RRAS Uses Larger MTU Than Other OSPF Routers

This article was previously published under Q104296

SYMPTOMS

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

CAUSE

This behavior occurs because the RRAS server 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 without the IP header.

STATUS

Microsoft has confirmed that this is a problem in Routing and Remote Access Update for Windows NT Server version 4.0.
This problem was corrected in the Routing and Remote Access Service Hotfix Update.
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