DOCUMENT:Q154174 [crossnet]

TITLE   :Invalid ICMP Datagram Fragments Hang Windows NT, Windows 95   

PRODUCT :Microsoft Windows NT and Windows 95

PROD/VER:3.51 4.00

OPER/SYS:WINDOWS

KEYWORDS:kbbug3.51 kbbug4.00 kbfile kbfix3.51 kbfix4.00 NTSrvWkst nttcp



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The information in this article applies to:



 - Microsoft Windows NT Workstation version 3.51 and 4.0

 - Microsoft Windows NT Server version 3.51 and 4.0

 - Microsoft Windows 95

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SYMPTOMS

========



Computers running Windows NT or Windows 95 may stop responding (hang) when

they receive corrupt Internet Control Message Protocol (ICMP) datagram

fragments from a client.



RESOLUTION

==========



Microsoft has updated the TCP/IP protocol stack to correct this problem.

Instructions for installing it are available from Microsoft support

channels or directly from the Internet locations below.



Windows NT 4.0

--------------



NOTE: Service Pack 3 must be applied to Windows NT 4.0 prior to applying

this fix.



This hotfix has been posted to the following Internet location:



   ftp://ftp.microsoft.com/bussys/winnt/winnt-public/fixes/usa/NT40/

   hotfixes-postSP3/icmp-fix



Windows NT 3.51

---------------



NOTE: Service Pack 5 must be applied to Windows NT 3.51 prior to applying

this fix.



This hotfix has been posted to the following Internet location:



   ftp://ftp.microsoft.com/bussys/winnt/winnt-public/fixes/usa/NT351/

   hotfixes-postSP5/icmp-fix



Windows 95

----------



This issue is resolved by the following updated file for Windows 95 and

OSR2:



   Vip.386 version 4.0.956 (dated 6/30/97) or later



This file is included in the self-extracting Vipupd.exe file.



To install this update, follow these steps:



1. Download the Vipupd.exe file from the online service listed below to

   an empty folder.



2. In My Computer or Windows Explorer, double-click the Vipupd.exe file

   you downloaded in step 1.



3. Follow the instructions on the screen.



The following file are available for download from the Microsoft

Software Library:



 ~ VIPUPD.EXE



For more information about downloading files from the Microsoft Software

Library, please see the following article in the Microsoft Knowledge Base:



   ARTICLE-ID: Q119591

   TITLE     : How to Obtain Microsoft Support Files from Online Services



The following files are installed by Vipupd.exe:



   File name  Version    Date/Time        Size     Destination folder

   ----------------------------------------------------------------------

   Vip.386    4.00.956   6/30/97 9:54am   171,672  Windows\System



STATUS

======



Microsoft has confirmed this to be a problem in Windows NT versions 3.51

and 4.0.



A supported fix is now available, but has not been fully regression-tested

and should be applied only to systems experiencing this specific problem.

Unless you are severely impacted by this specific problem, Microsoft

recommends that you wait for the next Service Pack that contains this fix.

Contact Microsoft Technical Support for more information.



Microsoft has confirmed this to be a problem in Microsoft Windows 95 and

OEM Service Release 2 (OSR2). An update to address this problem is now

available, but is not fully regression tested and should be applied only

to computers experiencing this specific problem. Unless you are severely

impacted by this specific problem, Microsoft does not recommend

implementing this update at this time. Contact Microsoft Technical Support

for additional information about the availability of this update.



Additional query words: prodnt 4.00 3.51 win95 ssping spingnuke denial of

service attack hangs



============================================================================



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