Open Source Security Tools : Practical Guide to Security Applications part 36. Few frontline system administrators can afford to spend all day worrying about security. But in this age of widespread virus infections, worms, and digital attacks, no one can afford to neglect network defenses. Written with the harried IT manager in mind, Open Source Security Tools is a practical, hands-on introduction to open source security tools. | Page 329 Friday June 25 2004 12 07 AM Performing a Wireless Network Security Assessment 329 NetStumbler Options Under the View menu select the Options submenu to display the dialog box for setting NetStumbler options. Table lists the tabs and the choices available. Tips for Effective and Ethical Wireless Auditing Get Permission Make sure you have permission from management to do your wireless assessment. If you are an outside consultant you should have a letter of permission or engagement signed by upper management. If the company does not own the building get management to clear it with building security so you have permission to be on the premises. Determine Your Wireless Perimeter Walk the entire perimeter and find out how far your signal goes. A good rule of thumb is to go only in publicly accessible places that wireless crackers or war drivers would have access to. If possible get a map and mark your wireless perimeter on it. Table NetStumbler Options Tabs Descriptions General Set the rate of polling for your access points. You can also set it to auto-adjust based on your speed if using GPS. There is an option to automatically reconfigure your card when a new network is found but you probably don t want to do this in a busy area if there are a lot of access points around your card will be changing configuration every few seconds and it will slow your computer down. Also the software may end up configuring your card for a foreign network and you could be trespassing inadvertently. Not cool See the sidebar on Tips for Effective and Ethical Wireless Auditing . GPS Set up your GPS receiver to interface with NetStumbler. I used a Meridian handheld GPS with a serial cable. All I had to do was set the right port and communication settings and NetStumbler started importing the data right away. Scripting Set up to call external scripts. You can use Visual Basic or any number of Windowsbased languages to do additional things based on the .