When I interview, I start out by asking one or two key questions that help me quickly get to the truth. For instance at one company, when I has hiring NOC folks, I started by asking them to explain traceroute to me.
"Which one? ICMP, UDP or TCP traceroute (to name the usual ones)?"
PS: this is the answer I'd expect from applicants... but this depends on what cluelevel you want/need in your NOC. :-)
It's not the answer I would expect. First of all, the question asked the candidate to "explain" and the answer was not an explanation. In fact, the answer was just the kind of meaningless memory work that CCxx and MSxx certified people are good at. As an interviewer, I don't want short answers like you find in a multiple choice exam. I want some detail that shows that the candidate really does have some understanding of how network protocols work on the inside. Mistakes are OK because I'm not marking the person on their perfection but I'm trying to find out how they think and how they might approach network problems on the job. It's the same reason that I like to ask candidates to tell a story about some past event and how they, personally, dealt with it. If a candidate has had real personal experience of something then they will be able to tell me a story filled with detail. On the other hand, you sometimes get people who can only say "we" did this and "we" did that which leads you to believe that maybe the person was the NOC janitor or something. The best job interview questions are the ones that don't have a right answer. --Michael Dillon