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Southern California.

Powering Your Rig
Longevity requires power. If you want to run for more than a few hours, the car™s energy will
have to be tapped. Here are a few tools you can use to extend the uptime of your rig:

DC Power Supply ” Most laptops have accessories for the in-car cigarette lighter or air-
plane power port. Handheld GPS units have two-in-one power and serial cables.
DC-to-AC Inverter ” The mainstay of flexible installations. This converts DC car
power to 110 VAC used by laptops, cell phone chargers, TVs, DVD players, and so on.
Lighter power splitter ” Few cars these days have more than one or two power ports
available. Turn one port into three and power all of your DC devices at once.

Figure 5-12 shows all of these items working in harmony. As you can see, cable management
becomes an issue. Passengers can ride in back!
When using a DC-to-AC power inverter, be sure the inverter has ample wattage for your lap-
top™s input. Look at the power requirements of your laptop. (This is usually on a sticker on the
bottom of the laptop, or on the AC power brick.) Look for DC Output.
Use the formula Power Volts Amperes. For example, if your laptop needs 15 V and draws
4 A, you will need an inverter capable of at least 60 W (15 4 60). See Table 5-2 for actual
power requirements of some popular laptops.
The downside of using a higher wattage inverter is more drain on your vehicle electrical system
and fan noise. The upside is that you won™t tax the inverter causing heat and possible circuit
overload. We prefer inverters of at least double the power than needed.
118 Part II ” War Driving

Table 5-2 Power Consumption on Various Models
Model Volts Amperes Power Requirements (Watts)

Dell Inspiron 20 3.5 70
Compaq Presario 19 3.16 60.04
Sony Vaio 19.5 5.13 100.035

FIGURE 5-12: DC adapter, DC-to-AC inverter, three-way splitter. This rig can run forever.

Installing the System in Your Car
Now is the time to install everything into the car. All of the above items will be gathered
together and quickly installed. When the ideal configuration is achieved, more permanent
mounting options can be explored. For now, let™s just make it safe and easy (and flexible).
The installation is relatively quick and easy. It can be done in six simple steps:
1. Make sure that the wireless card is properly installed.
2. Position the laptop in an ideal place.
3. Attach the rooftop antenna.
4. Add the Global Positioning System.
Chapter 5 ” Gearing Up for War Driving

5. Plug it all in.
6. Launch the software.

Each of these steps is discussed in detail in the paragraphs that follow.

Step 1: Installing the Wireless Card
The laptop should have the wireless card already installed and verified to be working with the
war driving software. If you have a glitch, it™s better to troubleshoot it where you can reach the
keyboard without straining.

Chapter 1 covered the essential but delicate wireless pigtail. The pigtail and the connector to
which it is mated are physically the most fragile components in a war driving setup. It™s easier and
safer to attach pigtail cables before the laptop is securely strapped down. Also, bring extra pig-
tails on your war drives in case of connector breakdown.

Step 2: Placing the Laptop
The ideal position for the laptop is within arms™ reach but not obstructing your view. When
doing a temporary mounting option, you can ensure that the laptop doesn™t slide by using the
seatbelt on the passenger seat. Figure 5-13 shows this setup. Remember to treat cables nicely.
Don™t bend RF cables too tightly and don™t put strain on the connectors.

FIGURE 5-13: Laptop placed securely on the passenger seat.
120 Part II ” War Driving

Step 3: Attaching the Rooftop Antenna
This is where a magnet mount antenna comes in so handy. Place the antenna as close to the
center of the roof as possible while staying away from any roof racks or other antenna.
Run the cable using the least damaging method to get to the interior of the car. You can leave a
window down, but that™s far from ideal. If the cabling is of sufficient strength, you can get away
with closing it in a doorway without much loss. LMR-400 is very good and can take minor
pinching without too much damage.
Figure 5-14 shows a typical magnet mount antenna placed on a roof. Notice how the antenna
is placed well away from the roof rack and the cable comes down through the doorway.

