Azure DNS

Natasha Ong
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4 min read

In a nutshell:

DNS is like a phone book for the internet, translating human-friendly domain names, like "," into IP addresses (like
DNS is the reason why computers know to take us to the right websites! For example, taking us to "" when we type that into our browser.
Azure DNS is your service for managing domain names and DNS records in the cloud.

What is a domain name?

You might be familiar with domain names already, because they're the names of websites!

For example, is a domain name, and is a domain name.

Domain names are addresses that lets people access websites and online services. Otherwise, your computer wouldn't know what website to take you to!

Wait, but what about IP addresses?

Previously, we learnt that an IP address is a unique label assigned to every device that connects to a network. Hmm, well websites are not physical devices, so why would they have IP addresses?

It might not be super obvious straight away, but websites and online services are hosted on servers - this gives them a physical presence somewhere!

Every server in the world has an IP address that identifies their location on the internet. When you access a website by entering its domain name (e.g., into your web browser, the domain name gets translated into the IP address of the web server hosting that website. Your computer then communicates with that IP address to retrieve the web page.

How does the domain get translated into IP addresses?

Domain names on the internet are organised in a structured way called the Domain Name System (DNS). Think of it as an address book for the internet.

It links domain names to the actual numeric IP addresses that computers use to find them online. This system is essential for the internet to work properly - and DNS is a really important concept to understand for the service we're learning today!

Azure DNS

Azure DNS is a hosting* service for DNS domains.

*Hosting, in the context of DNS domains, means a company or service (in this case, it's Azure) provides a place on the internet to store the information associated with your domain name. This information typically includes records that specify where your website or online services are located, such as the IP address of your web server. Hosting companies manage and maintain the servers and infrastructure needed to make your domain accessible to users on the internet. When someone types your domain name into a web browser, they are directed to the correct location where your website is stored because it's being well hosted.

By using Azure DNS, you can manage your domain names and the associated DNS records* effortlessly. What's great about it is that you can use the same credentials, tools, and billing as your other Azure services, which simplifies the entire process.

*DNS records are the pieces of information in DNS that says 'x domain name = y IP address". They are like rules that tell the DNS system how to resolve and direct requests for your domain.

Benefits of Azure DNS

1. Reliability and performance

  • DNS domains hosted in Azure DNS are connected to Azure's global network of DNS name servers. This means your DNS records are stored in multiple locations for extra safety, across a resilient and highly available infrastructure.
  • Azure DNS uses a technology called anycast networking, which means every DNS query (i.e. everything your computer asks where a website is located) is answered by the nearest available DNS server. This approach results in speedy performance and high availability for your domain.

2. Security

Azure DNS is built on Azure Resource Manager (ARM), which comes with a set of features that are crucial for maintaining the integrity of your DNS services. We'll dive into the security features in ARM another day, but as a little teaser, these features include:

  • Azure role-based access control (Azure RBAC): You can make sure only authorised individuals can make changes. You'll learn more about RBAC in another module!
  • Activity logs: These logs allow you to monitor how users in your organisation modify resources and track down errors during troubleshooting.
  • Resource locking: You can prevent accidental deletions or changes by other users in your organisation. Once again, hang tight - you'll learn heaps more about resource locking later in the course!

3. Ease of use

Azure DNS can handle DNS records for both Azure resources and external resources too.

Since Azure DNS is part of the Azure ecosystem, you can manage your domains and records using the Azure portal, Azure PowerShell or Azure CLI (you'll learn about these two later on too). If you have applications that require automated DNS management, Azure DNS offers a REST API and SDKs* for integration.

*SDKs (Software Development Kits) are like toolkits for software developers. They include ready-made code, instructions, and tools to help them build applications more easily. It's a bit like having a set of Lego pieces and a manual to construct something without starting from scratch.

4. Customisable virtual networks with private domains

Azure DNS also supports private DNS domains. Private DNS domains are hidden website addresses that only certain people or computers can access. This is handy for companies that want to keep parts of their network private!

This feature allows you to use your own custom domain names within your private virtual networks, rather than being restricted to the default Azure-provided names. This flexibility is valuable for businesses that want to maintain their brand and naming conventions.

5. Alias records

Another handy feature is the support for alias record sets.

Alias record sets let you refer to an Azure resource, like a public IP address, a Traffic Manager profile*, or a Content Delivery Network (CDN) endpoint**.

*A Traffic Manager profile is like a traffic director for websites. It helps spread internet traffic across different places, so if one isn't working well, your request goes to another one that's up and running. It's like having multiple cash registers at a store to make sure you get checked out quickly.
**A Content Delivery Network (CDN) endpoint is like a fast delivery person for internet content. It's a specific place where website content is stored, making it quicker for your computer to get things like pictures or videos. It's a bit like ordering a pizza from the closest restaurant to get it faster.

The magic happens when the IP address of the underlying resource changes - Azure DNS will automatically update the alias record set. This means your alias record always points to the right service instance, so your users can access your resources without disruptions.

What Azure DNS can't do

You can't use Azure DNS to buy a domain name. To acquire a domain name, you'll need to go through services like App Service domains or third-party domain name registrars. Once you've secured your domain, you can host it in Azure DNS.

Final note: DNS is not just for websites!

  • For websites, DNS ensures that when you type a domain name into your browser, it knows which IP address to contact for that website.
  • DNS is also vital for other resources, such as email servers, cloud services, remote desktop connections, and more.
  • It's essentially the internet's phonebook, helping your computer find the right destination, whether that's a website, an email server, or another online service.
  • Without DNS, the internet as we know it wouldn't function properly.