Using DLC and IPX Protocols May Corrupt Incoming Packets

• Microsoft Windows NT Server version 3.51

SYMPTOMS

When you use DLC and NWLINK protocols on Windows NT Server version 3.51, incoming DLC packets may become corrupted. The problem was observed on a multiprocessor IBM 720 computer with an IBM PCI ETHERNET adapter running Windows NT Server version 3.51 Service Pack 4, SNA Server and SMS 1.1.

CAUSE

In this case, SMS was generating local traffic (sending and receiving frames to itself) using UNC name over NWlink protocol. NWLink depends on the NDIS Wrapper or the NDIS MAC driver to provide loopback functionality. Consequently, frames are sent out on the wire and then received back in. Occasionally, under stress, incoming DLC frames were getting corrupted by the loopback nwlink data frames.

RESOLUTION

To work around this problem, install another protocol (TCP/IP or NetBEUI) using the Control Panel Network tool and make sure that NWLink is not the first protocol to bind to the Workstation service.

STATUS

Microsoft has confirmed this to be a problem in Windows NT version 3.51. We are researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.

Additional query words: ipx

Keywords : kbenv kbinterop kbnetwork ntprotocol kbbug3.51 NTSrv
Version : WinNT:3.51
Platform : winnt
Issue type : kbbug