You have two DHCP servers that are running Windows Server 2008 R2.
You set up a split-scope configuration on both DHCP servers.
You make identical reservations on both DHCP servers.
A DHCP client that reserves an IP address broadcasts a DISCOVER packet and both DHCP servers respond to the DISCOVER packet by sending an OFFER packet.
The DHCP client receives a reserved IP address from one of the DHCP servers.
In this scenario, reservations on the other DHCP server are deleted incorrectly. Therefore, the reserved IP addresses may not be assigned to DHCP clients that reserve the addresses.
You have a DHCP server that is running Windows Server 2008 R2.
You create reservations for DHCP clients on this DHCP server.
The DHCP client releases the obtained IP address multiple times.
In this scenario, reservations on the DHCP server are deleted incorrectly. Therefore, the reserved IP addresses may not be assigned to DHCP clients that reserve the addresses.
This issue occurs because an incorrect logic is used in the DHCP server service when the DHCP server removes inactive entries from the database.
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.
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, submit a request to 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.
To apply this hotfix, you must be running Windows Server 2008 R2 on the computer.
To use the hotfix in this package, you do not have to make any changes to the registry.
You do not have to restart the computer after you apply this hotfix.
Hotfix replacement information
This hotfix does not replace a previously released hotfix.
The global version of this hotfix installs files that have the attributes that are listed in the following tables. The dates and the times for these files are listed in Coordinated Universal Time (UTC). The dates and the times for these files on your local computer are displayed in your local time together with your current daylight saving time (DST) bias. Additionally, the dates and the times may change when you perform certain operations on the files.
Windows Server 2008 R2 file information notes
Important Windows 7 hotfixes and Windows Server 2008 R2 hotfixes are included in the same packages. However, hotfixes on the Hotfix Request page are listed under both operating systems. To request the hotfix package that applies to one or both operating systems, select the hotfix that is listed under "Windows 7/Windows Server 2008 R2" on the page. Always refer to the "Applies To" section in articles to determine the actual operating system that each hotfix applies to.
The MANIFEST files (.manifest) and the MUM files (.mum) that are installed for each environment are listed separately in the "Additional file information for Windows Server 2008 R2" section. MUM and MANIFEST files, and the associated security catalog (.cat) files, are extremely important to maintaining the state of the updated component. The security catalog files, for which the attributes are not listed, are signed with a Microsoft digital signature.
For all supported x64-based versions of Windows Server 2008 R2
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
For more information about the Split-Scope Configuration, visit the following Microsoft Tech Web sites: