I have been using Quad9 for my DNS, setup at the router level, for months without issue. Today, I woke up and the internet wasn’t working, and as the one in the house who self-hosts a couple things on an old laptop and thus tinkers with the router, I was the one my roommates looked at in a panic.
I figured I’d just do a factory reset, and it worked! And then stopped working when I changed the DNS from my ISP’s servers to Quad9’s. I can’t even ping their servers from my home network.
Could my home IP have been banned from Quad9 for some reason? I truly can’t imagine why.
EDIT: Update if anyone cares, it works now. I assume it was a problem somewhere between my network and Quad9’s servers, since I didn’t change any configurations to make it work.
What happens if you run a traceroute to their servers?
It drops after a couple of jumps:
[...] 11 equinix-ashburn.woodynet.net (206.126.236.111) 52.562 ms 63.837 ms 51.576 ms 12 * * * 13 * * * 14 * * * 15 * * * 16 * * * 17 * * * 18 * * * 19 * * * 20 * * * 21 * * * 22 * * * 23 * * * 24 * * * 25 * * * 26 * * * 27 * * * 28 * * * 29 * * * 30 * * *