Since updating to Big Sur i've had this strange error, that i've been debugging to try and help out a bit with this error i'm getting with local DNS.
I use Docker/Kubernetes locally to run a particular application at a series of particular domains via the browser. I do this by adding local IPs to the Network/(Adapter)/DNS/DNS Servers and having the last item be 220.127.116.11 so it would pick up the local docker container DNS first and fall back etc.
Upon upgrading (from Catalina) I noticed that these were not working.
so did the normal things of flushing DNS, clearing cache etc. Then it would work, but only for a small period of time after a DNS flush using:
Code Block sudo killall -HUP mDNSResponder
So i would have a small window where i could access these, and once on the domain it seemed to be fine and would stick the DNS to the correct DNS Server IP, however all other local domains would fail, but if i run the flush DNS command again it would allow me onto the failed domain again.
I naturally debugged all my containers and they are working as intended as seen via the fact they're responding correctly some of the time, but as it requires a DNS flush it seems like there is more of an issue there.
Has anyone else had any issues using DNS servers, and does anyone have an advice for maybe debugging this further?