DOCUMENT:Q162054 10-AUG-2001 [winnt] TITLE :RouterMTU Registry Value Is No Longer Supported PRODUCT :Microsoft Windows NT PROD/VER:WINNT:3.1 3.5 3.51 4.0 OPER/SYS: KEYWORDS:kbnetwork ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Windows NT Server version 3.1 - Microsoft Windows NT Workstation version 3.1 - Microsoft Windows NT Advanced Server, version 3.1 - Microsoft Windows NT Workstation versions 3.5, 3.51, 4.0 - Microsoft Windows NT Server versions 3.5, 3.51, 4.0 ------------------------------------------------------------------------------- SUMMARY ======= The Windows NT 3.5 Resource Kit documentation was not updated properly from version 3.1, and lists a number of invalid TCP/IP registry parameters. The parameters listed in this article should be used in their place. The Windows NT 3.5 TCP/IP stack was changed significantly from version 3.1, so many of the old parameters are no longer valid. The Windows NT 3.51 Resource Kit should include the necessary corrections. MORE INFORMATION ================ Page 586 of Appendix B in "Optimizing Windows NT" from the Windows NT Resource Kit version 3.5 describes the RouterMTU registry parameter. RouterMTU functionality was replaced in Windows NT 3.5 by PMTU Discovery, as defined in RFC 1191. For additional information on the usage of the RouterMTU parameter in Windows NT 3.1, see the following article in the Microsoft Knowledge Base: ARTICLE-ID: Q102973 TITLE : REG: TCP/IP Transport Entries, PART 1 For additional information on PMTU Discovery, see the following article in the Microsoft Knowledge Base: ARTICLE-ID: Q159211 TITLE : Diagnoses and Treatment of Black Hole Routers Additional query words: mtu size prodnt request comment comments ====================================================================== Keywords : kbnetwork Technology : kbWinNTsearch kbWinNTWsearch kbWinNTW400 kbWinNTW400search kbWinNT351search kbWinNT350search kbWinNT400search kbWinNTW350 kbWinNTW350search kbWinNTW351search kbWinNTW351 kbWinNTW310 kbWinNTSsearch kbWinNTS400search kbWinNTS400 kbWinNTS351 kbWinNTS350 kbWinNTS310 kbWinNTAdvSerSearch kbWinNTAdvServ310 kbWinNTS351search kbWinNTS350search kbWinNTS310search kbWinNT310Search kbWinNTW310Search Version : WINNT:3.1 3.5 3.51 4.0 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.