Linux Firewalls: Attack Detection and Response with iptables, psad, and fwsnort

This chapter introduced the iptables rule-listing mechanism, Linux port and network daemon information available via netstat, and a few of the third-party tools available for verifying that the firewall rules are installed and working as you expect.

This chapter emphasized the firewall rules and the ports they protect. Chapter 9 shifts the focus away from firewalls and into the broader topic of network and system security.