DOCUMENT:Q135700 08-AUG-2001 [winnt] TITLE :Modifications to NETBT.SYS to Support Layered Drivers PRODUCT :Microsoft Windows NT PROD/VER:winnt:3.51 OPER/SYS: KEYWORDS:kbnetwork ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Windows NT Workstation version 3.51 - Microsoft Windows NT Server version 3.51 ------------------------------------------------------------------------------- SYMPTOMS ======== Under Windows NT, when a device driver creates an I/O Request Packet (IRP) to pass to an underlying driver, it creates the IRP with a fixed number of I/O stack locations, one for each driver in the chain of layered drivers for which the request is bound. Each stack location contains the parameters, function codes, and context used by the corresponding driver to determine what it is supposed to be doing with the request. In Windows NT 3.51, I/O Request Packets built by the NETBT.SYS driver always have a stack frame size of 1. This presents a problem should device driver developers wish to "layer" an additional driver between NETBT.SYS and TCPIP.SYS because there are not enough stack frames in the IRP for the vertical driver to use. For certain operations, NetBT also incorrectly passes IRPs directly to TCP/IP, thereby skipping any intermediate drivers in the driver chain. RESOLUTION ========== To resolve this problem, install the fix mentioned below. To correct this problem, apply the fix mentioned below. STATUS ====== Microsoft has confirmed this to be a problem in Windows NT version 3.51. This problem was corrected in the latest U.S. Service Pack for Windows NT Workstation or Server version 3.51. For information on obtaining this update, query on the following word in the Microsoft Knowledge Base (without the spaces): S E R V P A C K Additional query words: prodnt irp stack frame ====================================================================== Keywords : kbnetwork Technology : kbWinNTsearch kbWinNTWsearch kbWinNT351search kbWinNTW351search kbWinNTW351 kbWinNTSsearch kbWinNTS351 kbWinNTS351search Version : winnt:3.51 ============================================================================= THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY. Copyright Microsoft Corporation 2001.