In this tutorial, we will explain you how to block and unblock an IPv4 and IPv6
Address on your Linux Dedicated Server with iptables.

Block an IPv4 Address

iptables -A INPUT -s IP_ADDRESS -j DROP

Block an IPv6 Address

ip6tables -A INPUT -s IP_ADDRESS -j DROP

Block an IPv4 Address on a specific port

iptables -A INPUT -s IP_ADDRESS --dport 80 -j DROP

Block an IPv6 Address on a specific port

ip6tables -A INPUT -s IP_ADDRESS --dport 80 -j DROP

Unblock an IPv4 Address

iptables -D INPUT -s IP_ADDRESS -j DROP

Unblock an IPv6 Address

ip6tables -D INPUT -s IP_ADDRESS -j DROP

Remember to save your Firewall rules

service iptables save
service ip6tables save