In the following article we will show you how you can secure and protect your Ubuntu or Debian based virtual server using a firewall application, called iptables.
What is iptables?
It is is a user space application program that allows a system administrator to configure the tables provided by the Linux kernel firewall (implemented as different Netfilter modules) and the chains and rules it stores.
In order to keep down the number of attempted break-ins and to filter the ports opened on your virtual server, it is necessary to properly configure your firewall.