There are questions that get asked, from time to time, whose answers are fundamental and blindingly obvious to anyone with a reasonable amount of knowledge about the topic being considered, such as this one:

http://serverfault.com/questions/593204/using-dhcp-is-it-possible-to-obtain-an-ip-address-mac-address-for-a-cluster

These questions are easy to answer, and assuming the asker is willing to learn, provide substantial value to the person asking as well as to anyone trying to learn how things all get put together later.  **The answers will explain a fundamental concept.**

On the other hand, they might also conflict with the broken windows theory, and could often be answered in a moment's researching the topic.

Is it really appropriate to close these questions?  Or, is it sufficient to simply downvote them but allow them an answer?  Or should we not even downvote them?