This article was previously published under Q163055
This article has been archived. It is offered "as is" and will no longer be updated.
A DHCP client may fail to obtain a DHCP lease if multiple logical subnetsexist and there is a Windows NT 4.0 Service Pack 2 (SP2) DHCP server on thenetwork. Also, you may receive the following error message when you run theIPCONFIG /RENEW command:
Access Denied - Renewing Adapter "xxxx"
Prior to Service Pack 2, when multiple logical subnets existed, the DHCPclient was able to receive the DHCPOFFER and send a DHCPREQUEST to theoffering DHCP server. After applying Service Pack 2, the DHCP servers onother logical subnets issue a DHCPNACK, which forces the client to releasethe address and perform a DHCPDISCOVER again.
In addition to the above error message, you may receive the following eventlog messages:
On the Client
Event ID: 1006 Source: Dhcp Type: Warning Category: None Description: DHCP service is shutting down. The following error occurred: Access is denied.
On the Server
Event ID: 1011 Source: DhcpServer Type: Warning Category: None Description: The DHCP server issued a NACK to the client (MAC Address of the Requesting Client) for the address (Requested IP Address) request.
Windows NT 4.0 SP2 DHCP servers issue a DHCPNACK to any DHCPREQUEST thatdoes not appear to be valid for the subnet. This problem occurs when youare using multiple logical IP subnets (multinetting) and two DHCP serverson the same physical network are serving two different logical subnets.
For example, a client broadcasts DHCPREQUEST and receives ACK from server Aand NACK from server B. Because there is no communication between server Band server A, server B is not aware of the existence of server A. If itdoes not send a NACK, then a client who has just moved to this network willnever know that its old address is invalid.
To resolve this problem, obtain the latest service pack for Windows NT 4.0 or Windows NT Server 4.0, Terminal Server Edition. For additional information, click the following article number to view the article in theMicrosoft Knowledge Base:
152734 How to Obtain the Latest Windows NT 4.0 Service Pack
To workaround this issue, use one of the following:
Windows NT 4.0 SP2 includes the ability to create DHCP superscopes. After creating a scope and defining each logical subnet in a superscope, the DHCP server recognizes the DHCPREQUEST as valid and will not NACK the request.
For example, you have a multinet environment with the following DHCP servers on a single LAN:
192.168.10.1 192.168.20.1 192.168.30.1
On each DHCP server you must create a superscope with a minimum of one IP address from each of the 10.x, 20.x and 30.x scopes. Be sure not to duplicate IP addresses in the scopes.
Another possibility is to take advantage of the superscoping feature and create one DHCP server to serve all scopes.
For more information on superscopes, please see the following article inthe Microsoft Knowledge Base:
ARTICLE-ID: 161571 TITLE : Using DHCP "Superscopes" to Serve Multiple Logical Subnets
Microsoft has confirmed that this is a problem in Windows NT 4.0 and Windows NT Server 4.0, Terminal Server Edition. This problem was first corrected in Windows NT 4.0 Service Pack 4.0 and Windows NT Server 4.0, Terminal Server Edition Service Pack 4.