Firewall Tester 1.0 review

by on

The Firewall Tester (FTester) is a tool designed for testing firewalls filtering policies and Intrusion Detection System (IDS) capabi

License: GPL (GNU General Public License)
File size: 30K
Developer: Andrea Barisani
0 stars award from

The Firewall Tester (FTester) is a tool designed for testing firewalls filtering policies and Intrusion Detection System (IDS) capabilities.The tool consists of two perl scripts, a packet injector (ftest) and the listening sniffer (ftestd). The first script injects custom packets, defined in ftest.conf, with a signature in the data part while the sniffer listens for such marked packets. The scripts both write a log file which is in the same form for both scripts. A diff of the two produced files (ftest.log and ftestd.log) shows the packets that were unable to reach the sniffer due to filtering rules if these two scripts are ran on hosts placed on two different sides of a firewall. Stateful inspection firewalls are handled with the 'connection spoofing' option. A script called freport is also available for automatically write to log files.

Of course this is not an automated process, ftest.conf must be crafted for every different situation. Examples and rules are included in the attached configuration file.

The IDS (Intrusion Detection System) testing feature can be used either with ftest only or with the additional support of ftestd for handling stateful inspection IDS, ftest can also use common IDS evasion techniques. Instead of using the configuration syntax currently the script can also process snort rule definition file.

These two scripts were written because I was tired of doing this by hand (with packet-crafting tools and tcpdump), I know that there are at least two dozens of other methods to do this but another reason was to learn some perl ;). I hope that you enjoy them.

Here are some key features of "FirewallTester":
firewall testing
IDS testing
simulation of real tcp connections for stateful inspection firewalls and IDS
connection spoofing
IP fragmentation / TCP segmentation
IDS evasion techniques

The following perl modules are required: Net::RawIP, Net::PcapUtils, NetPacket

What's New in This Release:
added marker feature for running multiple ftest/ftestd instances
configuration directives lookup is now anchored properly
fixed IP ID field logging bug when max value is reached

Firewall Tester 1.0 keywords