Configuring NetStumbler

There are several ways to customize and configure NetStumbler. Some of them are visual, like fonts and zoom level. Others change scanning options. Feel free to adjust these settings to find out more.

Here is a quick overview of the menus in NetStumbler and some of the important menu items:

File menu: This menu controls file management (except auto-save). You can open, close, and save files from this menu. Also, the Merge command takes two native NetStumbler files and merges them into one. Merge is helpful for making a single file with all of your findings. The file menu also contains the Export function, which is used to export data files for use in other programs like StumbVerter, Excel, and Mapping software.

Edit menu: This menu contains the Delete item command, which you can use to delete access points from the list.

View menu: This menu lists the common Windows commands to change the view, and also has the Fonts and Options commands. Adjusting the fonts setting will change the entire display. If you like large, easy to read fonts, this is where you should make changes.

The options command opens the Options dialog with several settings. More on the options dialog in a bit.

 

Device menu: This menu lets you manually select which wireless adapter NetStumbler will use. If you have one adapter, NetStumbler should decide automatically. Otherwise, you can force NetStumbler to attempt to use any of the recognized adapters in your computer.

Windows: This menu lets you adjust window panes. Set cascading windows or stack them on top of each other. NetStumbler can run several windows at once. It may help to have different windows open with different contents in each window.

Help: There is currently not a help file included with NetStumbler, so the “Help Topics” option will generate an error. The Help About will show version information. And the Help License selection will display the license agreement and extra contact information.

NetStumbler is not well-documented, so trial and error is often the best way to learn exactly what each option does, and some options are self-explanatory.

There are of course some differences in the features between the different NetStumbler versions available. The options panel directly reflects these differences. As an overview, we’ll cover the basic Options panel for NetStumbler 0.3.30. Figure 6-4 shows the General Options panel.

The options are plentiful on the General tab:

Scan Speed determines the rate at which data is captured and updated. Faster speeds create larger data files.

Auto adjust using GPS connects the scan speed to the GPS velocity measurement. Faster vehicle speed increases Scan Speed.

New document starts scanning will begin scanning when NetStumbler is started, or when a new “document” is created.

Reconfigure card automatically sets the Wi-Fi card parameters for war driving.Turn this off when you want to use a network that NetStumbler found.


 

Query APs for names sends additional requests to the discovered network for the “Name” field. Name is completely separate from the SSID.

Save files automatically saves the log file every few minutes. NetStumbler 0.3.30 was the first version to include this option. Use with caution: it can overwrite existing files of the same name.

The GPS tab is used to configure communication options for the GPS receiver. (See the next section.) The Scripting tab is for enabling third-party Visual Basic scripts. The MIDI tab is used in direct connection with signal strength monitoring. Enable MIDI output of SNR ties the signal-to-noise ratio to a MIDI register. A higher pitch means a higher SNR. This is a handy feature for tracking down an AP without watching the screen.

Setting Up a GPS

NetStumbler will record GPS position with all of the other data gathered during scanning. All you need is a GPS reciever with a plug for your laptop. NetStumbler has a few requirements to

 

use a GPS. Most off-the-shelf GPS receivers support these requirements, but it’s a good idea to check the manual:

Must have serial compatibility using a physical port or emulated through software.

Must support one of the four GPS communications protocols:

 NMEA 0183 (preferred)

 Garmin Binary

 Garmin Text

 Tripmate

NetStumbler only recognizes serial data. Serial compatibility is common on handheld GPS receivers. But the GPS receivers with USB interfaces require special interface drivers for Windows. More on configuring a USB to Serial converter is available in Chapter 5.

In addition, NetStumbler supoprts a few different methods of communicating to the GPS receiver as shown in the list above. Make sure your GPS reciever is set to output its data in the same protocol that NetStumbler is configured to receive.

GPS settings are adjusted using the GPS tab in the NetStumbler options panel (as shown in Figure 6-5).


GPS works great using a low serial port speed; 4,800 bits per second is the NetStumbler default. This data rate works fine for almost any application. If your GPS receiver requires a different setting, make changes as necessary.

When you plug in a GPS receiver, make sure that NetStumbler is configured to listen on the same serial port in the GPS Options dialog box.NetStumbler will report GPS status in the bottom right corner of the window. See Table 6-1 earlier in this chapter for a list of common status messages.

After attaching the GPS to the laptop, and configuring NetStumbler, you may need to restart NetStumbler to refresh the GPS port. If the port is unavailable, try using a different serial port. If the port times out, check the cable connections and make sure your GPS is set up to use a serial output with the correct protocol.

If all is set properly, you should see a status message from the GPS right away. “GPS Acquiring” is the most common initial message. That means the GPS is looking for satellites and attempting to resolve its position.

When the GPS is operating correctly, NetStumbler will show the current latitude and longitude in the status message box. Now, every time NetStumbler records information about a wireless access point, it will also record the latitude and longitude reported by the GPS.