The Cable Guy - August 2004

Wireless LAN Enhancements in Windows XP Service Pack 2

By The Cable Guy

Microsoft Windows XP Service Pack 2 (SP2) includes a number of enhancements to support Institute of Electrical and Electronic Engineers (IEEE) 802.11-based wireless local area networks (LANs). These enhancements include the following:

• Built-in support for Wi-Fi Protected Access (WPA)

  Originally provided for Windows XP as a free download (the WPA Wireless Security Update in Windows XP), Windows XP SP2 includes WPA support. If your wireless network adapter and its driver support WPA, you can configure WPA authentication and encryption options from the properties of a wireless network. For more information, see "Changes to the Network Connections Folder" in this article. For more information about WPA, see Wi-Fi Protected Access (WPA) Overview, the March 2003 Cable Guy article.

• Wireless Provisioning Services (WPS)

  WPS is a set of wireless client extensions that allow for a consistent and automated configuration process when connecting to public wireless hotspots that provide access to the Internet or to private organization wireless networks that provide guest access to the Internet. For more information, see Wireless Provisioning Services Overview, the December 2003 Cable Guy article.

• Wireless Network Setup Wizard

  The Wireless Network Setup Wizard steps you through the configuration of wireless network settings and then writes that configuration to a Universal Serial Bus (USB) flash drive, which you can then use to configure other wireless devices. For more information, see The New Wireless Network Setup Wizard in Windows XP Service Pack 2, the June 2004 Cable Guy article.

• Wireless Zero Configuration service logging

  Windows XP supports detailed logging for various components to troubleshoot the wireless authentication process. You can enable logging for specific components or for all components by using the netsh ras set tracing command. Windows XP now includes tracing for the Wireless Zero Configuration service, which is responsible for detecting and attempting to connect to preferred wireless networks. To see the Wireless Zero Configuration service logs, type netsh ras set tracing * enabled at a command prompt to enable logging for all components. Disable and then enable your wireless network connection in the Network Connections folder. Then, view the Wzcdlg.log and Wzctrace.log files in the %SystemRoot%\Tracing folder. To disable tracing for all components, type netsh ras set tracing * disabled at a command prompt.

• New Repair functionality for wireless connections

  The Repair capability has been enhanced in Windows XP SP2 for wireless connections. You can access the Repair capability through the Repair context menu option of a connection or from the Repair button on the Support tab of the Status dialog box of a connection. When you repair a wireless connection, it is disabled and re-enabled, which clears many error conditions on wireless network adapters.

• Changes to default 802.1X authentication behavior

  To prevent possible issues with 802.1X authentication being enabled and then automatically disconnecting the wireless client when the 802.1X authentication process fails, Windows XP SP2 now automatically disables 802.1X authentication on the Authentication tab of the properties of a wireless network when you manually configure an encryption key.

• New Wireless Network Connection dialog box

  The Wireless Network Connection dialog box has been greatly enhanced to indicate much more than just the wireless network name, also known as the Service Set Identifier (SSID), and the type of wireless network (infrastructure vs. ad-hoc). For more information, see the "New Wireless Network Connection Dialog Box" section in this article.

• Changes to wireless connection and wireless network properties in the Network Connections folder

  Many enhancements have been made to the properties of a wireless connection and to the properties of a wireless network in the Network Connections folder. For more information, see "Changes to the Network Connections Folder" in this article.

• Changes to wireless connection process and status reporting

  To make the wireless connection state more meaningful and to better inform you of the capabilities of the connection, the reporting of the status of the wireless connection process has been enhanced. For more information, see "Improvements in Reporting the Status of a Wireless Connection" in this article.

New Wireless Network Connection Dialog Box

The new Wireless Network Connection dialog box, previously known as the Connect to Wireless Network dialog box in Windows XP (prior to Service Pack 1 [SP1]) and the wireless network adapter dialog box in Windows XP SP1, presents you with a list of wireless networks that have been detected, allowing you to select a wireless network connection by name and attempt to connect to it.

The following figure shows the new Wireless Network Connection dialog box.

If your browser does not support inline frames, click here to view on a separate page.

In Windows XP (prior to SP2), the previous dialog boxes only displayed the name of the network and whether it was an infrastructure mode or ad hoc mode network.

The new Wireless Network Connection dialog box in Windows XP SP2 displays the following for each detected wireless network:

• The type of wireless network

  An antenna icon indicates an infrastructure mode wireless network. The icon with two wireless client computers indicates an ad hoc mode wireless network. An icon for the logo of a wireless Internet service provider indicates that the wireless network uses WPS to automate and secure registration.

• The wireless network name

• The wireless network signal strength

  This was previously only available from the General tab of the status of the wireless connection after connecting to a wireless network.

• Whether the wireless network has security enabled (the lock icon and the "Security-enabled wireless network" label)

• The status of the wireless network to which the wireless client is connected (the "Connected" label)

• Whether the wireless network is a preferred network (the star icon)

From the Wireless Network Connection dialog box, you can also do the following:

• Perform another scan of wireless networks within range by clicking the Refresh network list network task
• Start the Wireless Network Setup Wizard by clicking the Set up a wireless network for a home or small office network task
• Display the Wireless Networks tab of the wireless connection to change the order of preferred networks and perform other advanced configuration settings by clicking the Change the order of preferred networks related task
• Display the properties of the wireless connection by clicking the Change advanced settings related task

Changes to the Network Connections Folder

Changes to dialog boxes for a wireless connection in the Network Connections folder include the following:

• Updated Wireless Networks tab for the properties of wireless network adapter
• Updated Association tab for the properties of a wireless network
• New Connection tab for the properties of a wireless network
• Updated wireless connection status dialog box

Updated Wireless Networks tab for the properties of a wireless connection

The following figure shows the updated Wireless Networks tab for the properties of a wireless connection in the Network Connections folder.

