Plan private endpoints

4.1 Azure Private Link and Private Endpoints

📘Microsoft Azure Networking Solutions (AZ-700)

---

What is a Private Endpoint?

A Private Endpoint in Azure is a network interface that connects you privately and securely to an Azure service over a private IP address from your virtual network (VNet).

• Instead of using a public endpoint (public IP and internet), you access Azure services like Azure Storage, Azure SQL, or Azure Key Vault directly over your private network.
• This ensures no traffic goes over the internet, which improves security and compliance.

Think of it as a “private door” to Azure services that only your network can use.

---

Key Concepts

1. Private Link
   • This is the underlying technology that enables Private Endpoints.
   • Private Link allows Azure services and your resources to communicate privately.
   • Example services that support Private Link:
     • Azure Storage (Blobs, Files)
     • Azure SQL Database
     • Azure Key Vault
     • Azure App Configuration
2. Private Endpoint vs Service Endpoint
   • Service Endpoint: Extends your VNet to Azure service but uses public IP; firewall rules may still allow internet access.
   • Private Endpoint: Assigns a private IP to the Azure service inside your VNet; fully private and secure.

---

When to Plan for a Private Endpoint

You need a Private Endpoint in scenarios such as:

1. Security Requirements:
   • When your company policy or regulatory requirements do not allow traffic over the internet.
   • Example: HIPAA or PCI compliance.
2. Access from On-Premises:
   • You have a VNet connected to on-premises via VPN or ExpressRoute and want your on-premises apps to access Azure services privately.
3. Multi-tenant Service Access:
   • If you want to securely connect to a service hosted by another organization (like SaaS) without exposing it publicly.

---

Planning Steps for Private Endpoints

1. Identify the Azure Service

• Determine which service you need to connect to privately (SQL, Storage, Key Vault, etc.).
• Ensure the service supports Private Link.

2. Choose the VNet and Subnet

• Private Endpoints require a subnet in your VNet.
• Best practice:
  • Use a dedicated subnet for Private Endpoints.
  • Avoid putting regular VMs in the same subnet to reduce conflicts.

3. DNS Planning

• Private Endpoints use private DNS zones to resolve the service name to the private IP.
• Azure can automatically create a private DNS zone for you, or you can link an existing DNS solution.
• Important DNS records:
  • Example: myaccount.blob.core.windows.net → Private IP in your VNet.

4. Network Security

• Ensure NSGs (Network Security Groups) allow traffic to the Private Endpoint.
• Only required ports should be open (e.g., 443 for HTTPS).

5. Access Control

• Private Endpoints inherit role-based access control (RBAC) from the Azure service.
• Users and apps must have proper permissions to access the service.

6. Integration with On-Premises

• If you have VPN or ExpressRoute, make sure private DNS resolution works for on-premises clients.
• This ensures services accessed over Private Endpoint appear as internal addresses.

7. Audit and Monitoring

• Use Azure Monitor and Network Watcher to track:
  • Connection health
  • Traffic flow
  • Unauthorized access attempts

---

Key Exam Points

• Definition: Private Endpoint = Private IP inside your VNet to access Azure service securely.
• Difference: Private Endpoint ≠ Service Endpoint (Private Endpoint is fully private).
• Use Cases: Security, compliance, on-premises access, multi-tenant services.
• DNS: Must plan private DNS resolution for services.
• Subnet: Recommended to use dedicated subnet.
• RBAC & NSG: Permissions and network security still apply.

---

Example in IT Environment

• Your company has an Azure SQL Database.
• You don’t want it accessible over the internet.
• You create a Private Endpoint in your VNet subnet.
• The SQL database now has a private IP inside your VNet.
• Applications in your VNet (or connected on-premises network) can access SQL database securely, without ever using the public internet.

---

✅ Summary for the Exam

• Know what Private Endpoints are and why they’re used.
• Know how to plan: service, subnet, DNS, NSG, RBAC.
• Understand use cases: secure access, compliance, on-premises integration.
• Be ready to choose Private Endpoint vs Service Endpoint depending on the scenario.