DOCUMENT:Q166186 09-AUG-2001 [winnt] TITLE :OS/2 with TCP/IP May Refuse Socket Connections from Windows NT PRODUCT :Microsoft Windows NT PROD/VER:winnt:3.51,4.0 OPER/SYS: KEYWORDS:kbnetworkkbbuglist kbfixlist ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Windows NT Workstation versions 3.51, 4.0 - Microsoft Windows NT Server versions 3.51, 4.0 ------------------------------------------------------------------------------- SYMPTOMS ======== Windows NT Workstation clients connecting to an OS/2 Warp server running Lotus Notes may experience a problem where the clients are using all of the available sockets on the OS/2 Warp server. This causes a problem where no new clients are able to attach to the Lotus Notes server because there are no sockets available. Netstat -n shows clients with several connections with a state of FIN-WAIT-2. Traces show that the computer running Windows NT Workstation is not completing the close correctly by ACKing the server Fin. The OS/2 server retries several times and then resets the connection: CLIENT (ack-Fin) ================ 13 0.237 HP D882D6 Cisco 01522C TCP .A...F, len: 0, seq: 960111578- 960111578, ack:2041908096, win: 7826, src: 2130 dst: 1352 Client 144.250.61.21 IP Server(ack) =========== 14 0.239 Cisco 01522C HP D882D6 TCP .A...., len: 0, seq:2041908096- 2041908096, ack: 960111579, win:28672, src: 1352 dst: 2130 144.250.61.21 Client IP Server (ack-Fin) ================ 15 0.244 Cisco 01522C HP D882D6 TCP .A...F, len: 0, seq:2041908096- 2041908096, ack: 960111579, win:28672, src: 1352 dst: 2130 144.250.61.21 Client IP Server (ack-Fin) ================ 19 0.804 Cisco 01522C HP D882D6 TCP .A...F, len: 0, seq:2041908096- 2041908096, ack: 960111579, win:28672, src: 1352 dst: 2130 144.250.61.21 Client IP . . . The server continues to ACK-Fin retry and then resets the connection. Server (reset) ============== 100 319.554 Cisco 01522C HP D882D6 TCP .A.R.., len: 0, seq:2041908097- 2041908097, ack: 960111579, win:28672, src: 1352 dst: 2130 144.250.61.21 Client IP CAUSE ===== There is a problem in Tcpip.sys where the Fin ACK is received from the server and is processed, but it is not acknowledgeed. This problem has been corrected in a new version of Tcpip.sys. STATUS ====== Microsoft has confirmed this to be a problem in Windows NT version 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 Microsoft has confirmed this to be a problem in Windows NT version 3.51. A supported fix is now available, but has not been fully regression-tested and should be applied only to systems experiencing this specific problem. Unless you are severely impacted by this specific problem, Microsoft recommends that you wait for the next Service Pack that contains this fix. Contact Microsoft Technical Support for more information. Additional query words: ====================================================================== Keywords : kbnetwork kbbuglist kbfixlist Technology : kbWinNTsearch kbWinNTWsearch kbWinNTW400 kbWinNTW400search kbWinNT351search kbWinNT400search kbWinNTW351search kbWinNTW351 kbWinNTSsearch kbWinNTS400search kbWinNTS400 kbWinNTS351 kbWinNTS351search Version : winnt:3.51,4.0 Issue type : kbbug ============================================================================= 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.