Err Msg: The Browser Has Received an Illegal Datagram...

• Microsoft Windows NT operating system version 3.1
• Microsoft Windows NT Advanced Server version 3.1

SYMPTOMS

The following error message appears in Event Viewer:

   Error 8006. DGRcvr. The browser has received an illegal datagram from
   the remote computer <computer name> to name <domain name> on transport
   Streams\NBT. The data is the datagram.

CAUSE

This problem is caused by Microsoft LAN Manager 2.2b TCP/IP hub/node service, or by other datagrams on the network, when they are rejected and not processed by Windows NT.

Datagrams are rejected by Windows NT after they cross a TCP/IP hub/node configuration because the node service incorrectly puts data into a reserved byte after the Server Message Block (SMB) Setup Word Count field. This byte is usually 0x00. When the datagram is rebroadcast, the new broadcast contains the illegal data in the reserved byte. Because the byte is reserved, LAN Manager stations don't validate it and accept the byte without error.

Windows NT systems on the subnet generate the above error message when they receive this frame because the SMB Setup Word Count field is validated as a short, even though it is defined as a byte. Usually, the reserved byte is 0x00, so the check passes, but with the extra byte added by the TCP/IP hub/node service, the check fails.

STATUS

Microsoft has confirmed this to be a problem in Windows NT and Windows NT Advanced Server version 3.1. This problem has been corrected in the latest U.S. Service Pack for Windows NT and Windows NT Advanced Server version 3.1. For information on obtaining the Service Pack, query on the following word in the Microsoft Knowledge Base (without the spaces):

   S E R V P A C K