Windows NT SP4 May Cause Loss of TCP/IP Connectivity in WLBS Host

• Microsoft Windows NT Server version 4.0 SP4
• Windows NT Load Balancing Service 1.0

SYMPTOMS

When you apply Windows NT 4.0 Service Pack 4 (SP4) to your computer running Windows NT Load Balancing Service (WLBS), the following problems may occur:

• On a WLBS host that consistently experiences heavy loads of traffic, WLBS may stop servicing client requests. Although the cluster can converge, IP connectivity is disrupted.



• The WLBS cluster does not converge. The 'wlbs query' command returns:

  "converging with the following hosts:".

  NOTE: The command should at least display the WLBS cluster converging with itself, even if it was the only host in the cluster.

CAUSE

This problem occurs because Network Driver Interface Specification (NDIS) incorrectly thinks WLBS is out of resources and stops sending WLBS packets to the Media Access Control driver. This behavior occurs because of a WLBS incompatibility with NDIS performance enhancements made in SP4.

RESOLUTION

To resolve this problem, obtain the latest service pack for Windows NT 4.0 or the individual software update. For information on obtaining the latest service pack, please go to:

• http://www.microsoft.com/Windows/ServicePacks/


-or-


• Q152734 How to Obtain the Latest Windows NT 4.0 Service Pack

http://www.microsoft.com/support/supportnet/overview/overview.asp

STATUS

Microsoft has confirmed this to be a problem in the Microsoft products listed at the beginning of this article. This problem was first corrected in Windows NT 4.0 Service Pack 6.

MORE INFORMATION

For more information on the NDIS changes in SP4, please see the following articles in the Microsoft Knowledge Base:

Q217305 Full Duplex Support with Windows NT and Q214455 Ndis Intermediate Driver Model

Additional query words:

Keywords : kbbug4.00 kbfix4.00
Version : winnt:1.0,4.0 SP4
Platform : winnt
Issue type : kbbug