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Firewall-testing tools

I am doing research presently on firewalls, and I was wondering if there is any information you can provide me with on tools for testing the effectiveness of a firewall. Thank you.

There are some pretty good tools to test firewalls, and they are free. You should run Nessus (, a free open source vulnerability scanner, against your firewall to determine if there are any problems with it. Nessus also includes a whole category of vulnerability checks just for firewalls. Additionally, you should look at Firewalk (, a tool for determining packet filter firewall rule sets. You should probably also look at how the firewall handles fragmented packets, using FragRoute ( Finally, ICSA Labs, a division of TruSecure Corp., certifies firewalls. You can get more information about the tests they run their firewalls through.

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This was last published in August 2002

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