This article was previously published under Q273727
This article has been archived. It is offered "as is" and will no longer be updated.
Your computer may stop responding (hang) when the following conditions are true:
The Microsoft IPX/SPX protocol is installed on your computer.
Your computer receives the IPX/SPX NMPI port denial of service.
You are connected to a network that routes IPX packets.
This problem can occur if your computer receives a denial of service that targets an IPX NetBIOS name management port. This type of denial of service can generate large amounts of network traffic (a network storm) by using the IPX/SPX protocol.
A portion of the IPX/SPX protocol that listens on the NMPI port 551h replies to any requesting network address. The NMPI listener software does not filter the requesting computer's network address correctly, and may reply to a network broadcast address, which causes other IPX NMPI listener programs to also reply. This can generate a large amount of unnecessary network traffic.
A supported fix is now available from Microsoft, but it is only intended to correct the problem that is described in this article. Apply it only to computers that are experiencing this specific problem.
To resolve this problem, contact Microsoft Product Support Services to obtain the fix. For a complete list of Microsoft Product Support Services phone numbers and information about support costs, visit the following Microsoft Web site:
NOTE: In special cases, charges that are ordinarily incurred for support calls may be canceled if a Microsoft Support Professional determines that a specific update will resolve your problem. The usual support costs will apply to additional support questions and issues that do not qualify for the specific update in question.
The English version of this fix should have the following file attributes or later:
Date Time Version Size File name Operating system----------------------------------------------------------------------12/08/2000 09:30pm 4.00.958 51,052 Nwlink.vxd Windows 9502/01/2001 05:03pm 4.00.956 108,264 Vserver.vxd Windows 9512/08/2000 09:36pm 4.00.1117 51,567 Nwlink.vxd Windows 95 OSR201/09/2001 01:40pm 4.00.1114 112,904 Vserver.vxd Windows 95 OSR211/28/2000 08:10pm 4.10.2002 51,546 Nwlink.vxd Windows 9801/04/2001 10:30pm 4.10.2002 112,912 Vserver.vxd Windows 9811/28/2000 07:38pm 4.10.2226 51,551 Nwlink.vxd Windows 98 Second Edition01/04/2001 10:32pm 4.10.2225 112,912 Vserver.vxd Windows 98 Second Edition11/28/2000 11:10pm 4.90.3003 51,535 Nwlink.vxd Windows Me01/04/2001 10:06pm 4.90.3002 112,896 Vserver.vxd Windows Me
Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article.
Because this problem only affects computers that are on networks that route IPX, most users cannot be subjected to this denial of service.
For additional information about Windows 95 hotfixes, click the article number below to view the article in the Microsoft Knowledge Base: