Windows for Workgroups Client Session Dropped (114221)

SYMPTOMS

A session between a Windows for Workgroups 3.11 client and a Windows NT Advanced Server over IPX with NetBIOS protocol may be dropped. Several problems may occur with Windows for Workgroups clients when this happens, including experiencing a general protection (GP) fault, or receiving an Server Message Block (SMB) error 1,6 indicating an Invalid File Handle during file I/O after the session has been idle for three or four minutes.

This problem usually occurs when Windows for Workgroups clients are running applications of the Windows NT Advanced Server and have several files open on the server. Net Sessions on the Windows NT Advanced Server displays the active sessions on the server; if the session remains idle for a few minutes, the session is dropped and when you attempt any operation related to the open files, you may experience a GP fault.

CAUSE

The network sessions get dropped because the Windows for Workgroups client does not respond to the keep-alive packets from the server if they are sent at 30-second intervals, which is the default of NWNBLINK.

WORKAROUND

To work around this problem, change the KeepAliveTimeout value in the Windows NT Advanced Server Registry from 60 (this value represents half- seconds) to 30. The Registry entry for KeepAliveTimeout is in the following location:

   LocalMachine\System\CurrentControlSet\Services\NWNBLINK\Parameters

When you change the KeepAliveTimeout value to 30, the keep-alive packets are sent every 15 seconds. This helps maintain the session and eliminates GP faults.

STATUS

Microsoft has confirmed this to be a problem. We are researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.