beyond dot com

I recently bought my first domain for my project MindR (check it out if you haven’t already) and it made me curious about how domains and internet as a whole is made accessible to out browser. The path between typing a URL and seeing a webpage unfold is anything but direct.

First Things First: What a URL Is

Before we explore what happens after you press enter, let’s break down what a URL (Uniform Resource Locator) is all about. Here’s a sample URL:

https://www.google.com/search?q=home

Each part of this URL has a role to play:

1. Scheme (https://): This tells the browser which protocol to use to access the website (like HTTP, HTTPS, WS).

2. Domain (www.google.com): The easy-to-remember name of the website, which will be translated to an IP address in the next steps.

3. Path (/search): This directs the browser to a specific resource or page within the site.

4. Query Parameters (q=home): These are extra pieces of information for the server, like search keywords.

The Secret Sauce: DNS and Why It Matters

When you enter a domain like google.com, your browser actually needs the IP address (some numbers with some dots) of the server hosting Google’s website. Memorizing IP addresses, though, would be a nightmare, which is where DNS (Domain Name System) comes in.

DNS (Domain Name System)
A system that translates domain names (like google.com) into IP addresses (like 142.250.64.78), allowing browsers to connect to websites.

Here’s how DNS process works:

• Browser Checks Cache: It’s less frequent for popular websites to switch domains hence browser caches records for recently visited sites in its internal memory. If it has google.com saved it uses it directly. If not the request continues.

• Operating System and Router Cache : If the browser cache is empty, the request moves to your computer’s operating system and then your router. These also store cached DNS data to speed things up.

• ISP DNS Resolver : If neither browser, OS or router have the IP address the request can go either to the ISP's DNS resolver(default) or to a third-party DNS server like Google’s 8.8.8.8, Cloudflare’s 1.1.1.1, or others, depending on your network settings.

Record At The End Of The Web.

The DNS resolver’s journey involves reaching out to various types of servers, each with its own piece of the puzzle. Let’s dive into each stage of this journey.

1. Root Name Servers: The Internet’s Starting Point

The DNS resolver starts by asking one of the Root Name Servers for guidance. There are 13 unique root name servers in the world, but each has multiple copies distributed globally for reliability and speed. These servers are essentially the “top of the hierarchy” in the DNS system and play a critical role in directing DNS queries to the next appropriate server.

When the DNS resolver asks a root name server where to find google.com, it doesn’t get the IP address for google.com directly. Instead, the root name server responds with the IP address of a Top-Level Domain (TLD) server that handles .com domains.

Root Name Servers
These servers serve as the first checkpoint in DNS resolution, holding records that direct queries to the appropriate TLD servers (such as .com, .org, etc.).

2. Top-Level Domain (TLD) Servers: Narrowing It Down

Now, the resolver has directions to a Top-Level Domain (TLD) Server that manages .com domains. TLD servers are responsible for one “zone” of the internet based on domain suffixes like .com, .org, or .net. Each TLD server knows where to find the IP addresses for domains ending with its specific suffix.

When the DNS resolver contacts the .com TLD server and asks for google.com, the TLD server doesn’t give the IP address directly. Instead, it points the resolver to the next level: the Authoritative Name Server for google.com.

Top-Level Domain (TLD) Servers
These servers store records for each domain suffix (e.g., .com, .org) and can direct DNS queries to the specific authoritative name server for a domain.

3. Authoritative Name Server: The Final Destination

The DNS resolver now arrives at the Authoritative Name Server for google.com. Think of this server as the custodian for the final answer. Each domain on the internet has one or more authoritative name servers responsible for storing the official records, including the IP address associated with that domain.

When the resolver queries the authoritative server for google.com, it finally receives the IP address that Google’s servers use to communicate on the web. This authoritative server is managed by the organization that owns the domain (in this case, Google), and it’s configured to provide the exact IP address needed to establish a connection.

Authoritative Name Server
This server has the definitive IP address for a domain, as configured by the domain owner, and returns this information to the DNS resolver.

Why So Many Steps?

This multi-layered process is essential for managing the scale and security of the internet. With billions of unique domains, having a single server that stores every possible IP address would be inefficient and impossible to maintain. By breaking it down into levels, DNS resolution becomes faster, more secure, and more manageable. Caching along the way ensures that future requests happen even faster, saving time and resources.

Each part of the DNS journey—from the Root Name Servers all the way down to the Authoritative Name Server—contributes to making the internet resilient, efficient.

Types of DNS Records: The Key Pieces of Information

Domains don’t just have IP addresses attached to them; they also hold multiple types of DNS records. Each record type has a unique purpose, guiding requests to specific services or adding extra information. Here’s a rundown of the most common DNS record types and what each one does:

1. A Record (Address Record)

   This is the main record that maps a domain name to an IPv4 address (like 192.168.1.1). When you type in example.com, the A record provides the browser with the IP address of the server hosting the website.

2. AAAA Record (IPv6 Address Record)

   Similar to the A record, but this one maps a domain to an IPv6 address (like 2001:0db8:85a3:0000:0000:8a2e:0370:7334). IPv6 is the newer IP addressing standard designed to accommodate the growing number of devices on the internet.

3. CNAME Record (Canonical Name Record)

   A CNAME record is used to alias one domain name to another. For example, you might set up a CNAME record so blog.example.com points to example.com. It’s commonly used for subdomains or to point to external services.

4. MX Record (Mail Exchange Record)

   This record directs email traffic to the correct mail server for a domain. If you’ve ever set up business email, you may have encountered MX records, which are necessary for receiving emails at addresses like yourname@example.com.

5. NS Record (Name Server Record)

   The NS record identifies which name servers are authoritative for a domain, essentially telling the DNS resolver which server to ask for the domain’s other DNS records.

Wrapping Up

It’s easy to overlook how elegantly DNS holds everything together, making the internet what it is today. By converting billions of hard-to-remember IP addresses into simple names, DNS has made the web navigable, functional, and fast. Its complex yet decentralized structure also keeps the internet resilient, allowing it to handle trillions of requests daily across the world. Personally for me DNS is pure beauty of a software.