Multicasts with a TTL Setting of Zero Are Transmitted on the Network (311935)

SYMPTOMS

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 are not supposed to be transmitted on the network. Instead, they are only supposed to be looped back to other programs in the local computer. However, IP multicasts with a TTL setting of 0 may be transmitted on the network. This may cause the network to become overloaded. This problem was partially addressed by the hotfix that is described in the following Microsoft Knowledge Base article:

301453 Multicast Packets with a TTL Setting of 0 Are Transmitted by the Windows 2000 TCP/IP Stack and the Windows XP TCP/IP Stack

The Q301453 hotfix prevents transmission of multicasts with a TTL of 0 on LAN connections. However, after you apply the hotfix from Q301453, IP multicasts with a TTL setting of 0 may still be transmitted over a RAS connection.

CAUSE

The TCP/IP stack was not handling IP multicasts correctly and was transmitting the last fragment of each multicast datagram on the network. The hotfixes from Q301453 corrected this problem, and modified TCP/IP to inform lower layers not to transmit multicasts with a TTL of 0. However, this hotfix only cured the problem on LAN links. Even with this hotfix in place, NDISWAN was ignoring this new information that was passed to it by TCP/IP, and was still transmitting multicasts with a TTL of 0 on RAS links.

RESOLUTION

Windows XP

To resolve this problem, obtain the latest service pack for Windows XP. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:

322389 How to Obtain the Latest Windows XP Service Pack

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

   Date         Time   Version            Size    File name
   -----------------------------------------------------------
   28-Nov-2001  15:38  5.1.2600.21        87,296  Ndiswan.sys
   02-Nov-2001  16:50  5.1.2600.17         3,584  Spmsg.dll
   08-Nov-2001  13:56  5.1.2600.19        38,912  Spuninst.exe

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:

260910 How to Obtain the Latest Windows 2000 Service Pack

The English version of this fix for Windows 2000 has the file attributes (or later) that are listed in the following table. The dates and times for these files are listed in coordinated universal time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time tool in Control Panel.


   Date         Time   Version        Size     File name
   --------------------------------------------------------
   19-Nov-2001  16:42  5.0.2195.4667  118,896  Afd.sys
   08-May-2002  12:20  5.0.2195.4874  105,232  Msafd.dll
   22-Mar-2002  12:18  5.0.2195.5241   89,712  Ndiswan.sys
   19-Apr-2002  17:45  5.2.2.2          3,584  Spmsg.dll
   19-Apr-2002  17:46  5.2.2.2         44,032  Spuninst.exe
   12-Jun-2001  22:05  5.0.2195.3727    3,856  Svcpack1.dll
   06-Apr-2002  16:50  5.0.2195.5542  313,168  Tcpip.sys
   30-Jul-2001  20:15  5.0.2195.3988   16,240  Tdi.sys
   08-May-2002  12:20  5.0.2195.4874   17,680  Wshtcpip.dll
   22-Mar-2002  12:18  5.0.2195.5241   89,232  Ndiswan.sys
   19-Apr-2002  17:46  5.2.2.2         10,240  Spcustom.dll

MORE INFORMATION

For additional information about how to obtain a hotfix for Windows 2000 Datacenter Server, click the article number below to view the article in the Microsoft Knowledge Base:

265173 The Datacenter Program and Windows 2000 Datacenter Server Product

For additional information about how to install multiple hotfixes with only one reboot, click the article number below to view the article in the Microsoft Knowledge Base:

296861 Use QChain.exe to Install Multiple Hotfixes with One Reboot