8003 browsing errors with UDP forwarding

The following error messages are added to the domain controller's System log (as seen with the Event Viewer) approximately every 12 minutes: Event log information

Routers on your network are configured to forward UDP broadcasts.

If a Windows domain spans more than one subnet and the TCP/IP protocol (NetBT) is used, each subnet will have a Master Browser. If a Master Browser receives server announcements from another computer, claiming to be a Master Browser, an election is forced to ensure that there is only one Master Browser per subnet. These browser elections cause the 8003 message to be recorded.

If the routers on the network are configured to forward UDP broadcasts to UDP ports 137 and 138, then the election broadcasts that are intended to remain in the subnet are forwarded to other subnets.

This has also been seen with bridges or switches between two dissimilar network segments within the same subnet.

To stop the 8003 error messages, make sure the routers on the network are not forwarding UDP broadcasts, keeping browser elections on NetBT local to each subnet and enable WINS or lmhosts on the network for netbios name resolution.

Note Switches that are configured for VLAN's (virtual segmentation) have to be configured on a per VLAN basis to prevent UDP broadcast propagation.

For more information, click the following article number to view the article in the Microsoft Knowledge Base: You can use the Browstat command prompt utility to investigate browsing errors. For more information about browser errors, click the following article number to view the article in the Microsoft Knowledge Base: