I have to agree with mcstooge. The best way to protect your network is to footprint it yourself using the same tools the blackhats use. You should have an advantage here, as you already know user accounts, passworts, ip addresses, services, operating systems, etc.
In a previous post, I made a list of tools and informational sites that are indespensable. You can find it here .
Also, check out this post for some system hardening info for Windows,Linux, and UNIX
Sometimes, you just have to beat them at their own game!
"If you know the enemy and know yourself, you need not fear the result of a hundred battles. If you know yourself but not the enemy, for every victory gained you will also suffer a defeat. If you know neither the enemy nor yourself, you will succumb in every battle."
Sun Tsu
The Art of War
