I was interviewing for a job several years ago and I was asked a Cisco routing question regarding administrative distance. I was thinking about the answer and managed to get it confused with advertised distance, which is related to the EIGRP protocol(Yes, I know the P in EIGRP stands for protocol, but I am considering that not everyone who reads this knows what EIGRP is.). I knew I had messed up, and when I left the interview, it bothered me enough to where I went home and memorized the administrative distance table. To this day, I still know the administrative distance values that Cisco uses for each of the routing protocols it supports. I got the job, but still hate the fact that a trivial thing like AD was missed.
I interviewed a guy this week for a mid-level network engineer slot working for a client of ours. He had already passed the phone interview, which was a basic network trivia screen, and was there for the in person interview. When we spoke on the phone a week earlier, I had asked him about his experience with Spanning Tree, and if he knew about the 3 main types of standards based Spanning Tree. He got “common” and “rapid”, but missed the third one. One of the first things he said to me when the interview began was that he went home that night and realized he had forgot about MSTP. That’s when I told him my AD vs EIGRP AD story. Failure bothered him. I liked that about him. Whether he gets this job or not, I suspect he’ll do fine in the long run.