Microsoft KB Archive/264632

= DLC Session Hangs When Using DLSW =

PSS ID Number: 264632

Article Last Modified on 10/16/2002

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The information in this article applies to:


 * Microsoft Windows NT Server 4.0
 * Microsoft Windows NT Workstation 4.0

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This article was previously published under Q264632



SYMPTOMS
You may experience session disconnects under heavy network load when you are using Cisco routers with Data-Link Switching (DLSW) activated.



CAUSE
When an error condition occurs on the network, the stations attempt to reconnect. When you are using DLSW, the Windows NT Data Link Control (DLC) stack may enter an invalid state from which it cannot recover. If you are using a Network Monitor trace, the problem is visible when the client's DLC stack sends &quot;I&quot; frames although it should be in a disconnected state.



RESOLUTION
A supported fix is now available from Microsoft, but it is only intended to correct the problem that is described in this article. Apply it only to computers that are experiencing this specific problem. This fix may receive additional testing. Therefore, if you are not severely affected by this problem, Microsoft recommends that you wait for the next Windows NT 4.0 service pack that contains this fix.

To resolve this problem immediately, contact Microsoft Product Support Services to obtain the fix. For a complete list of Microsoft Product Support Services phone numbers and information about support costs, visit the following Microsoft Web site:

http://support.microsoft.com/default.aspx?scid=fh;EN-US;CNTACTMS

NOTE: In special cases, charges that are ordinarily incurred for support calls may be canceled if a Microsoft Support Professional determines that a specific update will resolve your problem. The typical support costs will apply to additional support questions and issues that do not qualify for the specific update in question.

The English version of this fix should have the following file attributes or later:   Date      Time      Size     File name  Platform 07/12/2000 05:06p  102,512  Dlc.sys    Alpha 07/12/2000 05:08p   55,376  Dlc.sys    Intel



WORKAROUND
If local &quot;acks&quot; (DLC spoofing) are disabled on the routers, this problem does not occur.



STATUS
Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article.

Keywords: kbbug kbQFE KB264632

Technology: kbWinNT400search kbWinNTS400 kbWinNTS400search kbWinNTsearch kbWinNTSsearch kbWinNTW400 kbWinNTW400search kbWinNTWsearch

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