2.3.6. 💡 First Principle: Azure Virtual Network (VNet)

First Principle: Azure Virtual Network (VNet) is the fundamental building block for your private network in Azure. Its core purpose is to provide an isolated, secure, and customizable network environment for your cloud resources to communicate with each other, the internet, and on-premises networks.

What It Is: A VNet is a logical representation of your own network in the cloud. It allows you to create a private, isolated section of the Azure cloud.

Key Concepts:

• Isolation: VNets provide network-level isolation, ensuring resources in one VNet cannot communicate with resources in another unless explicitly configured.
• Subnets: You can segment a VNet into one or more subnets, which are smaller IP address ranges. This allows for better organization and the application of specific security rules to groups of resources.
• VNet Peering: Connects two Azure VNets, allowing them to communicate as if they were on the same network.

Scenario: You are deploying a three-tier application with a web front-end, an application middle-tier, and a database back-end. You need to ensure that the database is isolated and can only be accessed by the application tier, not directly from the web tier or the internet.

Reflection Question: How would you use subnets within a VNet to achieve the required network isolation for this three-tier application?

💡 Tip: Think of a VNet as your private network in the cloud. Subnets are like different rooms within that network, and you can control who can go from one room to another.