Hardware Reference
In-Depth Information
Wireless Network Security
When I was writing the original edition of
Upgrading and Repairing PCs
back in the
1980s, the hackers' favorite way of trying to get into a network without authorization was
discoveringthetelephonenumberofamodemonthenetwork,dialinginwithacomputer,
and guessing the password, as in the movie
War Games
. Today,
war driving
has largely
replaced this pastime as a popular hacker sport. War driving is the popular name for driv-
ing around neighborhoods with a laptop computer equipped with a wireless network card
on the lookout for unsecured networks. They're all too easy to find, and after someone
gets onto your network, all the secrets in your computer can be theirs for the taking.
Because wireless networks can be accessed by anyone within signal range who has a NIC
matching the same IEEE standard of that wireless network, wireless NICs and access
points provide for encryption options. Most access points (even cheaper SOHO models)
also provide the capability to limit connections to the access point by using a list of au-
thorized MAC numbers (each NIC has a unique MAC). It's designed to limit access to
authorized devices only.
Although MAC address filtering can be helpful in stopping bandwidth borrowing by your
neighbors, it cannot stop attacks because the MAC address can easily be “spoofed” or
faked. Consequently, you need to look at other security features included in wireless net-
works, such as encryption.
Caution
In the past, it was thought that the SSID feature provided by the IEEE 802.11 standards was
also a security feature. That's not the case. A Wi-Fi network's SSID is nothing more than a
networknameforthewirelessnetwork,muchthesameasworkgroupsanddomainshavenet-
worknamesthatidentifythem.ThebroadcastingoftheSSIDcanbeturnedoff(whenclients
