Sometimes, in a large company with undocumented servers, you find an IP Address, and you need to know what server it is. For example, the other day I found a URL of a web service. I pinged the URL, which gives the IP Address. But I needed to know the server name:

nbstat -a xx.xx.xx.xx (where xx.xx.xx.xx is your IP Address)
The -a option “lists the remote machine’s name table give its name).