From the course: Linux Tips

Unlock this course with a free trial

Join today to access over 22,400 courses taught by industry experts.

Understanding iptables

Understanding iptables - Linux Tutorial

From the course: Linux Tips

Understanding iptables

- [Instructor] Iptables is packet-filtering software that makes use of Linux's net filter system in order to process and dispatch network traffic coming into and going out of a system. In this episode, I want to introduce you to writing and changing rules within Iptables, so the process doesn't look as mysterious as it can seem. Iptables rules make up what are called chains, primarily, the input, output, and forward chains. You can create other chains as well, and rules in these chains can refer traffic to chains. So writing firewall rules is really a little bit like programming with conditional statements. You can effectively say, if something matches this set of parameters, do this. Otherwise, go over here. Ultimately, a packet will be acted upon in one of two ways. If it matches a rule, and that rule acts to accept or reject the packet, then that action is taken. And if the packet doesn't match any rule, then the chain's default action is taken. The chains of rules that Iptables…

Contents