Article ID: 261964
Article Last Modified on 2/28/2007
APPLIES TO
- Microsoft Windows 2000 Server
- Microsoft Windows 2000 Advanced Server
This article was previously published under Q261964
SUMMARY
After a Dynamic Host Configuration Protocol (DHCP) client lease expires, it is not immediately scavenged from the database. A grace period of four hours is added to the end of the lease to prevent against clock drift between the DHCP client and server. On a Windows 2000-based DHCP server, leases are scavenged from the database if they meet the criteria of (ExpirationTime + 4 hours).
MORE INFORMATION
In Windows 2000, leases that are expired but fall within the grace period appear in Microsoft Management Console (MMC) as inactive leases. Statistically, they are counted with active and excluded leases as "In Use." However, any lease that falls within the grace period (inactive) may be issued by the DHCP server if the available leases fall to 0.
This behavior may become apparent if you are using short lease times and short scavenge intervals. The DHCP snap-in in MMC may display Scope Full icons (with an exclamation point on the Scope and Server icons) and the event log may contain event ID 1020. These notifications are based on the number of "In Use" addresses and occur even though inactive leases may be available to be distributed to requesting clients.
Sample event ID 1020:
For additional information, click the article number below to view the article in the Microsoft Knowledge Base:
153072 Leases Retained in DHCP Database For One Day After Expiration
Keywords: kbdhcp kbinfo KB261964
