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Q104296: RRAS Uses Larger MTU Than Other OSPF Routers

Article: Q104296
Product(s): Microsoft Windows NT
Version(s): winnt:4.0
Operating System(s): 
Keyword(s): kbinterop kbnetwork
Last Modified: 08-AUG-2001

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The information in this article applies to:

- Microsoft Windows NT Server version 4.0 
- Microsoft Routing and Remote Access Service Update for Windows NT Server version 4.0 
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SYMPTOMS
--------

Your Routing and Remote Access Service (RRAS) server that is using Open
Shortest Path First (OSPF) is transmitting network packets larger than your
other OSPF routers. Therefore, the other OSPF routers must fragment the
packets coming from your RRAS server.

CAUSE
-----

RRAS sets the maximum transmission unit (MTU) equal to the specified value
in the Advanced properties of the OSPF Configuration dialog box for your
OSPF interface; however, other OSPF routers set the MTU to their specified
value minus the IP header.

STATUS
------

Microsoft has confirmed this to be a problem in Routing and Remote Access
Update for Windows NT Server version 4.0. This problem was corrected in
the Routing & Remote Access Service Hotfix Update. You can obtain this
update from Microsoft's World Wide Web Site on the Internet at the
following location:

http://www.microsoft.com/ntserver/commserv/exec/feature/routing.asp

NOTE: Because the Microsoft Web site is constantly updated, the site
address may change without notice. If this occurs, link to the Microsoft
home page at the following address:

http://www.microsoft.com

Additional query words: routing protocol

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Keywords          : kbinterop kbnetwork 
Technology        : kbWinNTsearch kbWinNT400search kbWinNTSsearch kbWinNTS400search kbWinNTS400 kbAudDeveloper kbRRASNTSearch kbRRASNT400
Version           : winnt:4.0
Issue type        : kbbug

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