Not the way it works.
You should know how, what, why it was created, what problem it was created to solve, what the downsides and drawbacks are, and so on.
Shows you have domain knowledge, implementation and troubleshooting experience. Shows you've pushed the limits or at least thought about the limits of what something was designed to do.
Dude asks about a protocol. Tell him the history of it, what problem it solves, alternatives, where it gets sticky. How it works in depth, how it works in Linux vs. Windows, who created it, and so on.
You ask me about TCP, you'll get 10 minutes on the history, going all the way back to Vint Cerf (who used to be a co-worker).
You make them stop you from talking. You should be answering five questions to the one they ask.
Depends.
If it's something out of your domain niche that you don't work with frequently then not knowing isn't a big deal. It's so much to learn in tech. I rather someone tell me what they don't know then try to lie and it sounds bad.
Sometimes an interviewer will keep asking you questions until you can't answer something to see what you don't know.
If the interviewer was biased and didn't want to hire you in the first place then they will use that against you as an excuse.