Use care in placing and removing the magnet mount antenna. To avoid damage, pull from the
base, not the cable or aerial. Also, try to pull directly up to avoid scratch marks.

Step 4: Adding the GPS
The GPS receiver needs a clear view of most of the sky. Nowadays, receivers are pretty good at
obtaining a signal without seeing the entire sky. The front or rear window of the car usually has

FIGURE 5-14: Magnet mount antenna placement with cable running through doorway.
Chapter 5 ” Gearing Up for War Driving

FIGURE 5-15: The dashboard makes a nice home for this USB GPS.

enough view to maintain a decent signal. If you have problems getting a location lock, try repo-
sitioning the GPS. Or try a magnet mount external GPS.
Temporary, but functional, placement of a USB GPS is shown in Figure 5-15. Note the simple
suction cup cable management.

GPS receivers have many options. Review all of the options to ensure the GPS is configured cor-
rectly. In particular, make sure it™s not set in a demo or simulation mode.

Step 5: Plugging It All In
All these different components need unique power sources. Let™s look at how to hook them all
together. Figure 5-16 shows the setup all plugged in and ready.
1. The laptop uses its own AC power supply plugged in to a power inverter, which itself is
plugged in to a cigarette lighter.
2. The USB GPS pulls power from the laptop. Alternatively, a DC power source is avail-
able for most GPS receivers.
3. Extra ports are available for the myriad of portable components used while driving.
122 Part II ” War Driving

FIGURE 5-16: Everything is ready to go!

If you are just experimenting, battery power is fine. Laptops and GPS units have batteries. But
the radio in your wireless adapter pulls a lot of juice from your laptop. Expect shortened run-

Step 6: Launching the Software
Now that your equipment is up and running, go ahead and launch the war driving software. It™s
best to do this near a known access point to verify that the software is working.
Ensure that your software is set to reconfigure the adapter on-the-fly. This can be a channel
hopper, as used in Kismet, or a “reconfigure automatically” option, as used in NetStumbler.

War driving software has been known to glitch where it stops detecting new networks. If you
have two known access points, this makes a good test before getting too far down the road.

Finally, make sure the software is receiving GPS data. If you just powered up, the status will say
something like “acquiring” or “locating.” When your position is acquired, the status should
show your actual latitude and longitude coordinates.
Chapter 5 ” Gearing Up for War Driving

Your First War Drive!
Everything is ready. It™s time to get on the road. Start small at first. Drive up and down your street
to see how far away your home network is visible. Then start driving around the neighborhood.
You will be tempted to watch the screen while driving. This habit is very dangerous and definitely
not recommended. Close the lid on your laptop to avoid distraction. Make sure the power man-
agement option is set up for Always On operation so the laptop doesn™t go to sleep.

The laptop does all of the work for you. There is no reason to avert your eyes from the road
while driving. Always pay attention to the road. If something happens on the system, find a safe
place and stop before trying to use the laptop. Don™t let a computer crash turn into a car crash.

Disconnect cables that may get in your way before entering and exiting the car at pit stops.
Cables have a way of finding human appendages. One frantic exit at the Quick Stop can pull
cables loose, never to connect again.

Discovering the Invisible
You will be surprised where wireless networks appear. And you will be even more surprised
when the names people have chosen for their network SSID comes across your screen. Be pre-
pared for the humorous, laughable, obscene, and bizarre.
A remarkable number of access points are using the default configuration. Many people buy an
AP and just plug it in. Since most APs are designed to work out of the box, people just leave
them at the minimum configuration.
The results of your war driving will reveal apparent default configurations. Compare what you
find with the SSIDs listed in Table 5-3. If the SSID is the default, it™s a good chance the owner
just plugged in the new AP and left it that way.
The message boards on have many threads on the SSIDs, war drivers have
discovered. This is by far the most interesting social aspect revealed by war driving.

While war driving, you will discover that about 30 percent of the networks recorded have WEP
Encryption enabled. This 30/70 “rule” has been evident since the earliest war driving results were
posted online. A default SSID that is not WEP-enabled is almost surely a default configuration.

