Datagram Sends Fail if Route is Not in IPX Cache

• Microsoft Windows NT Workstation version 3.51
• Microsoft Windows NT Server version 3.51

SYMPTOM

If your transport driver interface (TDI) program is a client of the IPX protocol and uses datagram-sends for connectionless sends at an interval that is greater than 15 minutes, it fails. If the interval is shorter than 15 minutes, your TDI client performance is slowed down.

This symptom occurs if your TDI client program is a socket program using datagram-sends, the NetWare redirector, or the Server Message Block (SMB) redirector or server.

The problem does not occur with the SPX or NetBEUI protocol, or their TDI clients. The RIP protocol is also not affected by this problem.

CAUSE

When your transport driver interface (TDI) client does a send to a destination whose route is not in the IPX cache, IPX sends a corrupted packet in form of some superfluous bytes appended to the IPX header. The next time the client sends the datagram, assuming it is within 15 minutes which is the default routing information protocol (RIP) time-out, it succeeds. If a send happens after 15 minutes, then assuming that the route did not get cached again, the send fails. A subsequent send succeeds. This pattern repeats itself with each datagram send in these intervals.

RESOLUTION

To correct this problem, install the latest U.S. Service Pack for Windows NT version 3.51.

STATUS

Microsoft has confirmed this to be a problem in Windows NT version 3.51. This problem has been corrected in the latest U.S. Service Pack for Windows NT version 3.51. 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