Nslookup (Name System Look Up) is a tool for querying a name server to obtain information about domain or a host and this diagnose possible DNS configuration problems.Invoked without arguments, the nslookup displays the name and IP address of primary name server and displays a command prompt for the query. Simple type a domain at the prompt to display its characteristics. It is also possible to request information about a host by specifying its name after the nslookup command:
Nslookup host.name
By default, the nslookup command queries are primary name server configured on the machine. It is however possible to query a specific name server by specifying it after the command preceded by a "–"sign:
Nslookup host.name -server.name
You can change the query mode of the nslookup command with the set clause: