What is DNS | How DNS Works | Types of DNS | Is DNS Necessary
Hi to all here I am going to tell you all about what is DNS and How it works to open a website and whether DNS is necessary or not.
Table of Contents
Introduction about DNS
In the internet computers always identified each others by numbers called IP (Internet Protocol) address, they don not understand human languages.
If computers do not understand human languages, how they load a website when we type it's address in the web browsers URL bar, that the place where DNS comes in.
Suppose we speak English and we want to communicate a person who speaks French, for effective communication we will need a translator, same is the case on the internet too.
Computers or the web browsers understand IP address, and we humans understand all languages say English.
DNS acts as a translators between humans and computers, DNS or Domain name system maintains a table where names are mapped to numbers or more specifically where websites domain names are mapped to their to IP address.
Now when we type google.com in the web browser, DNS translates it to the web browsers languages i.e. IP address, and gives it to the web browser, now web browser understands that we want to access google.com, so it contacts the google servers loads google.com on the computer.
In short DNS acts a phone book of the internet, where computers search with names to get numbers.
How DNS works Internally ?
To understand this we should know what are DNS servers.
Servers are a type of computers which stores different types of files in it.
The Servers that works at once to provide the IP (Internet Protocol) address of the asked website to the browser are known as DNS servers.
Types of DNS Servers?
The four types of DNS servers are as follow:
1. DNS Recursive Resolver or DNS Resolver
2. Root Name Server
3. Top Level Domain or TLD Name Server
4. Authoritative Name Server
DNS Resolver:
DNS resolver is provided by the internet service provider, it connects the web browser of our computer to the DNS name servers.
Root name Servers:
There are 13 sets of root name servers, logically named as letter.root-servers.net, where letter range is from a to m and are operated by 12 different organizations.
Each set has a number of servers placed around the world, and informational page exists for all root name servers and address letter.root-servers.org.
Where letter range is from a to m except g.
For g this is the home page address https://disa.mil/g-root
Details of all root name servers can be found in the website www.root-servers.org
TLD Name Servers:
TLD name servers stores the information, of all domains sharing a common domain extension.
Domains: .com, .net, .in, .edu and more.
For example:
.com TLD name servers stores the information of all websites ending with .com extensions
.net TLD name servers stores the information of all .net websites etc..
Authoritative Name Servers:
It is the last server in the domain name system, it stores the IP address of the requested website.
Authoritative name server for a website can be found with the CMD commands i.e. open CMD and type nslookup, you can see the default server and address and after that you need to enter set query= ns and click enter, then type the domain name, now it shows everything related to the domain you have entered.
DNS Step by Step Process
How a computer loads a website ?
Suppose we type google.com in the web browsers, since web browsers needs IP address, so it forwards to the computers operating system.
Operating systems are configured to forward a query to the DNS resolver, operating systems then contacts the DNS resolver, DNS resolver checks its cache whether it has the IP address of the requested website, if not DNS query is forwarded to the root name servers, this servers checks the extension of the website, whether it is .com, .org, .in, .net etc.. based on the extension the root name serves provides the IP address of the TLD name servers to the DNS resolver, in this case IP address of .com TLD name servers is provided to the DNS resolver, DNS resolver then contacts .com TLD name server which then provides the IP address of the authoritative name server, which should necessarily stored IP address of the requested website.
Finally the authoritative name servers provides the exact IP address of google.com to the DNS resolver, DNS resolver stores this information in it cache for future use and provides the IP address to the computer operating systems, then operating system forward to the web browser, the web browsers contacts the google server and loads the requested website i.e. google.com
But TLD name server knows which authoritative name serves stores the IP address of the requested website, it all begins when we purchase a domain name from a registrar, for example GoDaddy.
In domain registrar webpage we can set authoritative name server that domain should be used, we get the complete details of the authoritative name server, when we purchase the web hosting from hosting provider, once authoritative name servers details are entered in the registrar website, registrar tells the TLD name server managing authority, registry to update the TLD name server with the details of authoritative name server the users has provided.
Now the TLD name server recognizes which authoritative name server will prepare the similar IP (Internet Protocol) address of the asked website.
Is DNS Necessary ?
If we know the dedicated IP address of a website, we can access it, by typing it's IP address in the web browser, in such case DNS will not play any role because we already know the IP address of the website.
How ever as the number of websites increase it becomes difficult to remember the IP addresses.
So, DNS servers eliminate the need for humans to memorize the complex IP address, the only thing we need to memorize is the domain names, which are easy to remember
Conclusion:
I hope that you have understood the information regarding DNS, how it works, types of DNS and Why it is necessary, for more information follow our webpage.
