SNA Server 802.2 Connection Fails to Reactivate

• Microsoft Windows NT 3.51 (SP1-SP5)
• Microsoft Windows NT 4.0 (SP1 and SP2)
• Microsoft SNA Server for Windows NT, versions 2.0, 2.1, 2.11, 3.0

SYMPTOMS

If an SNA Server 802.2 connection (over Token Ring, Ethernet or FDDI) is manually stopped or fails due to an outage, the connection may stop responding (hang) in an incoming or inactive status and cannot be reactivated until the SNA Server service is stopped and restarted. When attempting to restart the connection, the status will remain as incoming or inactive, and will never indicate a pending status.

If multiple connections all share the same 802.2 link service, this problem may only affect a single connection.

This problem can also occur when connecting a branch-based remote link service through an 802.2 distributed link service running on a centralized server, though the behavior within SNA Admin or Manager is different. The remote link service may indicate a pending status when it is restarted.

To confirm this problem using SNA Server tracing, a Level 2 message trace on the 802.2 link service (for example, snadlc1, snadlc2 and so on) is required. This trace will indicate a call to data link control (DLC) close station which never completes.

For information about a problem that has similar symptoms, but a different cause, please see the following article in the Microsoft Knowledge Base:

   ARTICLE-ID: Q147514
   TITLE     : Stopping SNA Server Service Causes Perpetual "Stopping"
               Status

CAUSE

When an 802.2 connection is shut down, the SNA Server link service submits a DLC.CLOSE.STATION request to the Windows NT Dlc.sys driver. If the link station is in a checkpoint state within the Windows NT DLC driver (where the t1 or ti timer has expired for the link station), the DLC.CLOSE.STATION attempt will never complete. Because the link station has not completed the shutdown process, the SNA Server link service is not able to reactivate the connection.

RESOLUTION

A hotfix to Windows NT 3.51 and 4.0 is available to correct this problem. To resolve this problem, obtain the hotfix mentioned below.

STATUS

Microsoft has confirmed this to be a problem in Windows NT 3.51, Windows NT 3.51 (SP1-SP5), and Windows NT 4.0 (SP1, SP2). This problem was corrected in the latest Microsoft Windows NT 4.0 U.S. Service Pack. For information on obtaining the service pack, query on the following word in the Microsoft Knowledge Base (without the spaces):

   S E R V P A C K