This article was previously published under Q182047
This article has been archived. It is offered "as is" and will no longer be updated.
When a large number of scopes are configured on a Windows NT 4.0DHCP server, performance degrades to where it cannot keep up with largeclient loads such as those experienced after a power failure, or at peaknetwork startup times.
A list of scopes is maintained in the registry. When a DHCP DISCOVER orDHCP REQUEST is received, it must be matched against the configured scopesto see if the server is able to provide services to the client subnet. Thisprocess of searching through the scopes was not optimized for large numbersof scopes. Additionally, some database calls could experience suboptimalperformance caused by nonoptimal database buffer initialization.
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
NOTE: This hotfix supersedes the fixes referred to in the followingarticles in the Microsoft Knowledge Base:
ARTICLE-ID: 141496 TITLE : DHCP Client Comment Disappears When Obtaining IP Address
ARTICLE-ID: 167708 TITLE : BootP Client Names Disappear in DHCP Manager
ARTICLE-ID: 163055 TITLE : DHCP Client May Fail with WinNT 4.0 SP2 Multinetted DHCP Server
ARTICLE-ID: 175035 TITLE : Diskless Workstations Cannot Find BOOTP Server with DHCP
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.
The updated file caches the entire scope list in memory, and uses a binarysearch to quickly determine if the server has a scope that is relevant toeach client request. This update dramatically reduces the number of timesthat registry keys are opened and searched. It also provides more buffersfor interaction with the database, which improves database throughput.