Understanding Azure Service Endpoints and Private Endpoints

Introduction

Azure provides powerful networking features to secure and optimize access to its services. Two key options are Service Endpoints and Private Endpoints. This blog explores both, comparing their features, benefits, and limitations.

What Are Service Endpoints?

Service Endpoints extend the private address space of an Azure Virtual Network (VNet) to Azure services, allowing traffic to travel securely over the Azure backbone network instead of the public internet. This enhances security and can reduce network costs.

How Do They Work?

Imagine a scenario where our application in a VNet needs to access an Azure SQL Database. Normally, the traffic might traverse the public internet, exposing potential security risks. With Service Endpoints:

• Traffic remains on Azure's backbone network.

• You can also configure the Azure service to accept traffic only from specific VNets.

Example: Setting Up a Service Endpoint for Azure Storage

1. Activation: Enable the Service Endpoint for Azure Storage on our VNet, directing traffic destined for Azure Storage to stay on Azure’s backbone network.

2. Security Configuration: Restrict access to our Azure Storage account so that only traffic from your VNet is permitted.

Benefits of Service Endpoints

• Security: Traffic stays off the public internet.

• Performance: Lower latency and potentially reduced costs.

• Control: Specify which networks can access your Azure services.

Limitations

• Public endpoints remain accessible unless further restricted.

• Does not provide private IP integration.

What Are Private Endpoints?

Private Endpoints, a newer service, built on the Azure Private Link framework, offer even greater security by assigning a private IP address from our VNet to the Azure service. This approach fully integrates the service into our private network, ensuring that all traffic stays within the VNet.

Key Features of Private Endpoints

• Assigns a private IP to the Azure resource.

• Bypasses public endpoints entirely.

• Supports Network Security Groups (NSGs) for granular control.

Benefits of Private Endpoints

• Enhanced Security: Traffic remains isolated within our VNet.

• On-Premises Connectivity: Seamless access via VPN or ExpressRoute.

• Cross-Region Support: Secure communication across regions.

Limitations

• Higher complexity and cost.

• Requires DNS configuration changes.

Comparing Service Endpoints and Private Endpoints

Understanding Multi-Tenant and Private Tenant Models

When considering Service Endpoints and Private Endpoints, it’s important to understand Azure’s multi-tenant and private tenant models:

• Multi-Tenant Model: Resources are shared among multiple customers, offering cost efficiency but relying on Azure’s logical isolation for security (e.g., Azure SQL Database).

• Private Tenant Model: Dedicated resources for a single customer, ideal for compliance and isolated workloads (e.g., Azure App Service Environment).

Best Practices

• Plan: Map out our network flow to avoid misconfigurations.

• Secure: Use NSGs and monitoring tools alongside endpoints.

• Monitor: Track network traffic to detect anomalies.

Conclusion

Service Endpoints and Private Endpoints are indispensable tools for securing and optimizing Azure connectivity. While Service Endpoints provide a cost-effective and straightforward solution, Private Endpoints offer advanced security and isolation. Choose the right option based on your use case, security requirements, and budget to maximize the efficiency and safety of your Azure infrastructure.