AZ-800 Administering Windows Server Hybrid Core Infrastructure Exam

Configure Conditional Forwarding and Resolver Endpoints

Conditional forwarding in Windows Server DNS lets the DNS server decide where to send queries based on the requested domain. This is essential when you want on-premises systems to resolve Azure Public DNS for internet names or Azure Private DNS for internal resources. By setting up these rules, you ensure seamless hybrid name resolution across your network. Proper forwarding keeps DNS traffic efficient and avoids misrouting. It also lays the foundation for connecting on-premises servers with Azure services.

To enable Azure name resolution within a virtual network, you configure your on-premises DNS servers to forward queries to Azure's recursive resolvers. You often include the special IP 168.63.129.16 in your DNS settings to maintain low-latency and reliable responses. With this IP, Windows Server DNS forwards requests for Azure hostnames directly to Azure's infrastructure. This setup ensures that virtual machines and domain controllers in Azure can resolve both on-premises and Azure names without manual host entries. It also supports scenarios where you use Azure VPN Gateway with custom DNS IPs.

For conditional forwarding, you create rules that target specific domains. These rules might:

• Forward external queries (for example, *.com) to Azure Public DNS
• Send internal zone queries (for example, corp.contoso.local) to Azure Private DNS
• Direct other unknown names to your public internet resolver

By defining these rules, you keep DNS traffic organized and directed to the right resolver. This approach prevents name resolution loops and reduces query latency. It also simplifies management since changes to one DNS server can propagate via forwarding rules.

The Azure DNS Private Resolver is a managed service that sits within your Azure virtual network to automate DNS query handling. It removes the need to deploy and maintain DNS servers on virtual machines in Azure. Instead, you deploy resolver endpoints across one or more subnets, ensuring that DNS queries from both on-premises and Azure resources are resolved consistently. This service is designed for hybrid name resolution scenarios in complex environments. It also offers integrated security features to protect DNS traffic.

By integrating Azure DNS Private Resolver, you gain benefits that include:

• High availability: Always-on DNS service without single points of failure.
• Scalability: Seamlessly handle increased query loads as your network grows.
• Cost savings: Avoid VM provisioning, patching, and management.
• Performance: Reduce query latency by keeping traffic within Azure's backbone.

These capabilities help maintain efficient and secure DNS operations across hybrid infrastructures.

Conclusion

In summary, setting up conditional forwarding on your Windows Server DNS allows you to direct internet-bound queries to Azure Public DNS and internal queries to Azure Private DNS. This ensures that on-premises and Azure-hosted resources can resolve names without extra hops or manual configurations. By tailoring forwarding rules to specific domains, you keep DNS traffic organized and reduce the chance of misrouting. It also centralizes management, making it easier to update or roll back changes across your hybrid environment.

Deploying Azure DNS Private Resolver endpoints extends these capabilities by providing a fully managed, scalable DNS resolution service within Azure. You no longer need to worry about deploying VMs for DNS, maintaining uptime, or handling patches. Built-in high availability and security features help protect your DNS infrastructure from failures and threats. This integration complements on-premises forwarding by serving as a reliable resolution point close to your Azure resources.

Together, these strategies deliver a robust, low-latency name resolution framework for hybrid networks. They help maintain seamless connectivity between on-premises data centers and Azure, supporting applications that rely on DNS. Implementing both conditional forwarding and Azure DNS Private Resolver ultimately reduces operational overhead and enhances network performance. These solutions are key to a smooth, secure hybrid cloud deployment.