This article was previously published under Q327875
When you move a portable computer to a different subnet, you may not automatically receive a new IP address from the Dynamic Host Configuration Protocol (DHCP) server.
This problem may occur if both of the following conditions exist:
You use a Windows NT 4.0-based DHCP server.
You put your portable computer on standby, move the computer to a different subnet, and then you resume your computer from standby.
In this situation, when the client sends a request to the DHCP server, the DHCP server does not recognize that the gateway IP address field (GIADDR) is for a different subnet. The DHCP server incorrectly responds to the client request with a DHCPACK message, instead of a DHCPNACK message. Because of this, you do not receive a new IP address.
A supported fix is now available from Microsoft, but it is only intended to correct the problem that is described in this article. Apply it only to computers that are experiencing this specific problem.
To resolve this problem, contact Microsoft Product Support Services to obtain the fix. For a complete list of Microsoft Product Support Services phone numbers and information about support costs, visit the following Microsoft Web site:
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.
The global version of this fix 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 -------------------------------------------------------- 19-Sep-2002 17:19 4.0.1381.7195 127,760 Dhcpssvc.dll
Note Because of file dependencies, this hotfix requires Microsoft Windows NT 4.0 Service Pack 6a.
To work around this problem, use the ipconfig command to release and renew the client IP address:
Click Start, and then click Run.
In the Open box, type cmd, and then click OK.
At the command prompt, type the following commands, pressing ENTER after each command:
ipconfig /release ipconfig /renew
Type exit, and then press ENTER to quit the command prompt.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article.
For additional information about DHCP, click the following article numbers to view the articles in the Microsoft Knowledge Base: