A Practical Guide to Fedora™ and Red Hat Enterprise Linux, Fifth Edition

25. iptables: Setting Up a Firewall

In This Chapter

How iptables Works

Rules, matches, targets, and chains

820

Network packet

821

Jumps and targets

822

JumpStart: Building a Firewall Using system-config-firewall

Anatomy of an iptables Command

Building a Set of Rules

system-config-firewall: Generates a Set of Rules

Sharing an Internet Connection Using NAT

The iptables utility builds and manipulates network packet filtering rules in the Linux kernel. You can use iptables to create a firewall that protects a system from malicious users and to set up NAT (Network Address Translation, page 1095), which can allow multiple systems to share a single Internet connection. The iptables utility is flexible and extensible, allowing you to set up both ...