NetStumbler is probably the first wireless discovery tool that
people come across. It is free, easy to install and simple to use.
Netstumbler is a tool for Windows that allows you to detect
Wireless Local Area Networks (WLANs) using 802.11b, 802.11a and 802.11g.
Netstumbler sends out a probe request about once a second, and
reports the responses. This is known as Active Scanning.
Once Netstumbler is
installed all you need is a
card then simply double click on the Netstumbler icon and Netstumbler will
start probing for nearby wireless LANS:
One of the weaknesses of
Netstumbler is its inability to detect Wireless LANS utilising hidden SSIDs.
include a very useful graphical representation of signal strength (indicated in
green) and noise ratio (indicated in red) over time, which is extremely useful
for direction finding Wireless LANS:
Netstumbler is able to
merge .ns1 files via the File > Merge option in the menu.
GPS configuration can be
carried out via the View > Options > GPS tab.
The Scan speed can also
be altered via View > Options > General tab.
Netstumbler saves files
in the .ns1 format. Providing a GPS device is attached these files
can then be then be imported (via
Stumbverter) into Microsoft's MapPoint software to produce a graphic
representation of any Wardriving or Site Surveys that may have been carried out: