DOCUMENT:Q186357 10-AUG-2001 [winnt] TITLE :RPC UseWinsockForIP Is Only Applicable to UDP and IPX PRODUCT :Microsoft Windows NT PROD/VER:WinNT:4.0 OPER/SYS: KEYWORDS:kbFEA kbWinNT400sp4fix kbWinNT400sp4fea ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Windows NT Server versions 4.0 SP2, 4.0 SP3 - Microsoft Windows NT Workstation versions 4.0 SP2, 4.0 SP3 - Microsoft Windows NT Server, Enterprise Edition version 4.0 - Microsoft Windows NT Server version 4.0, Terminal Server Edition ------------------------------------------------------------------------------- IMPORTANT: This article contains information about editing the registry. Before you edit the registry, make sure you understand how to restore it if a problem occurs. For information about how to do this, view the "Restoring the Registry" Help topic in Regedit.exe or the "Restoring a Registry Key" Help topic in Regedt32.exe. SYMPTOMS ======== Winsock Proxy lets a Windows Sockets application, running on a private network client, behave as if it were directly connected to a remote Internet server application when, in fact, the Microsoft Proxy Server is the host for this connection. This means that all application-level communications are channeled through a single secured computer -- the gateway computer running Microsoft Proxy Server. Ordinarily, for datagram packet transfers, the RPC transport DLL bypasses the sendto( ) and recvfrom( ) functions provided in Wsock32.dll, and communicates directly with the underlying device driver. This improves the speed of packet transfers but makes Winsock Proxy features unavailable to the application. Effective with Windows NT 4.0 with Service Pack 2, the RPC transport checks the registry to see whether to use the function calls provided in Wsock32.dll or to talk directly with the device driver. NOTE: To use RPC with Winsock Proxy, you must add the following information to the registry: WARNING: Using Registry Editor incorrectly can cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk. For information about how to edit the registry, view the "Changing Keys And Values" Help topic in Registry Editor (Regedit.exe) or the "Add and Delete Information in the Registry" and "Edit Registry Data" Help topics in Regedt32.exe. Note that you should back up the registry before you edit it. HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Rpc\UseWinsockForIP REG_DWORD "1" CAUSE ===== RPC on Windows NT uses optimization for connection oriented traffic. This optimization includes calling the TDI transport. As a result, RPC bypasses the Winsock proxy. RESOLUTION ========== To resolve this problem, obtain the latest service pack for Windows NT 4.0 or Windows NT Server 4.0, Terminal Server Edition. For additional information, please see the following article in the Microsoft Knowledge Base: Q152734 How to Obtain the Latest Windows NT 4.0 Service Pack After you obtain the latest service pack, perform the following steps: WARNING: Using Registry Editor incorrectly can cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk. For information about how to edit the registry, view the "Changing Keys And Values" Help topic in Registry Editor (Regedit.exe) or the "Add and Delete Information in the Registry" and "Edit Registry Data" Help topics in Regedt32.exe. Note that you should back up the registry before you edit it. 1. Apply Windows NT 4.0 Service Pack 4. NOTE: The third-party application must also be a Winsock 2.1 LSP (layered service provider). 2. Copy the %SystemRoot%\System32\Rpcltscm.dll file to another name (for example, Rpclts13.dll). 3. For the protocol that is being implemented by the LSP (for example, TCP/IP), replace the reference to Rpcltscm.dll in the registry with the above name. For example, change: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Rpc\ServerProtocols \ncacn_ip_tcp=rpcltscm.dll to: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Rpc\ServerProtocols \ncacn_ip_tcp=rpclts13.dll 4. Shut down and restart your computer. STATUS ====== Microsoft has confirmed this to be a problem in Windows NT 4.0 and Windows NT Server 4.0, Terminal Server Edition. This problem was first corrected in Windows NT 4.0 Service Pack 4.0 and Windows NT Server 4.0, Terminal Server Edition Service Pack 4. ====================================================================== Keywords : kbFEA kbWinNT400sp4fix kbWinNT400sp4fea Technology : kbWinNTsearch kbWinNTWsearch kbWinNTW400search kbWinNT400search kbWinNTW400sp3 kbWinNTW400sp2 kbWinNTSsearch kbWinNTSEntSearch kbWinNTSEnt400 kbWinNTS400sp3 kbWinNTS400sp2 kbWinNTS400search kbNTTermServ400 kbNTTermServSearch Version : WinNT:4.0 Hardware : ALPHA x86 Issue type : kbinfo ============================================================================= 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.