Domain Name System (DNS) is a critical component of the internet infrastructure that makes web browsing smooth and user-friendly. It decodes a human-readable domain name into an IP address and makes it enough to remember only a domain name to find a website or send emails online. It is essentially the phonebook of the internet. Below, we will go through the steps of how the DNS works based on our domain.
A user request. The first step is a user request in a browser. When the domain name is entered in your browser, your device starts searching for the IP address related to the domain name.
Checking of local cache. First of all, the IP address of the domain name is being checked in the local cache, which can be separated into:
- Browser cache – usually, browsers have their cache where stored IP recently visited via that browser;
- Router cache – our router can also keep the recently visited IPs in its cache, especially if we try to open the same website often.
Checking the “hosts” file. The operating system uses the “hosts” file to link domains to IP addresses. Using this file, we can manually configure domain name mappings to IP addresses, which is helpful in some cases, like checking a website on a new server before adjusting domain records. It works only if we manually change the device “hosts” file configuration.
A query to DNS Resolver. If the IP address is not found locally or in the “hosts” file, your device contacts a DNS Resolver, usually provided by your internet service provider (ISP). A DNS Resolver can also have a cache, which is being checked first. If the resolver does not find the IP in the cache, it contacts a TLD Server, which knows the addresses of the Top-Level Domain (TLD) nameservers, like “.com”, “.org”, “.net”. To reach our website (Time4VPS.COM), a request will be sent to the TLD Server, which handles domain names ending with “.com”.
A query to the TLD Server. Depending on the domain name extension, the resolver sends the query to the TLD Server to find the authoritative nameserver that stores the IP address for the requested domain name.
Receiving the IP address. The authoritative nameserver returns the IP address to the resolver, which sends it back to your device.
Loading a website in the browser. In this step, your device knows the actual IP address of the server on which the website is located. With that IP address, your browser sends a request to the real server, which processes the request and returns the necessary data to the browser – a website is displayed in the browser.
Why is DNS important?
Easy to remember: Imagine remembering a long string of numbers for every website you want to visit! DNS makes it much easier to navigate the internet.
Flexibility: Website owners can change their server locations without affecting their domain name.
Efficiency: DNS uses a hierarchical system to find the correct IP address quickly, ensuring fast website loading times.