Chapter 7. Using iptables

Proper iptables Syntax

In our experience, some of the problems with iptables that are more difficult to diagnose stem from a lack of proper understanding of iptables usage and syntax. As part of the troubleshooting process, make sure you double-check the proper syntax for iptables commands and that you understand how the commands are supposed to be used.

It is beyond the scope of this book to document all the switches for iptables; however, a few brief pointers should help with uncovering the proper manner in which a command should be executed. The first useful tool is iptables itself. iptables has a certain amount of built-in documentation that can be accessed by passing iptables the -h switch. When combined with module ...

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