A memory leak occurs if the DNS dynamic update protocol is enabled on a DHCP server that is running Windows Server 2003

A memory leak occurs on a DHCP server that is running Microsoft Windows Server 2003. When this problem occurs, you may experience one or more of the following symptoms:

• System Monitor indicates that the Private Bytes value of the Tcpsvcs.exe process continues to increase. (The performance log may also include this information.)
• The DHCP Server service does not work.
• The system runs slowly.

This problem does not occur if the DNS dynamic update protocol is disabled on the DHCP server. By default, this feature is enabled.

This problem occurs because the Dnsapi.dll module incorrectly manages some memory resources.

Hotfix information

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. 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: 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.

Prerequisites

To apply this hotfix, you must have Windows Server 2003 Service Pack 1 or Windows Server 2003 Service Pack 2 installed. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

Restart requirement

After you apply this hotfix, you may have to restart the server.

Hotfix replacement information

This hotfix does not replace any other hotfixes.

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 item in Control Panel.

Windows Server 2003 with Service Pack 2, x86-based versions

Windows Server 2003 with Service Pack 2, x64-based versions

Windows Server 2003 with Service Pack 2, Itanium-based versions

Windows Server 2003 with Service Pack 1, x86-based versions

Windows Server 2003, x64-based versions

Windows Server 2003 with Service Pack 1, Itanium-based versions

To work around this problem, disable the dynamic update feature on the DHCP server. To do this, follow these steps:

1. Click Start, click Run, type dhcpmgmt.msc, and then click OK.
2. In the console tree, right-click the node that corresponds to the DHCP server, and then click Properties.
3. On the DNS tab, click to clear the Enable DNS dynamic updates according to the settings below check box, and then click OK.
4. Restart the DHCP Server service. For example, type the following command at a command prompt, and then press ENTER:
   Net stop DHCPServer && Net Start DHCPServer

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

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