Michael McNamara comments on his blog:
I get quite a few emails and and private messages that contain the phrase above, “Network is down! Please help!”. In the vast majority of cases it usually turns out that the problem is self inflicted. Here are a few simple steps that I strongly recommend you look at if it’s your responsibility to manage the network. These features will help mitigate some serious operational issues from spoiling your day.
A few simple things to check when the network decides to go out to lunch. If these are all good, it’s time to start calling support. But at least you’ll have your bases covered.
Read more at: Network is down! Please help!