What is DNS?
The Domain Name System (DNS) acts as a directory for the digital world. It translates human-friendly domain names, such as www.rackzar.com, into machine-readable IP addresses. Although we use domain names to interact with websites, computers communicate through numerical IP addresses. DNS bridges this gap, ensuring that our online experiences are seamless and efficient.
How DNS Works
To understand how DNS works, let’s break down the process that occurs when you enter a website address into your browser. This process can be divided into several key steps
- The process of accessing a website begins when you, the user, enter a domain name (e.g., www.rackzar.com ) into your browser’s address bar.
- Your device then contacts a local DNS resolver, which is usually provided by your Internet Service Provider (ISP). This resolver acts as your digital tour guide, attempting to find the IP address associated with the entered domain.
- If the local resolver doesn’t have the necessary information in its cache, it reaches out to the root DNS servers. These servers are the internet’s master directory, holding information about top-level domains (TLDs) like .com, .org, and more.
- The root servers guide the resolver to the TLD DNS servers, which manage specific domain extensions (e.g., .com). Here, the TLD servers point the way to the authoritative DNS servers responsible for the requested domain.
- The resolver then communicates with the authoritative DNS servers, which are entrusted with the specific information about the domain’s IP address.
- The authoritative DNS servers respond with the required IP address, allowing your device to establish a connection with the web server hosting the website. Once connected, your browser fetches the website content, initiating the process of rendering the webpage on your screen.
DNS Lookup
The process of querying DNS servers to obtain the IP address associated with a given domain name is called a DNS lookup. There are two types of DNS lookup: Recursive and Iterative.
Recursive DNS Lookup
In a recursive lookup, the local DNS resolver takes charge of the entire process on behalf of the user. It sequentially queries the necessary DNS servers, starting from the root and progressing to the authoritative servers.
Iterative DNS Lookup
In an iterative lookup, the DNS resolver interacts with each level of the DNS server, making separate queries at each stage and accumulating the required information to reach the authoritative DNS server.
Six Steps of Opening a Website
Now, let’s break down the six essential steps involved in opening a website
- User Input:
You initiate the process by typing a domain name into your browser’s address bar. - DNS Query:Your device sends a DNS query to the local resolver, seeking the IP address associated with the entered domain.
- Root DNS Servers:
The resolver contacts the root DNS servers to obtain information about the TLD servers. - TLD DNS Servers:
The resolver queries the TLD servers to identify the authoritative DNS servers for the specific domain - Authoritative DNS Servers:
The resolver communicates with the authoritative DNS servers, obtaining the IP address of the requested domain. - Establishing Connection and Website Loading:
Armed with the IP address, your device establishes a connection with the web server hosting the website, and your browser retrieves and renders the webpage.
Conclusion
When you open a website, the Domain Name System (DNS) plays a crucial role. It is responsible for converting the domain name you type into your browser into an IP address that your computer can understand. This process involves six steps, which work together to ensure that you can access the website you want. Understanding how DNS works can help you appreciate the complex communication that happens behind the scenes, making your online experience possible. So, the next time you browse the internet, remember the important role of DNS in bringing websites to your screen.
