Yes it's still DNS. _acme-challenge.<arbitrary-ip>.nip.io's role here is to allow tunneling to <arbitrary-ip>:53 through the approved local resolver at 10.214.0.2; without it the direct request to <arbitrary-ip>:53 is dropped.

Someone still has to run that LLM over DNS on an <arbitrary-ip> serving public requests.

> And I'm guessing most people who run something like that don't expose it publicly...

There was a post last week https://news.ycombinator.com/item?id=49771110 that stayed at #1 on front page for hours. If you ignore the LLM framing it's literally an anonymous file host where anyone can upload or download anything, with no or absurdly high file size limits. That should be enough to give any reasonable server admin a heart attack... It's trivial to vibe code shit and throw it on the Internet these days, people who don't understand or care about consequences are doing it by the droves. Go figure.