What is DNS? How the DNS System Works on the Internet

When you type a website name into your browser, what happens to connect you to the correct address? Few people realize that behind this simple action is a complex system called DNS. Without DNS, the internet would be chaotic and unable to function as expected. So, what is DNS, and how does it work? Let’s explore these questions in the article below.

What is DNS?

DNS stands for Domain Name System, a system that allows you to access websites without memorizing long and complicated strings of numbers known as IP addresses.

Simply put, DNS is like an Internet phone book where you just have to remember domain name (like google.com), instead of having to remember numbers IP address (for example, 172.217.11.46) to access that website.

Without DNS, instead of typing a website name, you would have to remember a series of numeric addresses. This may not be possible for the millions of websites out there.

The Important Role of DNS in the Internet

DNS plays a crucial role in the operation of the Internet, ensuring seamless functionality. Often referred to as a “navigation system”, DNS helps identify and redirect users to the correct website they request.

• Easy access to websites: Instead of remembering a string of numbers, users only need to recall the domain name, while DNS resolves it into the corresponding IP address.
• Support for online services: Online services like email delivery and server connections rely on accurate domain name resolution.
• Network stability: DNS ensures the Internet runs smoothly by routing every domain name request to the correct IP address.

DNS System Structure

The DNS system is organized in a hierarchical structure, consisting of various servers and components that work together to resolve domain names into IP addresses.

• DNS Resolver: This server receives a user’s request and initiates the query process to find the IP address corresponding to the domain name.
• Root DNS Server: At the highest level of the DNS hierarchy, it redirects requests to servers managing top-level domains (TLDs).
• Top-Level Domain (TLD) DNS Server: These servers manage top-level domains, such as .com, .net, or .vn, and direct requests to servers containing domain-specific information.
• Authoritative DNS Server: This server stores the exact DNS records for the requested domain name and provides the official IP address needed to access the website.

How DNS System Works

The DNS system follows a structured process to resolve domain names into IP addresses. While this process is complex, it is highly efficient. When you type a domain name into your browser and press Enter, the steps are as follows:

1. Browser sends a request to the DNS Resolver: The browser queries the DNS Resolver to check if the domain name is in its cache. If found, it immediately returns the result.
2. Query to the Root DNS Server: If the domain name is not in the cache, the DNS Resolver sends a request to the Root DNS Server to identify the server responsible for the top-level domain (TLD) of the requested domain.
3. TLD DNS Server response: The Root DNS Server directs the request to the TLD DNS Server, which manages information about domains such as .com, .org, or .net.
4. Authoritative DNS Server response: The TLD DNS Server forwards the request to the Authoritative DNS Server, which stores the exact DNS records for the requested domain name.
5. Returns the IP address: The DNS Resolver receives the IP address from the Authoritative DNS Server and sends it back to the browser, allowing you to access the website.

This entire process takes only a few milliseconds, ensuring seamless and fast web browsing.

Types of DNS Records You Need to Know

In the DNS system, all information about domain names and IP addresses is stored as a DNS record. Each DNS record contains specific details about a domain, enabling the resolution and connection process. For example, a record might map a domain name to a server’s IP address or identify the server responsible for handling email for the domain.

DNS records come in various types, each serving a distinct purpose to ensure the DNS system operates efficiently and quickly. Here are the most common types of DNS records:

1. A Record: The most common type of DNS record, used to map a domain name to an IP address, allowing the browser to connect to the correct server.
2. MX Record: This record determines which server handles email for the domain, ensuring proper email delivery.
3. CNAME Record: Allows one domain name to redirect to another. This helps multiple domain names point to the same IP address.
4. NS Record: Specifies the DNS server responsible for handling queries for a particular domain.

How to Change and Configure DNS on Windows Computer

If you want to improve internet speed or enhance security while browsing, changing the DNS settings on your computer is a useful option. Follow the instructions below to easily change and configure DNS on Windows:

Step 1: Open Network Settings

• Right-click the network icon in the lower-right corner of the screen and select Open Network & Internet settings.
• Click Change adapter options.

