When you have a program that sends IP multicasts with a time-to-live (TTL) setting of 0 (zero) to communicate with other local programs, multicasts with a TTL setting of 0 should not be transmitted on the network (they should only be looped back to other programs in the local computer). However, if you monitor network traffic you see that IP multicasts with a TTL setting of 0 are transmitted on the network. This may cause the network to become overloaded.

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The TCP/IP stack does not handle IP multicasts correctly and transmits the last fragment of each multicast datagram on the network.

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A supported hotfix is available from Microsoft. However, this hotfix is intended to correct only the problem that is described in this article. Apply this hotfix only to systems that are experiencing this specific problem.

If the hotfix is available for download, there is a "Hotfix download available" section at the top of this Knowledge Base article. If this section does not appear, submit a request to Microsoft Customer Service and Support to obtain the hotfix.

Note If additional issues occur or if any troubleshooting is required, you might have to create a separate service request. The usual support costs will apply to additional support questions and issues that do not qualify for this specific hotfix. For a complete list of Microsoft Customer Service and Support telephone numbers or to create a separate service request, visit the following Microsoft Web site: Note The "Hotfix download available" form displays the languages for which the hotfix is available. If you do not see your language, it is because a hotfix is not available for that language.

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Windows 2000

To resolve this problem, obtain the latest service pack for Windows 2000. For additional information, click the following article number to view the article in the Microsoft Knowledge Base: The English version of this fix should have the following file attributes or later:

   Date         Time   Version         Size     File name
   ---------------------------------------------------------
   27-Jul-2001  01:04  5.00.2195.3951  118,864  Afd.sys
   03-Aug-2001  12:17  5.00.2195.3952  105,232  Msafd.dll
   27-Jul-2001  06:01  5.00.2195.3958  312,496  Tcpip.sys
   30-Jul-2001  20:15  5.00.2195.3988   16,240  Tdi.sys
   03-Aug-2001  12:17  5.00.2195.3649   17,680  Wshtcpip.dll
				

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Windows XP

The English version of this fix should have the following file attributes or later:

   Date         Time   Version             Size   File name
   --------------------------------------------------------------
   04-Dec-2001  12:02  5.1.2600.21       318,080  Tcpip.sys
				

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Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article. This problem was first corrected in Windows 2000 Service Pack 3.

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For additional information about dialup networking and Windows 2000, click the article number below to view the article in the Microsoft Knowledge Base: For additional information multicast packets and Microsoft Windows 98, Microsoft Windows 98 Second Edition, and Microsoft Windows Millenium Edition, click the article number below to view the article in the Microsoft Knowledge Base: For additional information about how to install Windows 2000 and Windows 2000 hotfixes at the same time, click the article number below to view the article in the Microsoft Knowledge Base:

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