A Network Administrator command which help diagnosis DNS related issue. However to understand this, you should better to know how DNS works. How to troubleshoot DNS related issue. 1. NSLOOKUP example display "A Record" (IP Adress) of the domain C:\Users\jpudasaini>nslookup jpudasaini.com.np 126.96.36.199 Server: google-public-dns-a.google.com Address: 188.8.131.52 Non-authoritative answer: Name: jpudasaini.com.np Address: 184.108.40.206 A Non-Authoritative Answer is a response from Cache. A DNS server is authoritative for zones actually holds it. The above output shows "A Records" (IP Adress) of the domain " jpudasaini.com.np ". Which is actually query to the public Google DNS. If you don't put DNS after the domain, it will used your default DNS, in my case I have used public DNS. 2. MX Record using -query=mx MX (Mail Exchange) record maps for the specific domain name to verify mail exchaing servers on that domain.