Tools for Finding Hot Spots

Tools for Finding Hot Spots
When you’re on the road looking for a freenet, a community hotspot, or a
commercial provider, here are a couple of ways that you can get your laptop
or handheld computer to find available networks:
Do your homework: If you know exactly where you’re going to be, you
can do some online sleuthing, find the available networks, and write
down the SSIDs and/or Wired Equivalent Privacy (WEP) passwords (if
required) before you get there. We talk about these in more detail in
Chapter 10. Most hot spots don’t use WEP (it’s too hard for their customers
to figure out), but you’ll find the SSID (and the WEP password, if
applicable), on the Web site of the hot spot provider that you’re planning
on using. Just look in the support or how-to-connect section.
Look for a sign: Those providers that push open hot spots have adopted
a standard logo that should be displayed prominently in a place where
you can log on.
Rely on your network adapter’s client software: Many network adapter
software systems will give you a nice pull-down list of available access
points. In most cases, this won’t really tell you any details about the
access points, but you can do the trial-and-error thing to see whether
you can get online.
Use a network sniffer program: These programs work with your network
adapter to ferret out the access points near you and provide a bit of information
about them. In the next two sections, we describe sniffers from
two companies: Netstumbler.com and Boingo. (Note: In most cases,
network sniffer programs are used to record and decode network packets —
something the highly paid network analysts at your company might use.
In this case, we’re referring to programs that are designed solely for wireless
LANs and which sniff out radio waves and identify available networks.)
We find sniffer programs to be quite handy because they’re a great way to
take a quick survey of our surroundings when we’re on the road. For example,
Pat (one of the authors of this book) was recently staying at a hotel that
belonged to a chain partnered with Wayport, but Wayport hadn’t officially
started offering service yet . . . and the hotel staff was clueless. No problem! A
quick session using the Network Stumbler software (see the next section),
and lo and behold! The Wayport access point in the lobby was up and running,
and with a quick flip of the wallet (to pull out his prepaid card), Pat was
up and running on high-speed wireless Internet. Take that, dialup!
Network sniffer programs are also a good way to help you evaluate the security
of your own network. In fact, that’s the main reason why the developers
of Network Stumbler created the program. After you implement some of the
security steps that we discuss in Chapter 10, you can fire up your favorite
sniffer program and see whether you’ve been successful.
Netstumbler.com
The granddaddy of wireless network sniffer programs is Network Stumbler
(www.netstumbler.com), which is a Windows program (works with Windows
95/98/Me/2000/XP) that connects to the PC Card network adapter in your
laptop and lets you survey the airwaves for available Wi-Fi access points.
Network Stumbler will list all available access points, giving you relatively
detailed information about things such as the SSID and Media Access Control
(MAC) address of the AP, whether WEP is enabled, the relative power of the
signal, and more. You can even combine Network Stumbler with a Global
Positioning System (GPS) card in your laptop to figure out exactly where you
and the access point are located.
Network Stumbler users can upload their surveys to the Netstumbler.com
Web page and contribute to a database of available access points that the
Netstumbler.com folks maintain. You can see a map at www.netstumbler.
com/nation.php to get an idea of places where people have already used the
program. You can submit search queries on this Web page if you want to see
other people’s survey results.
Network Stumbler won’t work with every Wi-Fi card. You can find a list of
compatible cards on the Netstumbler.com Web site.
Figure 16-2 shows Network Stumbler in action in Pat’s house, tracking down
his two access points. (Looks like none of his neighbors are wireless yet!)

Figure 16-2:
Netstumbling
Pat’s
house —
access
points
named after
the dogs!
If you use a Pocket PC handheld computer, the folks at Netstumbler.com have
a program for you: Mini Stumbler, available at the same Web site (www.net
stumbler.com). There’s also a similar program available for Mac OS X computers,
called MacStumbler (www.macstumbler.com).
In fact, a growing number of these network sniffer programs are available,
and most of them free to download. You can find a list at the Personal Telco
Project at www.personaltelco.net/index.cgi/WirelessSniffer.
Boingo
Boingo’s client software (available at www.boingo.com) can also be used as a
network sniffer program (as long as you’re using a compatible operating
system and network adapter). The primary purpose of this software, of
course, is to manage your connections to Boingo’s network, but Boingo has
also designed the software (and encourages the use of it) as a means of finding
and connecting to freenets and other public open networks.
You can even use the Boingo software as a manager for all your Wi-Fi network
connections. If you’ve got a wireless network at home, one or more in the
office, plus some public networks that you want to connect to, try out
Boingo’s software. It’s really pretty cool.