Dns is not updating records
Imagine if an important server's DNS A record suddenly gets changed to the wrong IP. DDNS can sometimes go on a walkabout and it's important to know where to start troubleshooting if this happens.
Let's demonstrate a typical troubleshooting scenario that you may come across with DDNS.
If it's started, ensure there's no events in the computer's System event log that indicate a problem. Check the advanced DNS client NIC setting The "Register this connection's addresses in DNS" should be on by default, but we've seen instances where it's disabled through some kind of policy.
Please see For a DHCP client, when some particular action causes its IP address to change, such as a DHCP lease renewal, if the client supports it, it will send Client FQDN information (DHCP option 81 flags) to the DHCP server.
When the NS records have been updated to point to Office 365, your domain is all set up.
Email will be routed to Office 365, and traffic to your website address will continue to go to your current website host.
Some customers have reported issues with Microsoft Dynamic Updates after installing virtual appliances (VAs) in their environment or installing the Umbrella Roaming Client on some machines.
The most commonly reported symptom is that clients cannot resolve A or PTR records for other client machines while using the VAs or the Roaming Client for DNS resolution.