2.3.7. 💡 First Principle: Azure VPN Gateway and ExpressRoute

First Principle: Azure's hybrid connectivity services bridge on-premises networks with Azure Virtual Networks. Their core purpose is to extend your corporate network into the cloud securely, supporting diverse requirements for performance, security, and cost.

What It Is: These are two primary services for establishing a secure connection between your on-premises network and your Azure VNet.

• Azure VPN Gateway:
  • Description: Establishes a secure, encrypted connection (a VPN tunnel) over the public internet.
  • Use Case: Ideal for dev/test environments, small to medium-sized businesses, or as a backup for ExpressRoute. It's a cost-effective way to create a hybrid connection.
• Azure ExpressRoute:
  • Description: Creates a private, dedicated, high-bandwidth connection between your on-premises network and Azure through a connectivity provider. This connection does not go over the public internet.
  • Use Case: Best for mission-critical applications, large data transfers, or scenarios requiring predictable performance, low latency, and high security.

Scenario: A company needs to connect its on-premises data center to Azure. They have a critical application that requires a highly reliable, high-speed connection for daily data synchronization. They also have less critical workloads that need a secure connection but can tolerate the variability of the internet.

Reflection Question: Which hybrid connectivity service would you recommend for the critical application, and which for the less critical workloads? What are the key differences in terms of performance and security?

💡 Tip: VPN Gateway = Secure tunnel over the public internet. ExpressRoute = Private, dedicated connection bypassing the internet.