DHCP Server with Deactivated Scope Sends a DHCPNAK to Clients

ID: Q228597

The information in this article applies to:

Microsoft Windows NT Server version 4.0 SP4

SYMPTOMS

When you start a Dynamic Host Configuration Protocol (DHCP) client, it tries to renew its lease on an existing IP address for its scope (Requesting state). Or in the case of the client never having an address, it will try to obtain a lease for an IP address for its scope (Initializing state). In the case where there are two or more DHCP servers on the network configured to service this segment, and a DHCP server has the scope for this segment disabled, the client may receive a negative acknowledgment (DHCPNAK) from the DHCP server with the disabled scope. If the client is running Windows NT Server or Workstation, the DHCPNAK would cause an event to be logged to the Windows NT System Event log. This will also increase network traffic and cause the client to needlessly fall back to an Initializing state.

Previous to Windows NT 4.0 Service Pack 4, this behavior was not present. This applies to Windows NT 4.0 Service Pack 5 as well.

RESOLUTION

To resolve this problem, obtain the latest service pack for Windows NT 4.0 or the individual software update. For information on obtaining the latest service pack, please go to:

http://www.microsoft.com/Windows/ServicePacks/

Q152734 How to Obtain the Latest Windows NT 4.0 Service Pack

For information on obtaining the individual software update, contact Microsoft Product Support Services. For a complete list of Microsoft Product Support Services phone numbers and information on support costs, please go to the following address on the World Wide Web:

http://www.microsoft.com/support/supportnet/overview/overview.asp

STATUS

Microsoft has confirmed this to be a problem in the Microsoft products listed at the beginning of this article. This problem was first corrected in Windows NT 4.0 Service Pack 6.

MORE INFORMATION

Administrators find that configuring two DHCP servers for the same scope then disabling one is an easy way to provide limited fault tolerance.

When the server with the active scope is unavailable, the DHCP server with the deactivated scope will assume the responsibilities for the DHCP clients of that scope.

For more information on how to configure DHCP, please see the following article in the Microsoft Knowledge Base:

Q139904 How to Configure Your DHCP Server Scope

Additional query words:

Keywords :
Version : winnt:4.0 SP4
Platform : winnt
Issue type : kbbug