Testing NIS 2010 firewall

Hi there,I am fairly new to computing & recently installed NIS 2010 & am delighted with the program! A friend,who is a bit of an "expert", has suggested I download a program called Shields Up from a company called GRC.He says I should use this to test the firewall in NIS... I am a bit nervous about doing this. Has anyone used this or a similar program to test the NIS firewall? I must admit that if faults were found,I wouldn't know how to rectify them anyway! Advice needed please...   johnandpatsy

[edit: Clarified subject.]

Message Edited by shannons on 12-19-2009 08:40 PM