Ipt_fw is a firewall for Linux based on iptables. It is designed for client systems. Ipt_fw outputs a shell script containing iptables commands, so inspection of the settings it creates is easy. The configuration files are made in LibreOffice（OpenOffice）Calc. Making of the firewall and a machine using the firewall are separated. It allows you to set the user level and features detailed logging, IP address blacklist management, and iptables integrity.
Spampig DnsblCheck takes the IP address of a mail server and looks it up in common blacklists and whitelists. The program tests against the major block lists from Spamhaus, SORBS, Spamcop, Barracuda, UCEProtect, and others. In addition to blacklists, it also checks against IP address and domain name whitelists and even checks PTR record integrity. The program returns results quickly, typically in less than a few seconds. If you don't get results quickly, it indicates you may have DNS problems and knowing this can also be useful. This application can be useful to spam fighters and email users who are struggling to find out why their messages are being blocked.