DHCP Clients Obtain IP Address from Old DHCP Scope Range (175913)


The information in this article applies to:

  • Microsoft Windows NT Workstation 3.5
  • Microsoft Windows NT Workstation 3.51
  • Microsoft Windows NT Workstation 4.0
  • Microsoft Windows NT Server 3.5
  • Microsoft Windows NT Server 3.51
  • Microsoft Windows NT Server 4.0
  • Microsoft Windows for Workgroups 3.11
  • Microsoft TCP/IP-32 for Windows for Workgroups 3.11
  • Microsoft TCP/IP-32 for Windows for Workgroups 3.11a
  • Microsoft TCP/IP-32 for Windows for Workgroups 3.11b
  • Microsoft Windows 95
This article was previously published under Q175913
IMPORTANT: This article contains information about editing the registry. Before you edit the registry, make sure you understand how to restore it if a problem occurs. For information about how to do this, view the "Restoring the Registry" Help topic in Regedit.exe or the "Restoring a Registry Key" Help topic in Regedt32.exe.

SYMPTOMS

After you change the Dynamic Host Configuration Protocol (DHCP) scope on your Microsoft Windows NT DHCP Server, your DHCP clients may continue to lease addresses from the original or old scope. This may occur even if the old scope information is non-existent in DHCP Admin.

NOTE: Stopping and restarting the DHCP Server Service or restarting the DHCP Server has no effect on this issue and attempts to release or renew the address on the client has no effect.

CAUSE

A registry key with the old DHCP scope information on the DHCP Server still exists.

RESOLUTION

You will need to remove the registry key that references the old scope range by performing the following steps:

WARNING: Using Registry Editor incorrectly can cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk.

For information about how to edit the registry, view the "Changing Keys And Values" Help topic in Registry Editor (Regedit.exe) or the "Add and Delete Information in the Registry" and "Edit Registry Data" Help topics in Regedt32.exe. Note that you should back up the registry before you edit it.

  1. Start Registry Editor (Regedt32.exe), and go to the following subkey: 
          HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services
      \DHCPServer\Configuration\Subnets\<Subnet ID>
      \IpRanges\<Old scope range>
    NOTE: The above registry key is one path; it has been wrapped for readability.
  2. Click <Old scope range>, click Delete from the Edit menu, and click Yes in the Warning dialog box.
It is not necessary to restart the DHCP Server. After this key is deleted, DHCP clients will obtain IP addresses from the new scope range.
Modification Type:MajorLast Reviewed:12/5/2003
Keywords:kbinterop kbnetwork KB175913 kbAudDeveloper
©2003 Microsoft Corporation. All rights reserved.