What is DNS ?

DNS stands for Domain name system it is nothing but like the phone number directory, you store the phone number of your friends, family members in your mobile phone and give that number a name for example if your friend’s name is John then you will save John’s phone number as John in your phone directory of mobile and then whenevey you want to call John you will search for the John not for the John’s phone number in phone directory you have no need to remember the phone number of John, you can give a name to phone numbers, DNS system exactly works like this You can take an analogy with this phone book example, DNSis a Phone book and friend’s number is IP addres of the server you give a name to the IP address of the server and store that name in DNSwith the IP address so that you don’t need to remeber the IP address of any server you can call the server by it’s name only. We will understand everything about the DNSin this article if you want to know how DNSworks in detail then you are at the right place.

There are so many layers exist so many terminologies and tech jargens used but don’t worry you after reading this article you will be able to explain about the DNSto anyone

DNS Client -

DNS client is the local DNS system which is preinstalled in our machine DNS client also known sa DNS resolver as it’s name says the work of DNS resolver resolves the IP address of the domain name now what is domain name domain name is nothing but the name of the website for example www.google.com DNS client of DNS resolver finds the IP address of that requested domain as I told you DNS client is localy installed in machine or computer DNS client also caches the IP address of the websites. If you want to connect to any server the you have to know the IP address of that perticular machine or server, when you write the domain name of any website, browser search for the IP address of which requested domain is pointing in DNS client, if browser successfully finds the IP address in DNS client then browser redirects you to the server.

DNS root servers-

DNS root server is the server situated in remote location, in the whole world 13 DNS root servers exist we are going to see the need of DNS root server, We have talked about the DNS client previously that how DNS client work but wait, what if the IP address of the rquested domain is not available in the DNS client the so how you will react to the server, to solve this problem DNS root servers comes in the picture, whenever you request for any website in browser the browser search for the IP addres of the requested domain name in DNS client but if the browser is unsuccessful to resolve or find the IP address then browser will ask to the DNS root server for the IP address of the requested domain name, but wait here domain root server does not give you the IP address of the requested domain it gives the IP address of the TDL server.

TLD servers-

TLD stands for Top Level Domain server. Whenever you request for any domain name browser will search for the IP address in the DNS client and id brouser is unsuccessful to resolve the IP address of the requested domain name the request will refer to the DNS root server, as I have told previously that the domain root server doen not give the IP addtess of the domain name but it gives the IP address of the TLD servers. Domain root server checks for the subdomain of the requestd domain name now what is this subdomain, if we request for the domain name www.google.com here .com is the subdomain, DNS root server search for the IP address of the TLD server to which the subdomain of requested domain name belongs, for example if the sub domain of the requested domain is .com then DNS root server will return the IP address of .com TLD server and the the requested domain will be transfered to that TLD server and then TLD server will return the IP address of the ANS.

ANS (Authoritative name server)-

As I have told there are so many layesr and tec jargens in this this filed ANS is an another tech jargen. ANS stands for Authoritative name server in TLD server we have seen that after passing the requested domain name to the TLD server, TLD servers retrns the IP address of the ANS. ANS is nothing but the domain name providers like godaddy, bigrocks etc. after passing the request to TLS server it returns the IP address of the ANS server from where the requesten domain name was bought, and after find the ANS server requested domain name is transfered to the ANS and the ANS returns the IP address fo the requested website or server to the browser and then browser redirects you to the website.

We have two ways to complect the above process to get Ip address of requested domain

Recursive
Iterative

Domain name system (DNS)