Cannot Disable ICMP Redirects By Changing "EnableICMPRedirect" Registry Value (293626)

The information in this article applies to:

Microsoft Windows 2000 Server SP1
Microsoft Windows 2000 Server SP2
Microsoft Windows 2000 Advanced Server SP1
Microsoft Windows 2000 Advanced Server SP2
Microsoft Windows 2000 Professional SP1
Microsoft Windows 2000 Professional SP2

This article was previously published under Q293626

IMPORTANT: This article contains information about modifying the registry. Before you modify the registry, make sure to back it up and make sure that you understand how to restore the registry if a problem occurs. For information about how to back up, restore, and edit the registry, click the following article number to view the article in the Microsoft Knowledge Base:

256986 Description of the Microsoft Windows Registry

SYMPTOMS

Windows 2000 can disable ICMP redirects by changing the value of the EnableICMPRedirect value in the following registry key:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters

The default value of 1 enables ICMP redirects, and 0 disables ICMP redirects. Modifying this registry value to 0 should prevent the creation of host routes when an ICMP redirect packet is received. However, changes to the value of this key have no effect on ICMP redirects.

CAUSE

This problem can occur when Windows 2000 looks for the EnableICMPRedirects (plural) registry value instead of the EnableICMPRedirect value.

RESOLUTION

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 should have the following file attributes or later:

   Date      Time         Version       Size      File name
   ---------------------------------------------------------
   5/29/2001   07:54a   5.0.2195.3649   118,800   Afd.sys
   5/31/2001   03:31p   5.0.2195.3649   104,720   Msafd.dll
   5/30/2001   02:28p   5.0.2195.3650   312,240   Tcpip.sys
   5/29/2001   07:53a   5.0.2195.3649    16,208   Tdi.sys
   5/31/2001   03:32p   5.0.2195.3649    17,680   Wshtcpip.dll

WORKAROUND

WARNING: If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.

To work around this problem, create the EnableICMPRedirects registry value so you can enable or disable ICMP redirects.

STATUS

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.

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 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

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:

249149 Installing Microsoft Windows 2000 and Windows 2000 Hotfixes

For additional information about ICMP redirects, click the article number below to view the article in the Microsoft Knowledge Base:

243427 ICMP Redirect Routes Override OSPF Routes

Modification Type:	Minor	Last Reviewed:	9/26/2005
Keywords:	kbHotfixServer kbQFE kbbug kbenv kbfix kbnetwork kbWin2000PreSP3Fix kbWin2000sp3fix KB293626