The DNS protocol has been around for decades and is a stable and reliable protocol. Even so, DNS does occasionally have problems. These problems might stem from a loss of connectivity, an invalid DNS record, or a number of other issues. When a DNS server doesn’t behave in the way that it is expected to, many people turn to the PING command for help. PING is a great tool for DNS server diagnosis, and I tend to use it quite frequently myself. However, sometimes PING just doesn’t give you enough information about the problem at hand. When you need more information about a DNS problem than what PING provides you with, you can always turn to the NSLOOKUP command. NSLOOKUP is a built in DNS diagnostic utility that’s available to both Windows and UNIX Administrators. In this article, I will show you how to use NSLOOKUP.