Windows NT IP Router Loses Learned Routes

 Last reviewed: December 29, 1997
Article ID: Q177656
The information in this article applies to:
  • Microsoft Windows NT Server version 3.5, 3.51 and 4.0
  • Microsoft Routing and Remote Access Service Update for Windows NT Server version 4.0

SYMPTOMS

Your Windows NT server that is running either Routing Information Protocol (RIP) for IP or Routing and Remote Access Service (RRAS) may lose its routing table after a few minutes. There are no event logs or other messages to indicate a problem.

CAUSE

The other routers with which your Windows NT router is communicating are sending RIP v1 announcements to the "all zeros" subnet of the network instead of the "all ones" subnet.

RESOLUTION

To resolve this issue, you will need to configure your other routers to use an "all ones" broadcast address. Please consult the documentation that came with your routers for information on how to do this.

MORE INFORMATION

Traditionally the broadcast address to which a RIP v1 router sends its routing table is the .255, or "all ones" subnet. With a network number of 191.23.107.0 the broadcast address would be 191.23.107.255, assuming normal subnetting. Some older network operating systems use the .0, or "all zeros," subnet for their broadcasts and those systems broadcast to an address that is identical to the network number. 

Keywords          : NTINTEROP ntnetserv ntrouter NTSrv nttcp kb3rdparty kbinterop kbnetwork
Version           : WinNT:3.5,3.51,4.0
Platform          : winnt
Issue type        : kbprb

================================================================================

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.

Last reviewed: December 29, 1997
© 1998 Microsoft Corporation. All rights reserved. Terms of Use.