What is NSLookup ?

What is Nslookup

Nslookup is a program to query Internet domain name servers. Displays information that can be used to diagnose Domain Name System (DNS) infrastructure.

*Helps find additional IP addresses if authoritative DNS is known from whois.
* MX record reveals the IP of the mail server.
* Both Unix and Windows come with a Nslookup client.
* Third party clients are also available - E.g. Sam Spade

Nslookup employs the domain name delegation method when used on the local domain. For instance, typing 'hr.targetcompany.com' will query for the particular name and if not found, will go one level up to find 'targetcompany.com'. To query a host name outside the domain, a fully qualified domain name (FQDN) must be typed.

The attacker can use dig and host command to obtain more information on UNIX systems.