Where to Go? Anywhere!
There is no set rule of where to find the best locations. Since wireless networks are used every-
where, the best locations are, well, everywhere!
Here are some simple tips to help keep you on your way:
1. Set up an audio trigger that announces when new access points are detected.
2. Run the antenna cable through the trunk. Trunks open and close less often than doors.
124 Part II ” War Driving

Table 5-3 Factory Default SSIDs
Manufacturer SSID

Belkin WLAN
Cisco tsunami
Linksys linksys
Microsoft MSHOME
Orinoco WaveLAN Network
Symbol 101

3. Bring extra pigtails in case of breakage.
4. Auto-save the log files every few minutes.
5. When driving at night, switch the color scheme to high-contrast black background.
6. Above all, drive carefully!

A huge number of networks are “wide open,” meaning you could jump onto the network and
surf the Web, check e-mail, or access computers on that WLAN. This tactic is ill-advised and
probably illegal. Even if the “door is open,” it may still be considered a crime to use a network
without permission.

Be sure to get permission from the network owner before trying to use any resources on that
network, including the Internet. Disable the TCP/IP interface on your computer to avoid acci-
dentally associating with a network.
Although few laws or court cases approach the subject, war driving is generally considered law-
ful (by non-lawyer war drivers) since it does not intrude upon network resources or cause mon-
etary loss. The fuzzy gray line of legality appears when resources are tapped. However, there are
actions that are certainly illegal. Be a good neighbor and look but don™t touch.

This chapter has introduced the enlightening and entertaining hobby of war driving. With the
basics covered here, you should be ready to choose a Wi-Fi adapter, war driving software, GPS,
and antenna to install into a car and be ready to go on a war drive.
Chapter 5 ” Gearing Up for War Driving

There are plenty of options available depending on the equipment you have handy, but the
essence is clear. Load some software and take a drive. This is such a new phenomenon that you
will be one of the few who have first-hand access to wireless usage in your neighborhood. Not
only that, it™s fun to go on a drive and see the invisible wireless waves.
Read on to Chapter 6, “War Driving with NetStumbler”, for an in-depth look at NetStumbler
in action. NetStumbler is more than a war driving software. Learn about its easy-to-use
features and interface in the next chapter.
War Driving with
etStumbler is by far the most popular wireless network scanning
utility around, partly because of its extreme capabilities, partly
because it was one of the earliest programs available, partly because
of its ease of use, but mostly because it™s free.
NetStumbler was designed for war driving, so many of its basic features are
in this chapter
well suited to network discovery and logging. NetStumbler connects
to your wireless card and gathers driver-level details from the card.
Installing and
NetStumbler will also interface with a GPS unit to log the location infor-
mation along with the access point (AP) details. This is the essence of war
driving: scanning, discovery, logging, and eventually mapping your results.
When you go beyond the basic war driving functions, you™ll find that
NetStumbler is also a capable network analysis tool. It certainly lacks the
NetStumbler and
power of dedicated network analysis software, but the signal graphing
and multiple access point tracking makes it very functional in some
Using the
NetStumbler is one of the basic tools for war driving. Your next question is
most likely, why war drive? And the short answer is because it™s fun! Once
you start war driving, you will see and learn more about wireless networks
than you thought possible. Using NetStumbler is an art in itself, and
expanding into the subtleties of its operation and abilities will bring you a
deeper understanding of wireless networking in general. NetStumbler files
It™s hard to determine a specific purpose of war driving, and yet, you could
say that it helps one learn more about wireless in its own way. There are so
many aspects to war driving that it will take some time to learn what is
most interesting to you. This chapter will prepare you to go out and
discover some networks with NetStumbler. Chapter 7 will show you how
to plot them on a map. As you delve into this new hobby, you will find new
and interesting ways to work with and visualize wireless networks.
In this chapter, you will learn how to install NetStumbler, read the data
files, and use it to scan for wireless networks. You will also learn about
using NetStumbler for activities other than war driving. After reading this
chapter, you will be able to use NetStumbler like a professional.
128 Part II ” War Driving

