What is DNS and why is it needed? What is the importance of DNS on the Internet?

If you’ve been using the internet for a long time, you’ve probably heard of a name, DNS. Its full name is Domain Name System. This DNS can be said to be one of the primary and essential components of the Internet. This DNS basically lets your browser know exactly which website or server you need to go.

What is the main function of this DNS and why is it needed? This is what I will discuss today.

DNS


When you visit a website, of course, you have to type the URL of the website in the browser or simply the address of the website. Eg Google.com or Techubs.net. However, when you type the address of the website in the browser and press enter, but your browser or your internet does not find the desired website with the help of that URL. Your browser basically needs to know the IP address of the website you want to visit.

So when you enter the address of a website, your browser basically sends a request to DNS to get the IP address of your desired website. You can call this DNS like a dictionary on the Internet where the IP addresses of web servers are stored.

The first place this DNS request goes is the Recursive Name Server. This name server usually operates your ISP. However, there is no need to use your ISP server only. You can also use public name servers that are operated by different organizations. Such as Google Public DNS or Cloudflare DNS etc.

Recursive Name Server


Now let us know what these name servers do. These public name servers or your ISP name servers will most of the time store the IP address of your desired website. But many times if the IP address of the website is not stored, then basically this request goes to another place which is called root server. These root servers keep a record of the IP addresses of all top-level domains (.com, .net, .org, etc).

It may seem like a small number of servers, but the database of these root servers is much larger than you might think. These root servers basically use physical hardware and data centers around the world to ensure that these requests are always instantly served to everyone.

what is DNS

Then when the IP address behind your desired domain is found, then your request is handed over to the server of the top-level domain you want to access (the server that was extracted with the IP address). Suppose you requested a visit to the Techubs.Net domain.

This recursive name server will then send your request to the domain server at this URL. And from here, your request will be sent to the cloud server where the domain of your desired website is pointing to the nameserver, that is, all the data of the website is hosted on the cloud server so that all the data of that website is served to you from there. And then basically you can access the website.

DNS caching


To save time, both your computer and the recursive name server cache these DNS requests, or simply put them locally on your device, so that your device can know in advance what the IP addresses of the websites you visit and when you next visit that website. When you go to visit, you don’t have to look for a new IP address again.

This is exactly the reason why when you visit a website once and then visit it a second time, the website loads faster than before. This is because, like before, your browser did not have to find the IP address of the website. Because your computer has already saved these IP addresses.

DNS caching

DNS works without any problems in most cases. However, many times if a website you visit changes their IP address or their server, then there may be a problem. It then appears that the current IPT of your desired website does not match the DNS record saved in your cache.

When accessing the website, your browser may show you 404 errors until it can update the DNS records anew. However, it can be fixed with the help of a simple CMD command. In Windows, open the command prompt in administrator mode and enter the ipconfig / flushdns command to clear your DNS cache.

DNS spoofing / DNS cache poisoning


This is basically a hacking method that hackers use to exploit your device for their own benefit. Suppose you somehow inserted some kind of malware into your PC which targeted your DNS cache. This malware will basically edit your DNS cache, change the IP addresses of all the websites you visit, and set the IP of any malicious website they want so that when you visit that website you are redirected to a hacker’s desired website without being taken to that website.

If you ever visit a website that you visit every day and one day you see that you are being redirected to another suspicious website, then you are most likely a victim of DNS spoofing. You should then scan your entire system using a reliable malware scanner as soon as possible. E.g. Malwarebytes.


So this was a simple explanation of what DNS is and what it does. The DNS thing has basically made our internet a lot easier. Otherwise we might have to access every website by typing the IP address. It’s a lot like calling someone by remembering and typing the complete phone number. Anyway, I ended up here like today. I hope you like today’s article. If you have any questions or comments, please let us know in the comments section.

Sabik Al Mahmud

There was a fascination with technology from a very young age, and perhaps that fascination is a little more than other ordinary people. From Nokia's button phones to infinity display bezel-less smartphones, everything is my favorite. Technology has never been more impressive in my life. And writing started with an interest in this technology .....

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