# How DNS Resolution Works

When I first heard about DNS resolution, I honestly felt lost.  
People used words like browser, server, root, TLD, authoritative.  
Everything sounded heavy and confusing.

I thought when I type a website name,  
the browser directly opens that website.

One day, my website did not load.  
Internet was working. Other websites opened fine.  
Someone told me, “This is a DNS issue.”

That moment made me curious.  
I wanted to know what really happens  
when I type a website name in the browser.

Later, I saw a DNS resolution diagram.  
That image changed everything for me.

I understood DNS is not one step.  
It is a **flow**.

In this blog, I will explain DNS resolution  
exactly in the order shown in the image  
and how `dig` helps us see this flow clearly.

---

## 3\. WHAT IS DNS AND WHY NAME RESOLUTION EXISTS

DNS exists because humans and computers work differently.

Humans like names.  
Computers like numbers.

We type:

```plaintext
google.com
```

But the server needs:

```plaintext
IP address (number)
```

DNS is the system that:

* Takes a website name
    
* Finds the correct IP address
    

This process is called **name resolution**.

Without DNS:

* We must remember numbers
    
* Internet becomes very hard to use
    

So DNS exists to make the internet usable for humans.

---

## WHAT IS DNS RESOLUTION

DNS resolution means finding the IP address for a domain name.

This does not happen in one step.  
It happens **layer by layer**.

According to the image, the flow is:

* Browser
    
* Recursive DNS
    
* Root server
    
* TLD server
    
* Authoritative server
    

Each server does **one small job**.  
Together, they solve the problem.

---

## WHAT IS THE `dig` COMMAND AND WHEN IT IS USED

Normally, browsers hide DNS resolution from us.  
We never see which server answered what.

`dig` is a command used to **see DNS answers clearly**.

### Why `dig` is useful

* To understand DNS resolution
    
* To see which server responds
    
* To debug DNS problems
    

### What `dig` gives us

* Name servers
    
* IP addresses
    
* DNS path
    

`dig` does not change DNS.  
It only **asks questions and shows answers**.

---

## DNS RESOLUTION FLOW

![](https://cdn.hashnode.com/res/hashnode/image/upload/v1769750571294/27e5da3c-1443-4824-9421-fb57ff57c127.png align="center")

Now let’s explain the image **step by step**.

---

### STEP 1: BROWSER (chaicode.com)

You type in the browser:

```bash
chaicode.com
```

Important points:

* Browser does not know IP address
    
* Browser only knows the name
    

So the browser says:

> “I need the IP for chaiocode.com”

Browser cannot find it alone.

---

### STEP 2: RECURSIVE DNS SERVER (198.9.9.9)

The browser sends the request to a **Recursive DNS Server**.

This server can be:

* ISP DNS
    
* Google DNS (8.8.8.8)
    
* Quad9 (9.9.9.9)
    

In the image, it is shown as **198.9.9.9**.

Role of recursive DNS:

* Do all the hard work
    
* Talk to other DNS servers
    
* Return final answer to browser
    

Browser waits here.

---

### STEP 3: ROOT NAME SERVERS (`dig . NS`)

#### What this command is

```bash
dig . NS
```

This command asks:

> “Who manages the root of the internet?”

#### What happens in DNS resolution

* Root servers are the **starting point**
    
* They do NOT know website IP
    
* They only know where TLD servers are
    

Image shows:

* 13 root servers
    
* 1600+ copies worldwide
    

Root server replies:

> “Go ask the .com TLD servers”

This is the **first DNS stop**.

---

### STEP 4: TLD NAME SERVERS (`dig com NS`)

#### What this command is

```bash
dig com NS
```

This command asks:

> “Who manages all .com domains?”

#### What happens in DNS resolution

TLD servers handle:

* .com
    
* .org
    
* .in
    

They:

* Do not know IP address
    
* Know which authoritative server owns the domain
    

TLD replies:

> “Ask this authoritative DNS server”

This is the **second DNS stop**.

---

### STEP 5: AUTHORITATIVE NAME SERVERS (`dig google.com NS`)

#### What this command is

```bash
dig google.com NS
```

This command asks:

> “Who is responsible for google.com?”

#### What happens in DNS resolution

Authoritative servers:

* Own the domain
    
* Store real DNS records
    
* Give final answers
    

They know:

* A record (IP)
    
* MX (mail)
    
* CNAME
    
* NS
    

This is the **final decision layer**.

---

### STEP 6: FINAL IP ANSWER (`dig google.com`)

#### What this command is

```bash
dig google.com
```

This command asks:

> “What is the IP address of [google.com](http://google.com)?”

#### Full DNS resolution flow

1. Browser asks recursive DNS
    
2. Recursive DNS asks root server
    
3. Root server points to TLD server
    
4. TLD server points to authoritative server
    
5. Authoritative server gives IP
    
6. Browser connects to website
    

#### Expected output

* IP address (A record)
    
* TTL value
    

This is the **end of DNS resolution**.

---

## VERY IMPORTANT POINT

* Browser talks **only to recursive DNS**
    
* Browser NEVER talks to root or TLD directly
    
* Recursive DNS does all the travelling