I would fail your interview. I assume interviews are for what I do/don't know. So I honestly say what I don't know, and would not offer to find out. Not right then anyway.

Unless you make it very clear at the outset of the interview that this is exploratory and we will be working with network connectivity and full access to the world's knowledge.

I have sent followups to interviewers on problems that were interesting or deep, but those conversations never turned into anything.