Windows 2000's DNS service supports the scavenging feature, which helps you ensure that DNS records managed by the service are up to date. Scavenging is particularly important if you use Dynamic DNS to automatically register client host names when their IP addresses change, as is often the case when the clients receive address assignments through DHCP.

Over time, client host records in a zone can become stale, and scavenging removes these records. Removing the records improves DNS server and zone transfer performance, and it ensures that host records don't conflict with older records.

You can configure scavenging through a zone's properties. Open the DNS console, right-click the zone, and choose Properties. On the General tab, click Aging to open the Zone Aging/Scavenging Properties dialog box. Set the Refresh Interval and the No-refresh Interval using the drop-down lists, select the Scavenge Stale Resource Records check box, and click OK to close both dialog boxes.

You can also configure scavenging for zones globally, rather than for an individual zone, by editing the server's properties. In the DNS console, right-click the server, and choose Set Aging/Scavenging For All Zones. The resulting dialog box is the same as that for an individual zone.