To be honest, there's some times when it's useful to know how ethernet works. They're few and far between, but it you don't know when it happens, you're lost.

This is true for all kinds of technical stuff, of course. However, my feeling is that employers should not be looking for people who know every piece of information as much as people who can easily obtain and understand whatever information is lacking and solve problems (in other words: tenacious workers who have a good sense of intuition). I've met tons of technical people who can answer all the questions, but get them in front of some trouble-shooting problem and they're hosed. Of course the flip side to all this is that if I'd known more about J2EE, Oracle, PL/SQL, JSP, etc. I would have spared this community a lot of questions! The best combination, of course, is knowledge and intuition, but I'll take intuition over knowledge if it’s one or the other because knowledge can be obtained.