The Domain Name System (DNS) is part of the "dark matter" of the internet. It's hard to observe the DNS directly yet it exerts an obscure, pervasive influence without which everything would fly apart. Because it's so difficult to probe people tend to take it for granted, which I think is a mistake. DNS problems can hurt the speed and reliability of your applications without you even noticing. In this article we'll take a look at the behavior of the DNS and walk through some experiments you can run to gather valuable data about your users' network performance. Read more....