How DNS Works When You Search for a Website

Probably not, but I’m going to explain it anyway! This is where the Domain Name System (DNS) comes in. DNS is quite complex, but I’ll do my best to explain it in the simplest way possible. Since there are many terms and concepts involved, I’ve included a glossary at the end to clarify things. To understand how DNS works, we first need to talk a bit about domain names.

What are Domain Names?

Domain names point to an A record that contains an IP address (more on records later). An IP address is what actually connects you to the server where the website is hosted. The reason we use domain names instead of IP addresses is simple: domain names are easier to remember.

A domain name is made up of three parts and is read from right to left (I’ll explain why later). Let’s use the example example.4bis.nl. The part on the far right, ".nl", is the Top Level Domain (TLD). The middle part, ".4bis", is the Second Level Domain. The third part, “example”, is called a Subdomain. This part is optional.

How Are Domain Names Registered?

Domains are issued by registries that manage specific TLDs. For example, the ".com" TLD is managed by Verisign, while the ".nl" TLD is managed by SIDN. If you want to register a domain, you usually can't go directly to the registry. Instead, you go through a registrar. 4BIS, for instance, is a registrar for the ".nl" TLD, meaning we can register “.nl” domains with SIDN.

What is DNS?

The Domain Name System (DNS) is hierarchical, meaning it works like a tree of Name Servers (NS). A Name Server is a server that forwards requests to other servers. The reason we read domain names from right to left is because that's the order in which the Name Servers are structured. The TLD NS, like ".nl", is at the top of the hierarchy (or at the "root" of the tree), followed by the Second Level Domain and the Subdomain NS. The Second Level Domain and Subdomain share the same Name Server because they are at the same level in the hierarchy.

So, What Happens When You Search for a Website?

Let’s take example.4bis.nl as an example. Here’s a simplified step-by-step breakdown:

• Chrome sends a request to a Root Name Server. The Root NS checks if the TLD you entered is valid.
• If the TLD is valid, the Root NS returns the address of a server that manages that TLD. For ".nl", you’ll be directed to a server that manages the ".nl" domains.
• This TLD server contains a list of Name Servers for the domains under that TLD. It will then direct you to the specific Name Server that manages the "4bis.nl" domain.
• The Name Server for "4bis.nl" contains a DNS zone with records like the A record, which includes the IP address of the server where example.4bis.nl is hosted.
• From this point, depending on how the domain owner has set things up, various actions can occur. For a typical website, this will take you to the hosting server where the webpage is stored.

Glossary

• IP address: A unique address that identifies a location on the internet, similar to how a postal address identifies a house.
• TLD (Top Level Domain): The rightmost part of a domain, such as ".nl" or ".com".
• Second Level Domain: The middle part of a domain. In our example, this is "4bis".
• Subdomain: The leftmost part of a domain, such as "example" in example.4bis.nl.
• NS (Name Server): A server that forwards DNS requests to other servers.
• DNS (Domain Name System): The system that handles domain names and their corresponding IP addresses.

How to Register a Domain

Registering a domain is easy! With the 4BIS domain registration tool, you can quickly check if your desired domain is available. If it is, simply fill out the form and register it!

What is an IP Address?

An IP address is an address assigned to any device connected to a network or the internet. It’s how we uniquely identify a device in the network. You can think of an IP address like a phone number.

There are two versions of IP addresses:

• IPv4 addresses are made up of 32 bits, allowing for approximately 4.29 billion possible addresses. An example of an IPv4 address is 127.0.0.1.
• IPv6 addresses are made up of 128 bits, providing a theoretical maximum of 340 sextillion addresses. An example of an IPv6 address is 2001:db8:85a3:8d3:1319:8a2e:370:7348.

IP stands for Internet Protocol, a fundamental concept of the World Wide Web, established in 1989.

Fun Fact

Did you know that the most expensive domain name ever sold was voice.com, which went for a staggering $30 million?

I hope this makes it clear what happens when you search for a website on Chrome, and how DNS works behind the scenes. It’s fascinating to see how complex the internet truly is!