Linux 101: Configuring and managing iptables to improve network security
This document describes how important good iptables management is to tight security in a Linux networking environment.
Basics of firewalls
Every new Linux user will at some point start wondering about installing a firewall application on this strange new operating system. Eventually everyone also runs across the concept of iptables. Early on, one might not know what iptables means, or even have heard the term. This is quite a disappointing state of affairs, considering how important good iptables management is to tight security in a Linux networking environment.
I'm going to assume you've heard of a firewall and have some vague notion of what that means in relation to computers and networking. As a quick summation, though, a firewall basically provides and enforces rules for allowing or denying network access on specific ports, from or to specific networked computers, and so on.