If dynamic DNS updates are enabled on your storage system, Data ONTAP periodically sends updates to the primary master DNS server for its zone. Updates are also sent if any DNS information changes on your system. Your storage system finds out the primary master DNS server for its zone by querying the DNS servers configured in your storage system's /etc/resolv.conf file. The primary master DNS server might be different from the ones configured in your storage system's /etc/resolv.conf file.
By default, periodic updates are sent every 12 hours. A time-to-live (TTL) value is assigned to every DNS update sent from your storage system. The TTL value defines the time for which a DNS entry is valid on the DNS server. By default, the TTL value is set to 24 hours, and you can change it.
When your storage system sends an update to the DNS server, it waits up to five minutes to receive an acknowledgement of the update from the server. If it does not receive an acknowledgement, the storage system sends the update again. This time, the storage system doubles the waiting interval (to 10 minutes), before sending the update. The storage system continues to double the waiting interval with each retry until a waiting interval of 160 minutes or TTL/2, whichever is less, is reached.