Configuring the DHCP Cleanup Cycle

On a Windows Server 2003 DHCP server, when an DHCP lease expires, the lease is marked for deletion in the DHCP database. It isn’t immediately deleted from the database however. Instead, DHCP clients are granted a 4 hour reprieve just in case they still need to use the address so they can renew it. After this grace period elapses, the expired lease can be reused by another client requesting an IP address. Once per hour the DHCP server runs a cleanup cycle which reclaims unused leases. If you have lots of DHCP clients issuing requests on your network and there are no leases available, the DHCP cleanup cycle runs immediately, reclaiming leases marked for deletion so new leases can be issued to clients requesting them. You can modify the cleanup cycle to run more frequently (if you are short of available leases) or less frequently (if you have a large pool of available leases) by modifying the registry key HKLMSystemCurrentControlSetServicesDHCPServerParametersLeaseExtension.

Article written by MyComputerAid.com