Iptables is an extremely flexible firewall utility built for Linux operating systems. Whether you’re a novice Linux geek or a system administrator, there’s probably some way that iptables can be a great use to you. Read on as we show you how to configure the most versatile Linux firewall.
iptables is a command-line firewall utility that uses policy chains to allow or block traffic. When a connection tries to establish itself on your system, iptables looks for a rule in its list to match it to. If it doesn’t find one, it resorts to the default action.
iptables almost always comes pre-installed on any Linux distribution. To update/install it, just retrieve the iptables package:
sudo apt-get install iptables
To put it as simply as possible, SELinux is an access control implementation for the Linux kernel.
As an administrator, you define rules in user space and if the Linux kernel has been compiled with SELinux support, those rules will be adhered to by the kernel.
If we want to disable SELinux we just write [ selinux = disable ]