Saturday, March 03, 2012

What is DNS :An Introduction

You type a web address – say www.facebook.com – in the web browser, your computer queries a DNS server to find the corresponding IP address where that site is located and once it has that information, it routes your browser to the correct website.

That is a simplified definition of DNS but, behind the scenes, several parties could get involved as soon as your computer asks for the IP address of a domain name. There’s the Resolving Name Server, the Root Name Server, the TLD Name Server and finally the Authoritative Name Server.

Confused? You don’t have to be as here’s an informative short video that explains the entire DNS workflow in simple English.



Even if you know the basics of DNS, do watch this video and you might end up learning a couple of new concepts around DNS and how it works. The video is courtesy learnDNS.com.

Speaking of DNS, do check our previous tutorials on setting up OpenDNS, Google DNS, learn how to compare two DNS services and know about scenarios when you should not change your DNS server and let it point to your ISP’s default DNS server.

Tip: Find the Name Servers of a Web Domain
If you would like to know about the Authoritative Name Server of any web domain, the one that will most definitely know the location of the IP address of that domain, follow these steps.

Open the command prompt windows by typing CMD in the Windows Run box.
On the command prompt, type NSLOOKUP and hit Enter.
Now type set querytype=soa without the quotes and hit Enter. Sentence case matters and there should be no extra spaces.
Finally type any domain name and in the results, the primary name server is the authoritative name server of that domain.