Why is nslookup evil?
Ok . . . technically nslookup is not evil. In fact, if you are working on a problem involving the local system resolver, it is a good tool to use since it uses the resolver in all its glory. However, if you are trying to debug a DNS problem, it is a bad tool for precisely that reason. The ‘host’ program, included with the BIND distribution, is an excellent tool for doing simple lookups, and with the new command line options can be used for more specific queries. For more complex issues, the ‘dig’ program, which is also included with BIND, is the tool to use. It formulates its queries the same way your name server would so you see the same answers that your name server does when asking the same question. The output is quite verbose because it displays (by default) all of the information from the response packet. Learning to understand that information is essential to becoming a proficient DNS Administrator.
