AZ-500 Microsoft Azure Security Technologies Exam

Plan and implement network security configurations for an App Service Environment

Private Connectivity and Traffic Control

In an App Service Environment, achieving private connectivity and traffic control is vital for protecting your web apps. By using service endpoints and private endpoints, you can restrict access so that only your chosen virtual networks can reach Azure resources. Service endpoints let Azure services recognize your VNet’s identity and switch outbound traffic from public IPv4 to private IPv4 on the Microsoft backbone. Private endpoints, powered by Azure Private Link, assign a private IP address inside your VNet, eliminating public exposure of your app. This setup ensures that traffic flows securely within Azure’s internal network.

To enable service endpoints, you must turn them on in the App Service subnet. Once active, your resources—even those in different subscriptions or regions—can use the secure link back to your VNet. Keep these key considerations in mind:

• Connections may reset when traffic switches from public to private addresses.
• DNS still resolves to public IP addresses, so external queries behave the same.
• Use service tags in NSG rules to allow only the needed Azure service traffic without managing IP ranges.

For even stronger isolation, implement private endpoints to give your App Service a dedicated network interface with a private IP. This approach:

• Keeps all inbound communication inside the Azure backbone.
• Removes the need for a public IP address.
• Complements App Service outbound calls, which still use VNet integration over the Azure infrastructure.

This dual strategy gives you full private connectivity without losing any platform features.

To control the flow of traffic, apply Network Security Groups (NSGs) and Azure Firewall policies on the App Service subnet. Adopt the deny by default, permit by exception principle by:

• Creating NSG rules based on service tags and application security groups.
• Using a user-defined route that forces outbound traffic through an Azure Firewall virtual appliance.
• Defining application rules in the firewall to allow only approved FQDN destinations.

Finally, validate and monitor your network setup with Azure Network Watcher and Firewall diagnostics logs. Use connection monitors to test end-to-end paths and inspect firewall logs for blocked or allowed traffic. Regular checks help you catch misconfigurations and ensure your network security posture remains strong.

Conclusion

In summary, planning and implementing network security for an App Service Environment means using service endpoints and private endpoints to keep traffic inside your VNet. You then enforce rules with NSGs and route outbound traffic through Azure Firewall for precise control. Continuous monitoring with Azure Network Watcher and firewall diagnostics ensures you spot issues early. Together, these configurations provide a secure, private, and well-monitored environment for your App Service workloads.