There are many software applications that can be used for war driving. The most popular scanning software can be downloaded from the Web for free. You will need to pick a software package that works with your laptop or PDA. Also you should consider other factors, such as setup, support, and results output. For example, for casual, easy war driving, NetStumbler works great. For more extreme war driving and network scanning, Kismet is good choice. Also, there are several commercial (for pay) products on the market that can be used.

When choosing war driving software, interoperability becomes a major factor in your success of getting the system to work. Most of the scanning software out there requires certain types of network adapters to function properly. In fact, some software requires a very specific type of adapter before it will even detect the adapter.

Research the software you wish to use, and compare it to the wireless adapters available to you. Remember that your operating system will also factor in to what works together.We will focus mainly on Microsoft Windows XP, but software is available for just about every OS on the market, including open sources like Linux.

Kismet is a passive wireless scanner in the sense that it does not broadcast and request packets of information from the networks being scanned. It is like a radio receiver tuned to Wi-Fi signals. Kismet features an ever-increasing list of network recording functions. For a complete list, visit the Documentation section on the Kismet Wireless Web site. Some notable features of Kismet include:

Kismet detects hidden, or cloaked, SSIDs first by detecting the generic signal from the access point. Then it watches for a wireless client to connect to the AP. When the client connects, it reveals the associated SSID.

Kismet can and will sniff and record all wireless traffic that passes through it. Encrypted data packets will appear as garbage and will be much harder, or impossible, to decode and view. Unencrypted data is totally vulnerable to interception. If a network is unencrypted, Kismet can watch everything happening without a second glance. Always encrypt your wireless traffic.

One of the most interesting facets of war driving is being able to plot your discoveries on a street map. This brings a remarkable visual aspect to your efforts. The results of a war drive are instantly recognizable, and you can make these maps over time to see how Wi-Fi is growing in your area.

You will need a Global Positioning System (GPS) receiver to feed location information to the laptop.We will cover this topic in greater detail in Chapter 6, “War Driving with NetStumbler,” but for now you will want to know a little bit to get your car set up to have a GPS satellite track your location.

The Global Positioning System is made up of a “constellation” of 24 satellites circling the Earth. These satellites are continuously beaming a location signal Earthward. A GPS receiver uses the exact time and location of the satellite to precisely determine your location anywhere on the globe. The accuracy of your location information is directly related to the quality of your GPS equipment. The term GPS is generally used interchangeably to refer to either satellites or receiver.

As one would expect, GPS receivers come in many forms. The most common are the handheld, dash-mounted, and dedicated receivers, which are illustrated in Figure 5-7. The most popular form for in-car use is either the handheld or dash-mounted receiver. Recently, dedicated computer-use-only receivers have become available. These dedicated receivers connect directly to your laptop or PDA and require the computer to power and display data. Although you can’t take a dedicated GPS with you on the trail, they work great for war driving!

Universal serial bus (USB) connectors have come to replace the old 9-pin serial ports in most laptops these days. Dedicated GPS receivers often use USB to connect with the laptop. The GPS hardware ships with software drivers that enable the GPS and power it up when inserted into the USB port. Follow the instructions included with the GPS software to get it working with your computer.

Many newer cars come with a built-in GPS navigation system. Having this on hand is great for finding your way around town. But they generally don’t have the outputs needed to interface with a laptop. Extensive hardware hacking is usually necessary to get a navigation system configured for war driving.

War driving software needs to interface with the GPS via a serial COM port on your operating system. This COM port can be a physical port, like a 9-pin connector on the back of your computer connected to COM 1. Or it can be a virtually mapped port. Virtual port mapping is necessary when using a USB or Bluetooth GPS receiver. It’s also necessary if you are using a Serial-to-USB converter as would be needed on a laptop without a 9-pin serial interface.

Some of the newer PDAs and GPS receivers have built-in Bluetooth connectivity. You can configure the GPS and the PDA to communicate using Bluetooth with a virtual serial port. Set the Bluetooth serial interface to emulate a COM port, such as COM 5. And set the WD software to listen on COM 5.

The war driving software must be configured to listen on the port to which the physical or virtual port is set. In addition, make sure your GPS and software is configured to communicate using the same GPS protocol such as the industry-standard 4,800 baud protocol, “NMEA 0183.”

With so many GPS receivers in the market, you may need to fool your OS to mimic a visible serial port. The type of GPS will determine the interface available for your computer. Finally, the GPS communication protocol needs to be compatible with the war driving software. Most GPS units have a selectable output. Just make sure it’s set to the same protocol on both ends.