DNS Flag Day is February 1, 2019. On this day, DNS providers will stop supporting certain workarounds that enable name resolution for domains hosted on DNS servers that don't fully conform to EDNS standards. For more information, visit dnsflagday.net. You can test domains for compliance by using tools on that page.
At this time, DNS services across Microsoft are testing as "All ok" or "Minor problems detected" on dnsflagday.net. Domains that test as "Minor problems detected" will not be affected on DNS Flag Day. Azure DNS and Azure Traffic Manager fixes are currently being rolled out to resolve these minor issues. Fixes for microsoft.com, xbox.com, and other domains are in progress. Some of these fixes will not be fully deployed until after DNS Flag Day. This is not expected to cause any impact to our customers or services.
We're committed to resolving all EDNS compliance issues in the coming weeks. Our goal is to have zero impact for our customers on DNS Flag Day and to resolve all EDNS compliance issues in all our services in a timely manner.
What to do next?
No action is required from Azure DNS and Azure Traffic Manager customers. There will be no impact on DNS Flag Day for any of our customers.
Customers with dependencies on DNS domains hosted on any Microsoft DNS service also need to take no action. There will be no impact on DNS Flag day. Some services will not have all EDNS compliance issues fixed by February 1, but none of these issues will affect name resolution.