kind of emergency access to your VPS you will have a hard time accessing the VPS and reverting any kind of changes. There is absolutely nothing you can do in that case in terms of getting the iptables setting reset. Here contacting staff would be necessary and they would do it for you.

So in order to avoid that you have to learn how to use iptables beyond this basic guide. This is just a basic. Keep that in mind. And testing of rules should be done if possible in another similar environment to see how it plays out. Even a small local VM would be enough to test these basic rules in your local LAN. There you have direct console access and can undo changes or flush the whole iptables configuration to delete everything.