Starting from today February 1, 2019 (DNS Flag Day), DNS (Domain Name System) providers will stop supporting DNS servers that are non compliant with Extension mechanisms for DNS (EDNS) protocol. In order to be compliant for EDNS, not only DNS servers should support this protocol, but also network devices (firewalls) should be aware for the necessary adjustments to support this protocol as a benefit for all us (internet users). Currently all major "players" are supporting DNS Flag Day.
For more info regarding DNS Flag Day, you can find on https://dnsflagday.net/. There you can also check your domain (hosting DNS zone servers) if EDNS is fully supported.
Microsoft DNS servers are supporting EDNS, but tests will show minor issue on implementation on some extensions of the protocol. Those errors will not affect domain name resolution on February 1, 2019 and later. According from Microsoft, those errors will be fixed in some of the next patch Tuesdays.
More info from Microsoft about this issue on Windows Server Domain Name System (DNS) Flag Day Compliance.
And, also please check if you're having some older network appliance which will prevent EDNS usage on your DNS servers. Please don't disable EDNS as a permanent problem resolution, Some DNS name queries are unsuccessful after you deploy a Windows-based DNS server.
Happy DNS Flag Day !
For more info regarding DNS Flag Day, you can find on https://dnsflagday.net/. There you can also check your domain (hosting DNS zone servers) if EDNS is fully supported.
Microsoft DNS servers are supporting EDNS, but tests will show minor issue on implementation on some extensions of the protocol. Those errors will not affect domain name resolution on February 1, 2019 and later. According from Microsoft, those errors will be fixed in some of the next patch Tuesdays.
More info from Microsoft about this issue on Windows Server Domain Name System (DNS) Flag Day Compliance.
And, also please check if you're having some older network appliance which will prevent EDNS usage on your DNS servers. Please don't disable EDNS as a permanent problem resolution, Some DNS name queries are unsuccessful after you deploy a Windows-based DNS server.
Happy DNS Flag Day !
