Multiprocessor computer may stop responding (hang) because of Tcpip.sys

A multiprocessor computer running Microsoft Windows NT version 4.0 may appear to stop responding (hang) when subjected to heavy TCP/IP stress. The system will continue to respond to PINGs, but higher level TCP/IP activity will be blocked. If other network protocols are installed, the system may continue to function normally except for activities that depend on TCP/IP.

For this problem to occur, a process must have an open handle to an address and an open handle to a connection and must try to close both simultaneously (as, for example, might happen at process termination). Under very specific and timing-dependent situations, Tcpip.sys can become deadlocked, blocking further work by the driver. When this happens, other parts of the system will typically continue running for a period of minutes or longer until higher level services that depend on Tcpip.sys also become blocked, waiting for the driver.

Windows NT 4.0

Service pack information

To resolve this problem, obtain the latest service pack for Microsoft Windows NT 4.0. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

Windows NT Server 4.0, Terminal Server Edition

Windows NT 4.0

Service pack information

This problem was first corrected in Microsoft Windows NT 4.0 Service Pack 5.Microsoft has confirmed that this is a problem in Windows NT 4.0. This problem was first corrected in Windows NT 4.0 Service Pack 4.

Windows NT Server 4.0, Terminal Server Edition

Microsoft has confirmed that this is a problem in Windows NT Server 4.0, Terminal Server Edition.