See https://dnsflagday.net/
Since Sonic is my secondary DNS I decided to test my DNS service (using the above webpage) and find it has issues, having to do with Sonic DNS not responding fast enough. An email to support about this was responded to a couple days later saying they can't help.
I then tried the same test with sonic.net and it too has exact same problem. Services such as Azure etc are fixing this. And so are vendors. As per ISC:
Since Sonic is my secondary DNS I decided to test my DNS service (using the above webpage) and find it has issues, having to do with Sonic DNS not responding fast enough. An email to support about this was responded to a couple days later saying they can't help.
I then tried the same test with sonic.net and it too has exact same problem. Services such as Azure etc are fixing this. And so are vendors. As per ISC:
Flag Day being Feb 1. This problem with Sonic DNS needs to be fixed (which will also fix my secondary DNS issue)....A number of DNS software and service providers have announced that we will all cease implementing DNS resolver workarounds to accommodate DNS authoritative systems that don’t follow the Extensions to DNS (EDNS) protocol. Each vendor has pledged to roll out this change in some version of their software by the ‘Flag Day.’
...
Non-compliant domains may become unavailable
Domains served by DNS servers that are not compliant with the standard will not function reliably when queried by resolvers that have been updated to the post-Flag Day version, and may become unavailable via those updated resolvers.
If your company’s DNS zones are served by non-compliant servers, your online presence will slowly degrade or disappear as ISPs and other organizations update their resolvers. When you update your own internal DNS resolvers to versions that don’t implement workarounds, some sites and email servers may become unreachable.