There are several aspects to firewalls and the Linux Netfilter subsystem that could not be covered in this chapter. For more information, refer to the following resources.
- The Reference Guide has a comprehensive chapter on
iptables, including definitions for all command options. - The
iptablesman page contains a brief summary of the various options, as well. - A list of common services and their port numbers can be found in Appendix C, Common Ports and in
/etc/services.