Greetings everybody - this is my first-ever post on this forum so hello-and-how-are-you! Also, apologies in advance for the long, wordy post.
I've been happily running ZorinOS in various capacities since version 12 and until now have not encountered any trouble I could not easily figure out on my own or else invent a workaround. However, recently I've run into trouble with DNS that I've not been able to push past.
Currently I'm running Zorin 16.1 on several machines on my network, including one that I've been trying to configure as a homeserver and DNS sinkhole. I've managed to successfully configure the machine to run Pi-Hole, Unbound, and Tailscale so as to be able to perform name resolution, DNS filtering, and upstream DNS for all the machines on my network, and I've been able to get these functions working remotely via Tailscale. I'm also able to access files via FileBrowser and can manage the machine with Cockpit, all over the tailnet. All of these functions involve DNS in one way or another and they all work just about perfectly.
However, I keep running into a strange situation: the precise moment I try to install a Docker container, name resolution breaks on the local machine only. All of the network stuff still functions. The Pi-hole keeps Pi-holing, Filebrowser continues working just as before over the Tailnet, upstream DNS duty via Unbound still happens for all the machines on my network, and I can ping the homeserver using its hostname from inside my network as well as out in the world. However, the machine hosting these services cannot do name resolution for itself, meaning I can't update the OS, install software or update packages, or even ping another machine on the local network or the internet using target machine's domain or hostname. I can ping anything I want so long as I have the IP address, but name resolution is right out.
I've encountered this exact breakdown two times previously and each time it has happened I have given up trying to solve the problem on my own and resorted to re-installing everything from scratch. Each time the problem manifests immediately after running Docker.
I'd like to know how to fix this, because there are Docker apps I'd like to be running (namely Quanta and emulatorjs) but not at the expense of breaking my server.
I will show technical infos and terminal output in subsequent posts in this thread, but i wanted to put this out there as a preamble just to see if anyone has encountered anything similar, and to verify that I'm communicating clearly.
Any thoughts as to what might be going on before the copy-pasting begins?
Thanks in advance!