Network Storm Caused By Basic Redirector

• Microsoft Network Client version 3.0 for MS-DOS
• Microsoft Workgroup Add-On for MS-DOS version 3.11

SYMPTOMS

Your network workstation configured with the Basic Redirector from the Microsoft Network Client version 3.0 for MS-DOS, or from the Microsoft Workgroup Add-On for MS-DOS version 3.11 may hang and create a network storm (excessive network traffic that can render a network ineffective). This problem will only occur with some applications in specific situations.

CAUSE

When an application requests a read past the end of a file on a network server, the server will respond with an indication that there is no data in the requested range. The redirector then adjusts the request, based on the current size of the file on the server.

In the case of an empty (zero-byte) file, there is an error in the adjustment code of the Basic Redirector which causes the it to repeatedly make the same network request. The sequence of network requests are a Seek, followed by a Read, then another Seek and Read, and another, and so on.

Some commercial applications can, in some circumstances, initiate this sequence of requests, triggering the network "storm".

WORKAROUND

Use the Full Redirector, the redirector from Lan Manager version 2.2, or Windows for Workgroups version 3.11.

STATUS