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On the Wireless Networks tab, the list of available networks has been replaced with the View Wireless Networks button, which displays the new Wireless Network Connection dialog box when clicked.

Updated Association tab for the properties of a wireless network

The following figure shows the updated Association tab for the properties of a wireless network.

If your browser does not support inline frames, click here to view on a separate page.

This new tab is the same as the Association tab for the WPA Wireless Security Update in Windows XP, in which the Wireless network key (WEP) section is now named Wireless network key and the Data encryption (WEP enabled) and Network Authentication (Shared mode) check boxes are replaced with drop-down boxes.

The Data encryption (WEP enabled) check box has been replaced with a Data encryption drop-down box that provides the following selections:

• Disabled Disable encryption of 802.11 frames.
• WEP Use 802.11 Wired Equivalent Privacy (WEP) for encryption.
• TKIP Use WPA Temporal Key Integrity Protocol (TKIP) for encryption. This selection is only available if the wireless network adapter and its driver support WPA.
• AES Use Advanced Encryption Standard (AES) for encryption. This selection is only available if the wireless network adapter and its driver support WPA and the optional AES encryption algorithm.

The Network Authentication (Shared mode) check box has been replaced with a Network Authentication drop-down box that provides the following selections:

• Open Use the open system authentication method.
• Shared Use the shared key authentication method using the shared key authentication key that is typed in Network key and Confirm network key.
• WPA Use WPA authentication (802.1X) with an EAP type configured on the Authentication tab.
• WPA-PSK Use WPA authentication (802.1X) with a pre-shared key that is typed in Network key and Confirm network key.

The WPA and WPA-PSK options are only available if the wireless network adapter and its driver support WPA.

For more information about 802.11 authentication and encryption, see IEEE 802.11 Wireless LAN Security with Microsoft Windows XP.

New Connection tab for the properties of a wireless network

The following figure shows the new Connection tab for the properties of a wireless network.

If your browser does not support inline frames, click here to view on a separate page.

The Connect when this network is within range checkbox specifies whether you want the wireless client to automatically connect to this network when it is in range (the default setting) or you want to connect to this network on demand, by double-clicking on it from the Wireless Network Connection dialog box.

Updated wireless connection status dialog box

The Status dialog box for a wireless connection has been modified to show the name of the wireless network to which the connection is connected and provides a button to display the Wireless Network Connection dialog box.

The following figure shows the new wireless network adapter Status dialog box.

If your browser does not support inline frames, click here to view on a separate page.

Improvements in Reporting the Status of a Wireless Connection

When a wireless client running Windows XP SP2 attempts a wireless connection, it goes through the following authentication states, which are indicated in the Wireless Network Connection dialog box, as the status of the wireless connection in the Network Connections folder, and in the new wireless connection Status dialog box:

• Validating identity

  Credentials are required for connecting to the wireless network.

• Attempting to authenticate

  Credentials are being exchanged with the wireless network to authenticate a wireless connection.

• Authentication did not succeed

  The credentials for connecting to the wireless network were not valid and authentication has failed.

• Connected

  The credentials for connecting to the wireless network are valid.

Once authentication has succeeded, a wireless client running Windows XP SP2 then attempts to obtain a valid IP address configuration and goes through the following states, which are indicated in the Wireless Network Connection dialog box, as the status of the wireless connection in the Network Connections folder, and in the new wireless connection Status dialog box:

• Acquiring network address

  An IP address configuration is being obtained using the Dynamic Host Configuration Protocol (DHCP).

• Limited or no connectivity

  A DHCP server was not contacted and an Automatic Private IP Addressing (APIPA) address from the range 169.254.0.0/16 was assigned. This state is not shown for wireless ad-hoc networks, which typically do not have DHCP servers. Instead, the status of the connection is displayed as ?Connected.

• Connected

  A DHCP server was contacted and a valid IP address configuration was obtained.

These improvements give the user and the network troubleshooter more information about how the wireless connection is progressing, from the initial association to the allocation of a valid IP address.

If the wireless connection obtains an APIPA address, Windows XP SP2 warns you with the following message in the notification area of the desktop: "The connection has limited or no connectivity. You might not be able to access the Internet or some network resources. For more information, click this message." When you click on the message, Windows XP displays the Support tab of the Status dialog box for the wireless connection, from which you can view additional details or attempt to repair the connection.

Additionally, the wireless connection icon in the notification area has been updated to have a slightly different look than other networking icons. Windows XP SP2 shows the connection in the following states:

• Disconnected The normal wireless connection icon is displayed with an overlaid red "X".
• Connecting (authenticating and obtaining an IP address) The normal wireless connection icon is displayed with an animated amber ball moving back and forth.
• Warning (APIPA address configuration) The normal wireless connection icon is displayed with an overlaid yellow yield symbol.
• Connected (authenticated and valid IP address obtained) The normal wireless connection icon is now animated, showing when traffic is sent or received.

For More Information

For more information about wireless support in Windows XP SP2, consult the following resources:

• IEEE 802.11b Wireless Networking Overview
• The New Wireless Network Setup Wizard in Windows XP Service Pack 2
• Wireless Provisioning Services Overview
• Wi-Fi Protected Access (WPA) Overview
• Windows XP Service Pack 2: Resources for IT Professionals

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