Recall from earlier that a refresh is a dynamic update where we are not changing the host/IP of a resource record, just touching the timestamp.
If a client changes the IP of a host record this is considered an “update” and is exempt from the No-refresh interval.
Scavenging gets set on a resource record in one of three ways.
The first is by someone coming in here, checking the “Delete this record when it becomes stale” checkbox and hitting apply.
Because of the time it takes scavenging to do it’s thing people find this command and get tempted to give it a try. Before a server will even look at a record to see if it will be scavenged the zone must have scavenging enabled.
To access the scavenging settings for a zone right click the zone, select properties then on the general tab hit the “Aging” button. If you view it on any DNS server where this zone is replicated it will be the same.
Unless you check the subsequent box “Apply these settings to the existing Active Directory-integrated zones” it will not touch existing zones.
So you now have a resource resource record set to scavenge and a zone set to scavenge.
This is done by any server that hosts the AD integrated zone.
This timestamp will be replicated around and the No-refresh interval begins again.
If for some reason the client fails to update it’s record during the refresh interval it becomes One last thing before we leave the zone setting behind.
of these must elapse before a record can be deleted.
The No-refresh interval is a period of time during which a resource record cannot be refreshed.