NSLOOKUP is a Unix service that can display information about the Domain Name System (DNS [RFC1034, RFC1035]).
The purpose of DNS is to map domain names to IP addresses and vice versa.
The online service on this page can be used to query a specific name server or our default name server. Each domain is managed on a primary domain name server responsible for the domain's zone data. Secondary DNS servers map the state of the primary server for security.
If a request can not be answered, NSLOOKUP responds with "NXDOMAIN". Either the queried DNS server is not available or the domain does not exist on the DNS.
To resolve an IP address via reverse lookup (find a domain name based on the IP address), use the PTR query type instead of ANY. However, such a reverse lookup request will only work if the domain owner has deposited a PTR entry in the DNS for this IP address.