Microsoft KB Archive/314994

= You Cannot Receive DHCP Configuration After Successful Authentication =

Article ID: 314994

Article Last Modified on 9/26/2005

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APPLIES TO


 * Microsoft Windows XP Professional

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This article was previously published under Q314994



SYMPTOMS
After you successfully connect to a domain controller by using an Extensible Authentication Protocol over LAN (EAPOL)/802.1x connection, you may not be able to receive Dynamic Host Configuration Protocol (DHCP) settings from the DHCP server.



CAUSE
This behavior can occur because the 802.1x driver processes TCP/IP packets asynchronously. However, the EAPOL-Key packets must be processed synchronously. If the EAPOL-Key packets are processed out of order, they are discarded. As a result, even if authentication with the domain controller succeeds, you may not be able to receive DHCP configuration settings.



RESOLUTION
To resolve this problem, obtain the latest service pack for Windows XP. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

322389 How to Obtain the Latest Windows XP Service Pack

The English-language version of this fix should have the following file attributes or later:   Date         Time   Version      Size     File name 20-Dec-2001 18:13  5.1.2600.26  184,320  Wzcsvc.dll



STATUS
Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article. This problem was first corrected in Windows XP Service Pack 1.



MORE INFORMATION
This Windows XP update modifies the 802.1x driver so that it processes each received packet before it reads the next one. This ensures that when client authentication succeeds, the EAPOL-Key packets are correctly introduced to the driver.

Keywords: kbbug kbfix kbqfe kbnetwork kbwinxpsp1fix kbhotfixserver KB314994

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