DOCUMENT:Q142034 14-FEB-2002 [winnt] TITLE :Domain Controllers Unable to Communicate Over IPX Token-Ring WAN PRODUCT :Microsoft Windows NT PROD/VER:3.51 4.0 OPER/SYS: KEYWORDS:kbenv ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Windows NT Server versions 3.51, 4.0 ------------------------------------------------------------------------------- SUMMARY ======= This article helps you configure routed IPX running over Token Ring to properly support communication between Windows NT Server 3.51 domain controllers. This article is specific to ACC Nile Routers with no filtering, running IPX over Token Ring in a non-NetWare environment, although it is likely to be applicable to other routers. It is assumed that the Windows NT 3.51 servers are running only the NWLINK protocol. The problem symptoms are that a Windows NT 3.51 Primary Domain Controller (PDC) cannot communicate over the WAN with one of its Backup Domain Controllers (BDCs) - drives cannot be mapped, browse lists are not correct and the domain cannot be synchronized. MORE INFORMATION ================ - Make sure the routers are NOT filtering any type 20 (Hex 14) WAN broadcast IPX packets on the WAN link. - Make sure NETBIOS is enabled on the routers. - Make sure that the SAP Agent service is running on both the PDC and BDC. - The two DCs may be trying to communicate at a bigger frame size (4096 bytes). The size of these packets going over a WAN link may be slow enough for their connection to time-out. Use regedt32 and add a REG_DWORD value of 576 to RouterMTU. It should be added to: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\NwlnkNb\Parameter This limits the size of the NETBIOS over NWLink IPX packets to 576 bytes. You can fine tune this setting to achieve optimal throughput. The ACC Nile routers have a default value for their maximum transmission unit of 576 bytes. This can be modified using the "Set IPX network MTU" command and can range from 576 bytes to 4491 bytes on Token-Ring networks. - Make sure the IPX net numbers and frame types for the DCs match the network segments on which they are located, especially if you have initially configured and tested them on the same segment before moving the BDC across the WAN link. NetWare is manufactured by Novell, Inc., a vendor independent of Microsoft; we make no warranty, implied or otherwise, regarding this product's performance or reliability. Additional query words: prodnt ====================================================================== Keywords : kbenv Technology : kbWinNTsearch kbWinNT351search kbWinNT400search kbWinNTSsearch kbWinNTS400search kbWinNTS400 kbWinNTS351 kbWinNTS351search Version : 3.51 4.0 ============================================================================= 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.