Domain name system: How does DNS work?

Billions of requests and website views occur every day on the Internet. But few people think about how exactly the process of navigating to a website at the entered address works. One of the key technologies that ensures this process is DNS. In this article, we’ll take a closer look at what DNS is, how it works, and why the domain name system is so important to the Internet.

What is DNS?

Domain Name System is a system that converts domain names into IP addresses. When you enter a web address, such as google.com, in your browser’s address bar, the DNS is responsible for finding the corresponding IP address of that website (e.g. 142.250.186.206). This allows your browser to connect to the site’s server and download its content.

How does the domain name system work?

To understand what DNS is on a deeper level, let’s take a look at the key components of this system:

1. DNS resolver (Client): When you type in a website address, your computer sends a query to the resolver – this is the first step in looking up an IP address.
2. Recursive DNS Server: This server receives a request from the resolver and starts the lookup process. If it already has the information it needs (for example, if someone has recently visited the site), the server returns a response immediately.
3. Root DNS server: If the recursive server does not have the information, it contacts the root server, which points to the domain name system server responsible for top-level domains (for example, .com or .ua).
4. Authoritative DNS Server: This server stores information about a specific domain. It provides the final answer – the IP address that matches the entered domain name.
5. Caching: After receiving a response, your computer and the domain name system server store it in a cache to speed up future access.

Why is the domain name system important?

Now that we understand what DNS is and how it works, it’s important to understand why it is fundamental to the Internet. Without it, users would have to memorize complex numeric IP addresses for each website. The domain name system simplifies this process by allowing the use of familiar domain names.

Protection via DNS

The domain name system can also be a tool for protecting users. Some system services block access to dangerous sites or filter unwanted content. For example, OpenDNS offers additional filtering capabilities, and AdGuard already has a filter for unwanted traffic, including ads.

What to do when the system is down?

Sometimes users may encounter problems with the domain name system, such as:

• DNS server is not responding: This means that the server to which the request is being sent is unavailable. You can try changing the server to an alternative one, for example, from Google or Cloudflare. In this case, it is worth checking the domain records, most likely, the server itself is not available.
• Loading delays: If the DNS servers are slow, it can lead to delays in loading websites. The solution is to choose a faster DNS server.

How to choose the best DNS server?

There are many public DNS servers, including the most popular ones:

• Google (8.8.8.8 and 8.8.4.4): One of the fastest and most reliable options.
• Cloudflare (1.1.1.1 and 1.0.0.1): Known for its privacy and speed.
• OpenDNS (208.67.222.222 and 208.67.220.220): Offers additional filtering and security features.

To choose the best DNS for your Internet connection, you can use special tools that analyze the response speed of servers on your network. Here are some of them:

1. Namebench (Windows, macOS, Linux)
   • Namebench analyzes the available servers in the domain name system and suggests the most optimal options. It also checks your current server and compares it to other public servers.
2. GRC’s DNS Benchmark (Windows)
   • Another popular tool that provides in-depth analysis of the performance of domain name system servers. It also allows you to add your own servers for comparison.
3. DNS Speed Test (online)
   • This is a simple web-based tool that allows you to test the response speed of public domain name system servers right in your browser without having to download software.
4. dig + time (Linux, macOS)
   • This command utility allows you to send requests to DNS servers and measure the response time. To do this, you can use the command dig example.com @DNS_SERVER +time=1 in a terminal.

Conclusion

DNS is one of the most important technologies on the Internet, making it convenient and easy to use. Understanding it will help you not only to grasp how the Internet functions but also to troubleshoot potential connectivity issues.

If you want a faster and more secure browsing experience, pay attention to your server settings for name resolution. Choosing the right service can make your connection more stable, secure, and efficient.