DNS resolution: What happens when you access a website?
Thanks to DNS resolution, we don’t even think about what is happening when we click to visit a particular website. It is actually a complete process running behind the scene. It truly happens so fast, and because of it, we are not required to remember and type the difficult IP addresses. Instead, we memorize just the simple domain names, and we can easily connect to our favorite website. So, let’s explain a little bit more about this interesting process!
What does DNS resolution mean?
DNS resolution is a process that is triggered every time you want to connect to a website. After you type the domain name into your browser, it should be translated into machine understandable language. They communicate through numbers. For that reason, each domain name has to be translated into its corresponding IP address.
In some cases, a domain could have only one IP address, but it could have several IP addresses in other cases. For instance, one of them could be IPv4 and the other one IPv6. The DNS resolution will request both of them. Yet, it is enough for the user to get just one of these addresses, and it will be able to reach the particular website.
Why do we need it?
The process of quick and easy translation becomes necessary long ago. Before the creation of DNS, each IP address was stored in a Host file, which was manually updated. Yet eventually, the devices that wanted to connect to the Internet increased into a higher number that it was not practical anymore to store the addresses that way.
So, the Domain Name System was developed, including the DNS resolution process. Thanks to it, the Internet nowadays is simple and easy to use. We are not required to remember the IP addresses but only the domain names.
What is the process behind the DNS resolution?
There are several steps in which the DNS resolution is completed. It is initiated when a user desires to connect to a website, a domain name for the first time.
- You write a domain name inside the browser. That is how the DNS query is made. After that starts a process for searching the analogous IP address – DNS lookup.
- The DNS recursive server receives the query, and it checks if the IP address is still available in its cache memory. If it is the first time requesting that specific domain, the answer won’t be there. So, the DNS recursive server is going to look for the address in the rest of the servers – Root, TLD, and finally, the authoritative DNS server.
- The Root server is on the top of the DNS hierarchy, which is the first stop of the lookup. It gives information and directs to the responsible Top Level Domain (TLD) server, for instance, .com, .info, etc.
- The TLD server is going to provide information about which is the responsible nameserver for that specific domain name.
- Next, the DNS recursive server can ask the authoritative DNS server for the IP address of the domain.
- After receiving the answer, the Recursive DNS server can return to your browser with the needed data to access the website. Moreover, it will keep the IP address in its cache memory if you want to explore the site later.
- Finally, the browser loads the website you have typed.
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So, now you know what process stands behind the DNS resolution. An how fast it actually happens!