Ah, but if you didn't know something about netstat or sar, you wouldn't be applying for a tool development job in a unix shop, would you? My point is that it's better to ask about the application of the skill than the syntactic details of the tool itself. If you were hiring a carpenter, you'd ask about how they would build different things, not the design of different types of hammers. Obviously, if you're applying for a postition in a Windows-based company or a development position where networking isn't an issue, the question would be different. The concept, however, remains valid.
"What do I want? I'm an American. I want more."