How do I bypass Windows Firewall to scan IP addresses?
To perform a network security test, I'm using an IP scanner to check on IP addresses. However, some of my users use the Microsoft Firewall, which, in turn, hides their IP addresses. Is there a way that will allow me to scan their IP addresses?
I assume you're talking about a port scanning regimen in which you are using some sort of automated tool that pegs each machine on a given network or subnet or a subset of network addresses thereof to determine what services are running based on which ports respond to the network security test. It's true that the Microsoft Firewall, properly configured, will put the machine into a stealth mode, which hides most of the surface area of a machine from attack. This is a good thing. It's what you want.
If you want a more definitive result, I suggest using an old machine and a downloaded copy of Linux (it's freely available, as you may know) and then use the Nmap program to perform an in-depth IP scan. As long as you identify the range of IP addresses you're looking for, Nmap can provide a reasonably definitive answer to your question of which machines are advertising services to the general Internet public.
This was first published in July 2007