DOCUMENT:Q126652 13-FEB-2002 [winnt] TITLE :FDDI MAC Address Issue with Windows NT 3.5 PRODUCT :Microsoft Windows NT PROD/VER::3.5 OPER/SYS: KEYWORDS: ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Windows NT Workstation version 3.5 - Microsoft Windows NT Server version 3.5 ------------------------------------------------------------------------------- SYMPTOMS ======== Unlike the Ethernet standard, FDDI and TokenRing are capable of using non-canonical or canonical formatting for the MAC Address. If the MAC address for a FDDI node is 800000000000 through FFFFFFFFFFFF, and TCP/IP is being used as the transport protocol, you lose connectivity. CAUSE ===== Windows NT reads the MAC addresses in canonical format and does not properly translate the most significant bit (MSB). In FDDI and TR, if the node address is 0x020406080A0C, then 0x20406080A0C0 goes out on the wire. The bit the should be checked is 0x01 instead of 0x80, for the most significant bit (for directed vs. multicast). STATUS ------ Microsoft has confirmed this to be a problem in Windows NT version 3.5. This problem has been corrected in the latest U.S. Service Pack for Windows NT version 3.5. 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 Additional query words: 3.50 prodnt token ring ====================================================================== Keywords : Technology : kbWinNTsearch kbWinNTWsearch kbWinNT350search kbWinNTW350 kbWinNTW350search kbWinNTSsearch kbWinNTS350 kbWinNTS350search Version : :3.5 ============================================================================= 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 2002.