Microsoft KB Archive/914842

= How to simplify the creation and maintenance of Internet Protocol security filters in Windows XP =

Article ID: 914842

Article Last Modified on 4/5/2006

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APPLIES TO


 * Microsoft Windows XP Professional
 * Microsoft Windows XP Professional x64 Edition

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Important This article contains information about how to modify the registry. Make sure to back up the registry before you modify it. Make sure that you know how to restore the registry if a problem occurs. For more information about how to back up, restore, and modify the registry, click the following article number to view the article in the Microsoft Knowledge Base:

256986 Description of the Microsoft Windows registry



INTRODUCTION
This article describes a hotfix that you can apply to simplify the creation and maintenance of Internet Protocol security (IPsec) filters in Microsoft Windows XP.

This hotfix adds functionality to Windows that enables you to use an IPsec &quot;Simple Policy.&quot; For most environments, the installation of this hotfix lets you reduce the number of IPsec filters that are required for a Server Isolation deployment or for a Domain Isolation deployment. You can reduce the number of IPsec filters from many hundreds of filters to only two filters.



MORE INFORMATION
Server Isolation and Domain Isolation are two major network security deployment scenarios that can exist together with a Windows Firewall deployment. These two deployment scenarios are based on the use of IPsec to isolate network traffic. However, the number of IPsec filters that administrators must create and maintain in these two scenarios frequently acts as a disincentive. Currently, administrators who want to implement Server Isolation or Domain Isolation by using IPsec must create an isolation policy that contains a significant number of rules. Frequently, administrators must create 300 to 500 rules. For example, rules are required to specify the subnets to isolate, the services that are required by domain controllers and DNS servers, and so on.

This hotfix removes the requirement for explicit network infrastructure permit filters and for special filters to help secure a subnet. To remove this requirement, this hotfix introduces enhanced behavior for the &quot;fallback to clear&quot; functionality. The fallback to clear functionality is enhanced in the following two ways:
 * The fallback to clear time-out value is reduced from 3 seconds to 500 milliseconds (ms).
 * Credential and policy mismatch failures are now permitted to use the fallback to clear functionality.

Hotfix information
A supported hotfix is now available from Microsoft, but it is only intended to correct the problem that is described in this article. Only apply it to systems that are experiencing this specific problem. This hotfix may receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next Windows XP service pack that contains this hotfix.

To resolve this problem immediately, contact Microsoft Product Support Services to obtain the hotfix. For a complete list of Microsoft Product Support Services telephone numbers and information about support costs, visit the following Microsoft Web site:

http://support.microsoft.com/contactus/?ws=support

Note In special cases, charges that are ordinarily incurred for support calls may be canceled if a Microsoft Support Professional determines that a specific update will resolve your problem. The usual support costs will apply to additional support questions and issues that do not qualify for the specific update in question.

Prerequisites
You must be running Windows XP Professional with Service Pack 2 (SP2) to apply this hotfix.

Restart requirement
You do not have to restart the computer after you apply this hotfix. However, you must restart the Policyagent service to apply the changes after you apply this hotfix.

Hotfix replacement information
This hotfix does not replace any other hotfixes. However, this hotfix replaces earlier versions of the Oakley.dll file.

File information
The English version of this hotfix has the file attributes (or later file attributes) 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.

Hotfix installation information
Warning Serious problems might occur if you modify the registry incorrectly by using Registry Editor or by using another method. These problems might require that you reinstall your operating system. Microsoft cannot guarantee that these problems can be solved. Modify the registry at your own risk.

By default, the functionality that this hotfix package provides is not enabled. To enable the functionality that this hotfix provides, you must modify the following registry subkey:

This IKEFlags registry entry is a REG_DWORD type. You must manually create this entry if it does not already exist.

Important This registry entry is interpreted as a bit-mask. Therefore, if the current value of the entry is not 0x0, we recommend that you carefully consider any modifications that you make to the entry to preserve existing settings.

To enable the Simple Policy functionality that this hotfix provides, you must set the following bits in the IKEFlags registry entry:

0x14

This value contains two individual settings that you can independently enable, if you require this level of granularity. These two values are as follows:
 * 0x4

This setting enables improved fallback to clear behavior.
 * 0x10

This setting adds more notification messages (notifies) to decrease the fallback to clear time in a Domain Isolation boundary zone scenario.

Note We recommend that you use a value of 0x14 unless you have a specific requirement to limit the sending of Internet Key Exchange (IKE) &quot;notifies.&quot;



STATUS
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the &quot;Applies to&quot; section.



MORE INFORMATION
This hotfix is also available for Microsoft Windows Server 2003. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

914841 How to simplify the creation and maintenance of Internet Protocol security filters in a Windows Server 2003-based environment

For more information, click the following article number to view the article in the Microsoft Knowledge Base:

824684 Description of the standard terminology that is used to describe Microsoft software updates

Additional query words: IPSec simple policy IKE

Keywords: kbwinxpsp2fix kbwinxppresp2fix kbfix kbbug kbmsccsearch kbpubtypekc kbhotfixserver KB914842

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