During the cleanup of DNS records associated with decommissioned domain controllers, administrators may observe that certain A and SRV records are not removed as expected. Standard cleanup operations, including DNS dynamic updates (DU) and the use of the 'nltest /dsderegdns' command, appear to execute successfully according to log file analysis. Despite this, the DNS records remain, indicating that the cleanup process did not complete as intended.
The issue is not caused by a fault in the product or the commands invoked. Instead, the failure occurs because the Netlogon and DNS services are unable to process all cleanup requests. In environments with a large number of Active Directory sites, the Netlogon service generates an excessive volume of DNS update queries. This behavior overloads the DNS server with redundant or low-value requests, eventually leading to the dropping of valid cleanup requests.
Microsoft has acknowledged that this function call can be time-consuming and may generate significant network traffic in enterprises with many sites.
WORKAROUND:
None
STATUS
An Enhancement ID - ADO-599559 has been submitted for future product versions to improve support for enterprises with extensive A or SRV records.
