Domain Name server(DNS) is the most important term on the internet. This is because, without this, we can not access the Internet efficiently. What Do I mean by saying this? Through this article, I will try to explain this term in the simplest way possible.
As per my perception, every person must know about DNS because it helps in daily life. But, we do not know about this, how stupid it sounds! So, today after this article everyone will have deep knowledge about this term.
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What is DNS-An OverView?
The Domain Name Server(DNS) is a server which stores all the data for the internet. These data contain the names, URLs and IP addresses of all the websites. So that if any user writes the name of any particular website on Google, it link’s the user with the IP of that website.
We use DNS because it is difficult for human beings to remember the numbers which IP contains that’s why DNS is used to map name with IP. So when anyone writes name on Google, it redirects them to the mapped IP.
What if DNS Would not exist?
If this wouldn’t exist, then the user has to remember all the IP’s of all the websites which he/she wants to access. Doing this is extensively hectic or perhaps impossible for everyone.
Every website has its own unique IP like 192.168.1.5 (IPv4) or 67D3:7E23:8R33:1::983S:78V2 (IPv6).
So, DNS takes the IP’s and names of websites and map them to store in a table. Whenever a person types a name of any website, it searches in the table for that IP and shows it to the user.
How Does It work?
DNS converts the IP of a website in a user-friendly hostname (such as www.breakingolds.com) which helps the user to remember the website names. It is like a street address for a home (for searching a home we want a street address), without street we cannot reach our home similarly, without knowing the IP we can not reach to the website.
To understand them completely, we have to understand what it does in the backend.
There are four DNS servers which help in loading a webpage.
- DNS Recursor: It acts like Customer Care. It is designed to take a query from the client through the computer through web browsers and satisfy client for DNS query.
- Root Nameserver: It is the first step of finding for IP from the given name by the client. It is like pointing towards Racks in the library.
- TLD Nameserver: Top-level Domain Server check for the IP by the hostname provided by the user. Basically, it searches for the particular Racks for a particular subject.
- Authoritative name server: It checks for the particular IP in a rack. It checks for the particular book in a particular rack and after finding it get back to the Recursor and show the website to the user with the given IP’s.
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Steps in DNS Lookup:
These are the information which is stored locally in the cache in the querying computer or remotely in DNS Infrastructure.
DNS Lookup has 8 steps :
- When user put a query “www.breakingolds.com” in a web browser then after traveling on the internet it is received by the DNS Recursive Resolver.
- Resolver than queries a DNS Root Nameserver.
- Root server than respond to the resolver with Top-level domain (TLS) Server (Such as .com or .net) which store information for domain.
- Than Resolver makes a request to the .com TLD.
- TLD server than respond with the IP of the given hostname.
- Than Recursive Resolver sends the query to the domain name server.
- Lastly IP address of the given hostname return to the Resolver from the name server.
- Than DNS Resolver respond to the web browser with an IP address of the domain request initially.
To Conclude, If it will not be there than 80% of the Internet will be unsubstantiated.