I want to stop internet on my system using iptables so what should I do?
iptables -A INPUT -p tcp --sport 80 -j DROP
iptables -A INPUT -p tcp --dport 80 -j DROP ?
Reality is you're asking 2 different questions.
also the internet is not simply the
will block all outbound HTTP requests, going to port 80, so this won't block SSL, 8080 (alt http) or any other weird ports, to do those kinds of things you need L7 filtering with a much deeper packet inspection.