Here are the items you will need for this chapter™s project:

1. Laptop computer
2. Wireless adapter compatible with NetStumbler and your version of Windows
3. NetStumbler software”free download
4. GPS receiver to save location information for mapping later (optional)

Installing NetStumbler
Your first and foremost task is to get a copy of NetStumbler working on your computer.
There are many compatibility issues in the world of wireless, and NetStumbler is no exception.
It will help to have a few different Wi-Fi adapter cards on hand. Multiple Windows versions
are supported from Windows 98 on up.
The core NetStumbler executable is quite small, weighing in at less than 500K. But don™t let
the size fool you. Huge features are crammed into that small space.

NetStumbler is beta software and support is limited. It may not work without some experimen-
tation on your part. There are online user forums and FAQ lists available. Still, plan for a bit of
trial and error before finding an equipment combination that works for you.
For Macintosh computers, try Kismac or MacStumbler. Both of these programs are designed for war
driving. Kismac has more network scanning functions and is similar to Kismet for Linux. MacStumbler
is almost a direct clone of NetStumbler. Linux computers have many options available for war driving.

Step 1: Downloading NetStumbler
NetStumbler is a free download. To get it, surf and click on the
“Downloads” link. (You can also download it from the author™s site at

NetStumbler is deemed by the author as “BeggarWare.” The software is supported only by
donations directly to the author, Marius Milner. For license and donation details, see the Help ➪
About ➪ License dialog after you install the software.

There are two different versions of “stumbler,” called NetStumbler and MiniStumbler.
NetStumbler is the full application, which runs on Windows 98, ME, 2000, and XP.
MiniStumbler is like NetStumbler™s little cousin. MiniStumbler runs on handheld PDA plat-
forms running Microsoft Pocket PC 2002 or 2003. Both applications can be used for war driv-
ing, but there are user interface limitations on MiniStumbler.
MiniStumbler is a very good, highly portable wireless network discovery platform. It™s easy to
mount in a car or backpack. If you plan to run MiniStumbler, you should also install
NetStumbler on a computer to work with the files directly. MiniStumbler output files are
directly compatible with NetStumbler, so import and export is not an issue.
Chapter 6 ” War Driving with NetStumbler

The Downloads page will show you the most recent versions of NetStumbler and
MiniStumbler. There is also a link for older versions, and third-party software. Download the
latest version and try that with your system. If you find problems later, you can uninstall it and
try an older version. To download the file, simply click the filename in the Download section.
Save the file to your Windows Desktop.
Since you are here, you should note that the home page is a great news outlet
for all that is happening in the wireless world. And the Forums section is the online hangout
for NetStumbler users. The forums have been active since the first release of NetStumbler (over
2 years). So it™s a wealth of information, and practically the sum total of all knowledge on
NetStumbler. Before posting technical questions to the forums, forum etiquette requires that
you use the search function to see if the topic has been answered before.

Step 2: Installing
To install the newer versions of NetStumbler, launch the file that you just downloaded. The
installation is automatic. Just click Next at the prompts to start the process.
The earliest versions of NetStumbler did not have an installation program. The executable was
downloaded in a Zip file. For this version, you must copy the Netstumbler.exe file to a folder
on your hard disk.
The setup screen for NetStumbler version 0.3.30, shown in Figure 6-1, is quick and easy. Click
the installation options if you would like to change anything. For this chapter, we will assume a
complete install with all options selected.

FIGURE 6-1: NetStumbler setup options. Notice the actual product title,
“Network Stumbler.”
130 Part II ” War Driving

NetStumbler is continuously being revised. At the time of this writing, version 0.4 has not been
released. Expect similarities to previous versions with greater compatibility and user interface
enhancements, including the setup program.

Step 3: Launching for the First Time
To run NetStumbler, click on the shortcut on your desktop. The software will launch to the

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