Microsoft KB Archive/931533

= The IAS service stops unexpectedly on a remote RADIUS server that is running Windows Server 2003 =

Article ID: 931533

Article Last Modified on 10/11/2007

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APPLIES TO


 * Microsoft Windows Server 2003, Standard Edition (32-bit x86)
 * Microsoft Windows Server 2003, Enterprise Edition
 * Microsoft Windows Server 2003, Web Edition
 * Microsoft Windows Server 2003, Datacenter Edition (32-bit x86)
 * Microsoft Windows Server 2003, Enterprise Edition for Itanium-based Systems
 * Microsoft Windows Server 2003, Datacenter Edition for Itanium-Based Systems
 * Microsoft Windows Server 2003, Standard x64 Edition
 * Microsoft Windows Server 2003, Enterprise x64 Edition
 * Microsoft Windows Server 2003, Datacenter x64 Edition

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SYMPTOMS
On a Remote Authentication Dial-in User Service (RADIUS) server that is running Microsoft Windows Server 2003, the Internet Authentication Service (IAS) service stops unexpectedly. Then, the following event is logged in the System log: Event Type: Error

Event Source: Service Control Manager

Event Category: None

Event ID: 7034

Description:

The Internet Authentication Service service terminated unexpectedly.

Additionally, the Isasam.log file contains the following information:

State attribute is present, but unrecognized.

This problem occurs if the following conditions are true:
 * An end-user logs on to the client computer by using a user principal name (UPN).
 * The 802.1X settings on the client computer do not match the remote access policy on the RADIUS server. For example, the client computer uses Extensible Authentication Protocol-Transport Layer Security (EAP-TLS) for 802.1X authentication. But the RADIUS server requires Protected EAP (PEAP) for 802.1X authentication.
 * The RADIUS client reuses an outdated State attribute during RADIUS authentication.



CAUSE
This problem occurs because the RADIUS client sends an EAP Identity packet that has the State attribute applied. This State attribute is created for a previous conversation that has already been rejected by the IAS service. Then, the RADIUS client sends a negative acknowledgement (NAK) packet to the RADIUS server. An access violation occurs when the IAS service incorrectly processes the NAK packet.



Hotfix information
A supported hotfix is now available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing this specific problem. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next service pack that contains this hotfix.

To resolve this problem, submit a request to Microsoft Online Customer Services to obtain the hotfix. To submit an online request to obtain the hotfix, visit the following Microsoft Web site:

http://go.microsoft.com/?linkid=6294451

Note If additional issues occur or any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. To create a separate service request, visit the following Microsoft Web site:

http://support.microsoft.com/contactus/?ws=support

Prerequisites
No prerequisites are required.

Restart requirement
You do not have to restart the computer after you apply this hotfix.

Hotfix replacement information
This hotfix does not replace any other hotfixes.

File information
The English version of this hotfix has the file attributes (or later file attributes) that are listed in the following table. The dates and times for these files are listed in Coordinated Universal Time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time item in Control Panel.

Windows Server 2003 with Service Pack 2, x64-based versions


STATUS
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the &quot;Applies to&quot; section.



MORE INFORMATION
For more information, click the following article number to view the article in the Microsoft Knowledge Base:

824684 Description of the standard terminology that is used to describe Microsoft software updates

Additional query words: RADIUS IAS 802.1X crash PEAP EAP TLS

Keywords: kbbug kbfix kbqfe kbpubtypekc kbexpertiseinter kbhotfixserver kbwinserv2003postsp2fix KB931533

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