Understanding Azure DNS: Simplifying Domain Management in Azure Cloud

Introduction

Domain Name System (DNS) can be considered the internet's phone book, where user-friendly domain names such as www.cloudericks.com are translated into numerical IP addresses such as 192.1.1.1 that computers use. If you're new to the concept of DNS, I recommend reading the SecDops blog post on DNS for a comprehensive understanding of DNS. With that foundation, let's explore Azure DNS Zones here.

What is Azure DNS?

Azure DNS is a cloud-based service offered by Microsoft Azure for hosting and managing domain names. It provides a platform for hosting the DNS records associated with our domain names. These records include A, AAAA, CNAME, MX, and NS records. I recommend reading the SecDops blog post on DNS if you are unfamiliar with these DNS record types. 

Understanding Azure DNS Zones

In Azure, a DNS zone is a container that holds DNS records for a specific domain, such as A, AAAA, CNAME, MX, and NS records. Azure DNS Zones provide a flexible and organized way to manage our domain's DNS settings, whether for public-facing websites or private internal applications. 

Types of Azure DNS Zones

Azure DNS offers two primary types of zones: Public DNS Zones and Private DNS Zones.

Public DNS Zones

Public DNS Zones are used for managing the DNS records of domain names that are accessible over the internet. In the Azure public DNS zone for our website, say cloudericks.com, we manage records that are publicly accessible, like the A records pointing to our public web servers and MX records for handling emails associated with our domain. This setup is ideal for internet-facing websites or services we want people to access publicly.

Private DNS Zones

Private DNS Zones are intended for internal network use within Azure Virtual Networks (VNets). They help manage the domain names of internal resources not meant to be accessed publicly. For example, we can have an internal application, say internalapp.corp, accessible only within our corporate network, hosted on Azure. For this, we create a private DNS zone for internalapp.corp, and inside this zone, we add records that help your employees access this application on our intranet. These records are only resolvable within our Azure VNet, ensuring that the application remains secure and inaccessible from the public internet.

Setting Up Azure DNS

Setting up Azure DNS involves specific steps for Public and Private DNS Zones, tailored to their respective use cases.

For Public DNS Zones

1. Create a Public DNS Zone: Start by creating a DNS zone in Azure for our public domain, such as www.cloudericks.com.

2. Add DNS Records: Populate this zone with necessary DNS records:

   • A and AAAA Records: For IP addresses.
   • CNAME Records: For domain aliases.
   • MX Records: For email services.
   • Other Records: As needed for your domain's functionality.

3. Configure Name Servers in Domain Registrar: Azure will provide name servers for our DNS zone. Update these name servers in our domain registrar’s settings. This step directs our domain’s DNS queries to Azure, making our domain and its services accessible over the internet.

For Private DNS Zones

1. Create a Private DNS Zone: Create a DNS zone within Azure for our internal domain, like internal.yourcompany.net. This zone is used for our Azure Virtual Network (VNet).

2. Add DNS Records: Just like with public zones, add DNS records such as A, AAAA, and CNAME records, but these will be relevant to our internal network services.

3. Associate with Azure VNet: Instead of updating name servers externally, link this Private DNS Zone to one or more of our Azure VNets. This ensures that DNS queries within our VNet are resolved using the Private DNS Zone, keeping the internal domain names secure and isolated from the public internet.

Benefits of Azure DNS

• Global Reach: Leverage Azure's vast global infrastructure for high availability and low latency.
• Security: Azure ensures secure and protected DNS queries.
• Integration: Easily integrates with other Azure services for a cohesive cloud experience.

Common Questions

Q: Is Azure DNS different from traditional DNS hosting?

A: The basic principles are the same, but Azure DNS brings the advantages of cloud scalability, security, and integration with Azure services.

Q: Can I use Azure DNS without transferring my domain to Azure?

A: Yes, you only need to point your domain's name server records to Azure DNS.

Q: Are both public and private zones necessary?

A: It depends on your needs. Public zones are for internet-facing services, while private zones are used within Azure for internal networking.

Conclusion

Azure DNS Zones are an essential part of managing your online presence and internal network services within the Azure ecosystem. With Azure DNS, you're not just organizing domain names; you're leveraging a powerful, scalable, and secure cloud infrastructure to ensure your services are always reachable and reliable. So, dive in and discover how Azure DNS can elevate your internet and intranet experiences!