Article ID: 833009 - View products that this article applies to.
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:
(http://support.microsoft.com/kb/256986/ )Description of the Microsoft Windows Registry
When a computer that is running Internet Security and Acceleration Server (ISA) 2000 starts, ISA does not block external Internet Control Message Protocol (ICMP) traffic even if ISA policies do not permit the traffic. For example, you may be able to PING ISA Server for a short time period after you start the computer. You can correct this problem if the following is true:
The problem may occur if the TCP/IP stack is operational before the ISA Server packet filter driver is loaded and running. In this scenario, a small time gap occurs when traffic is not blocked.
Hotfix informationA 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. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next software update that contains this hotfix.
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, contact 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:
PrerequisitesISA Server Service Pack 1
Restart requirementAfter you install this hotfix, you must add a registry key as described in the "More Information" section. After you install this key, you must restart your computer.
Hotfix replacement informationThis hotfix does not replace any other hotfixes.
File informationThe English version of this hotfix 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 -------------------------------------------------- 02-Feb-2004 21:38:14 3.0.1200.301 41,584 Mspfltex.sys 02-Feb-2004 21:39:28 3.0.1200.301 518,928 Stpsrvex.dll
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section of this article.
This hotfix will change the load order of the ISA Server packet filter driver and the operating system packet filter driver. The ISA Server packet filter driver will load earlier in the startup sequence. After you install and enable this hotfix, ISA Server will block any incoming or outgoing ICMP traffic on all network adapters until the ISA Server Control service is started, and filtering can be applied according to static filters and rules.
How to enable this hotfixAfter you install this hotfix, follow these steps to enable it.
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.
When this hotfix must not be installedMicrosoft does not recommend that you install this hotfix when no external network adapter is available to ISA Server, as in the following circumstances:
What occurs if you install and enable this hotfix on a computer that has no external network adapterIf you install this hotfix on a computer that has no external network adapter, the following issues may occur:
NoteIf you install ISA server in cache only mode, these issues will not occur.
When the hotfix must be removedYou must remove the hotfix in the following circumstances:
How to remove the hotfix
If you want to return to the driver load order and traffic blocking behavior that existed before you installed this hotfix, follow these steps to remove the hotfix:
How to enable packet filtering in ISA ServerTo enable packet filtering, follow these steps:
How to browse ISA Server servicesTo browse ISA Server services, follow these steps:
Article ID: 833009 - Last Review: June 14, 2007 - Revision: 1.11
Contact us for more help
Connect with Answer Desk for expert help.