A simpler type of problem localization becomes really important when someone runs into your office gibbering and screaming that the network is down. The very best thing you can do in this circumstance is to keep your cool and try to get some coherent information from a very upset person. After all, you’re using divide and conquer; all will be well.
First of all, how do you know when the network is down? Is it really down—that is, non-functional—is it slow, or is an application acting funny? If it is truly non-functional, is it a physical network problem or a server or router problem? What part of the infrastructure is affected?
Sure, the person in your office has no idea. So let’s get simpler.
You’ll probably start by asking ...