Step 2: Select Network Connection

• Right-click the network connection (Wi-Fi or Ethernet) you are using and select Properties.
• Choose Internet Protocol Version 4 (TCP/IPv4) and click Properties.

Step 3: Enter DNS Address

• Select Use the following DNS server addresses.
• Enter a DNS address:
  • Google DNS: 8.8.8.8 and 8.8.4.4
  • Cloudflare DNS: 1.1.1.1 and 1.0.0.1
• Click OK to save your changes.

Step 4: Check the Connection

• After saving, test the connection by opening a browser or using the command ipconfig /all in Command Prompt.

Compare Public DNS and Private DNS

DNS can be categorized into two main types: Public DNS and Private DNS. While both serve the purpose of domain name resolution, they differ in functionality and use cases.

1. What is Public DNS?

Public DNS are DNS services that anyone can use. For example, Google DNS (8.8.8.8) and Cloudflare DNS (1.1.1.1) are two popular services used by many people because of their high speed and reliability.

2. What is Private DNS?

Private DNS are DNS systems set up specifically for an organization or personal network. This provides greater control and higher security, commonly used in enterprise internal networks.

3. Advantages and Disadvantages of Public and Private DNS

• Public DNS: The main advantage is that it is easy to use, fast, and suitable for individual users. The downside is the lack of advanced security.
• Private DNS: The advantage is better security and complete control over the DNS system. However, it requires more complex configuration and is often more expensive.

How To Enhance DNS Security

DNS is a vulnerable target, and securing the DNS system is important to ensure the safety of your website and data.

1. Common DNS Security Issues

DNS Spoofing: Attackers alter the IP address in the DNS system to redirect users to fake websites.

DNS Hijacking: Hackers take control of your DNS server to carry out illegal activities.

2. How to Protect Your DNS System

• Use DNSSEC: This security solution validates the accuracy of DNS records and prevents spoofing attacks.
• Secure DNS Servers: Ensure your DNS servers are regularly updated and protected with strong network security measures..

Effect of DNS on Website Loading Speed

DNS is not just responsible for domain name resolution; it also directly impacts a website’s page loading speed.

1. Why Does DNS Speed ​​Affect Page Load Time?

When DNS resolution is slow, the time required to map a domain name to an IP address increases, causing users to wait longer for a website to load. This is particularly noticeable when using slow or unstable DNS services.

2. How to Improve DNS Resolution Speed

• Use faster DNS services: Google DNS and Cloudflare DNS are popular choices known for their speed and reliability.
• Leverage DNS caching: Utilize your computer’s DNS caching to reduce domain name resolution time for frequently visited websites.

Popular DNS Services Around the World

There are many public DNS services globally recognized for their speed, reliability, and security. Below are some popular DNS services you can use:

1. Google DNS

Google DNS (8.8.8.8 and 8.8.4.4) is renowned for its fast speed, stability, and ease of configuration, making it one of the most widely used DNS services worldwide.

2. Cloudflare DNS

Cloudflare DNS (1.1.1.1 and 1.0.0.1) offers exceptional speed and robust security, protecting users from cyber threats while ensuring privacy by not collecting personal data.

3. OpenDNS

OpenDNS (208.67.222.222 and 208.67.220.220) provides fast and secure DNS services with advanced malicious content filtering, making it suitable for both personal and business use.

4. Quad9

Quad9 (9.9.9.9) is distinguished by its security features, automatically blocking harmful websites to ensure high safety while browsing the Internet.

5. Comodo Secure DNS

Convenient Secure DNS (8.26.56.26 and 8.20.247.20) delivers fast DNS services along with protection against cyber attacks like phishing and malware.

Conclusion

DNS is an essential component of web browsing and network management. Understanding what DNS is, how the DNS system works, and addressing issues related to security and speed will empower you to manage your system effectively. We hope this article has provided valuable insights into the DNS system, giving you a comprehensive understanding.