MCSA/MCSE Self-Paced Training Kit (Exam 70-270): Installing ...

15-36 Chapter 15 Configuring Network and Internet Connections
■ The random IV is only 24 bits and is reused. On large networks, APs and stations
reuse the IV pretty frequently (even as often as every hour). Many programs exist
that can capture network traffic and examine the details of the data packets being
transmitted, including details about the IV.
Wi-Fi Protected Access
To help address the security limitations of WEP, a group of wireless equipment known
as the Wi-Fi Alliance developed a new encryption standard named Wi-Fi Protected
Access (WPA). WPA builds upon the security in WEP in two main ways:
■ WPA provides stronger data encryption. WPA uses Temporal Key Integrity Protocol
(TKIP), a protocol that provides per-packet key mixing, a message integrity
check, and a stronger IV with keys that are not reused for longer periods of time.
■ WPA requires 802.1x authentication to ensure that only authorized users or computers
are allowed to connect to a wireless network. 802.1x authentication is
optional with WEP.
Configuring Wireless Networking in Windows XP Professional
Windows XP Professional includes a feature called Zero Client Configuration that eases
the detection of and connection to wireless networks, and also makes transitions from
one wireless network to another more transparent to users. Windows XP Professional
supports both ad-hoc and infrastructure wireless networking, and also supports both
WEP and WPA encryption.
Note When Windows XP Professional first shipped, it did not include support for WPA. Support
was provided later via the Windows WPA Client Update, available at http://support.microsoft
.com/Default.aspx?kbid=815485. However, WPA support is also included with Windows XP
Service Pack 2 without needing to use this client update.
How to Connect to a Wireless Network
After installing a wireless network adapter, Windows XP Professional attempts to locate
wireless networks in the area automatically. When Windows locates a network, it displays
an icon in the notification area (a picture of a computer with wireless “waves”
coming out of it). Windows also displays a ScreenTip (a pop-up notification balloon)
above that icon, letting you know that it has detected wireless networks.
To connect to a wireless network, use these steps:
1. Right-click the wireless connection icon in the notification area, and then click
View Available Wireless Networks.