iplock
Easy to use tool to block unwanted network access.
The iplock tool is a simple iptables extension that allows you to run iptables commands that otherwise require root access in order to block and unblock IP addresses in your firewall.
This is particularly useful if you have a webserver such as Apache2 running a scripting language such as PHP without root permissions. When you detect that a user is likely a hacker (i.e. tries to access a folder named wp-admin on a non-Wordpress website) then you can use iplock <his-IP-address> to block him...