FWIW I’ve had Google recruiters ask me stuff where they don’t understand the answer and the questions are things like “what is the protocol number for ICMP” and “what port does NTP use”. If one doesn’t work with these things very often, they’re very forgettable as they’re so easy to google and find the correct answer to in seconds, and therefore not worth memorizing. No idea if they’re still doing this, but it was like a crappy version of Hacker Jeopardy (#DFIU!). After about 6 months of back and forth with the recruiter and a few interviewers missing interviews, I just gave up and told them I was no longer interested.