Howto block IP address with iptables and simple usage.

Command examples
Block IP using iptables simply use the following command by replacing the appropriate IP in the below command :

iptables -I INPUT -s 212.56.88.143 -j DROP

If you wish to unblock any IP then the same command can be used as below :

iptables -I INPUT -s 212.56.88.143 -j ACCEPT

To delete all iptables rules :

iptables -F

To list all iptables rules :

iptables -L -n