AZ-800 Administering Windows Server Hybrid Core Infrastructure Exam

Implement and Manage Azure DNS Zones and Record Sets

Azure DNS is a hosting service for DNS domains that provides scalable and high-availability name resolution using Microsoft Azure infrastructure. It integrates with the same APIs, tools, and credentials as other Azure services, allowing consistent management. By using Azure DNS, organizations can reduce complexity and ensure reliable name resolution across on-premises and cloud environments. This service lays the foundation for hybrid DNS solutions that span data centers and Azure virtual networks.

Creating DNS zones is the first step to organizing domain records in Azure DNS. A DNS zone represents a single DNS namespace, such as example.com, and contains a set of record sets that map names to resources. When you create a zone, you specify a unique name within a resource group and can immediately add records like host names or mail exchanges. Understanding apex records and TTL values is critical for proper caching and resolution.

Azure DNS supports all common record types, which you can use to direct traffic, verify domains, and optimize services. The main record types include:

• A: Maps a name to an IPv4 address.
• AAAA: Maps a name to an IPv6 address.
• CNAME: Maps an alias to another canonical name.
• MX, TXT, SRV, NS: Handle email routing, text information, service locations, and name server delegation. You can create or modify record sets using Azure CLI, PowerShell, or the Azure Portal. Assigning multiple values to a single record set allows you to host multiple servers under one name. Carefully selecting the correct record type and value ensures accurate and efficient DNS resolution.

Security in Azure DNS is managed via Azure Resource Manager, offering features to protect zones and record sets from unwanted changes. By applying Role-Based Access Control (RBAC), you can grant specific permissions to users or groups, ensuring that only authorized personnel can make changes. You can also add resource locks to prevent accidental deletion or modification of critical DNS zones. For an extra layer of trust, enable DNSSEC to authenticate DNS responses and guard against tampering.

In hybrid environments, you often need both public and private DNS zones, along with custom forwarding rules. Azure DNS lets you create private zones linked to virtual networks, enabling name resolution between Azure resources and on-premises systems. You can configure conditional forwarding to direct queries for specific domains to on-premises DNS servers. For large organizations, consider zone delegation to distribute management across teams and delegate subdomains. Finally, regularly review TTLs, verify record accuracy, and monitor query metrics to maintain a healthy DNS infrastructure.

Conclusion

In this section, we explored how to implement and manage Azure DNS zones and record sets. We learned how to create DNS zones, define record sets, and understand key terms like TTL and apex records. We reviewed the main record types supported by Azure DNS, including A, AAAA, CNAME, MX, TXT, SRV, and NS, and saw how to use Azure CLI, PowerShell, or the Azure Portal for management. This knowledge helps ensure that DNS resolution is consistent and efficient across your hybrid environment.

Security is a key part of DNS management, and Azure DNS offers features like RBAC, resource locks, and DNSSEC to protect your zones. We also covered hybrid name resolution techniques such as private zones, conditional forwarding, and zone delegation to support seamless connectivity between on-premises and cloud settings. By following best practices like reviewing TTL values, monitoring records, and organizing zones logically, you can maintain a secure and reliable DNS service. These concepts form the foundation for building strong hybrid core infrastructure in Azure.