Not sure if this is the right place.

The last few days I’ve been experiencing a few issues resolving DNS on my home network. Strangely, rebooting the router seemed to fix it for a time. After running into the issue again I decided to investigate further. I’m using a Mikrotik router with my PC wired in with ethernet cable. The router is using DoH to Quad9 (https://dns.quad9.net/dns-query as per their documentation). I’ve also imported root certificates for validation.

As of right now, my desktop cannot resolve dns against 9.9.9.9, however it can resolve dns against 1.1.1.1 and 8.8.8.8.

$ dig @9.9.9.9 reddit.com

;; communications error to 9.9.9.9#53: timed out

Interestingly also cannot curl the DoH URL (also a timeout). I thought maybe Quad9 is having issues so I jumped over to my EC2 instance, and I can dig/curl just fine.

I also turned on debug logging on the router, the logs indicate the same issue my desktop is having (timeout errors, sometimes and SSL handshake error).

My question to you all is, have I missed something in my testing/setup, or is Comcast blocking Quad9?

Additional info:

The mikrotik is the latest firmware (6.49.10). I can switch to CloudFlare DoH on the router and it works fine. I can remove the DoH setting entirely and it works. I’ve got 8.8.8.8 as a static DNS server and the 2 comcast dns servers are dynamic (75.75.75.75 and 75.75.76.76). NTP is setup and the router has the correct date/time/timezone.

As of this writing rebooting the router is no longer temporarily fixing the problem.

Edit:

Thanks u/[email protected] !

Per their post the status page shows issues in my area: https://uptime.quad9.net/