Multiple Processes Are Able to Open the Same Winsock Port

• Microsoft Windows NT operating system versions 3.51 and 4.0
• Microsoft Windows NT Server versions 3.51 and 4.0

SYMPTOMS

A Winsock application may appear to have stopped responding or it may not be able to send or receive data. All other services and applications, including other Winsock applications, continue to function without problems.

CAUSE

On systems running multiple Winsock applications that request the same specific port, repeated requests for a Winsock port that was in the process of being opened could result in two or more of the processes being assigned the port. The last process assigned would continue to function normally, while the other processes would fail to send or receive data over the port.

RESOLUTION

An updated version of Afd.sys has been created to correct the problem. After applying the fix, the system must be restarted before the change will take effect.

STATUS

Microsoft has confirmed this to be a problem in Windows NT versions 3.51 and 4.0. 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