Azure Virtual Networks

Azure Virtual Network (VNet) is the foundational building block for your private network in Azure. It enables you to create your own private space in the Azure cloud, with IP address spaces, subnets, and route tables. VNets allow Azure resources to communicate with each other, with the internet, and with your on-premises networks.

Key Concepts

What is a Virtual Network?

An Azure Virtual Network is a logical representation of your network in the cloud. When you create a VNet, you define a private IP address space for your resources. This IP address space is a collection of private IP addresses that are not routable on the public internet.

Subnets

You can divide your VNet into smaller segments called subnets. Each subnet can contain Azure resources, and you can associate network security groups (NSGs) and route tables with subnets to control traffic flow and security.

IP Addressing

Azure VNet supports both IPv4 and IPv6 addressing. You can assign public or private IP addresses to your resources. Private IP addresses are used for communication within your VNet and with your on-premises networks. Public IP addresses are used to communicate with the internet.

Routing

Azure automatically routes traffic between subnets within the same VNet. You can also define custom route tables to control how traffic is routed, for example, to force traffic through a network virtual appliance (NVA) or a firewall.

Network Security Groups (NSGs)

NSGs are network security firewalls that you can associate with subnets or network interfaces. They contain rules that allow or deny network traffic to Azure resources. You can use NSGs to implement network segmentation and micro-segmentation.

Benefits of Azure Virtual Networks

Isolation and Segmentation: Create isolated network environments for your applications.
Secure Communication: Enable secure communication between Azure resources and between Azure and your on-premises networks.
Scalability: Easily scale your network resources as your needs grow.
Flexibility: Define custom IP address spaces, subnets, and routing rules.
High Availability: Leverage Azure's robust infrastructure for reliable network connectivity.

Getting Started with Virtual Networks

To get started with Azure Virtual Networks, you can use the Azure portal, Azure CLI, or Azure PowerShell. Here's a basic overview of the steps:

Create a Virtual Network: Define the name, region, and address space for your VNet.
Create Subnets: Divide your VNet into smaller subnets.
Deploy Resources: Deploy virtual machines or other Azure resources into your subnets.
Configure Security: Apply Network Security Groups to control traffic.
Establish Connectivity: Connect your VNet to other VNets, on-premises networks, or the internet as needed.

Example: Creating a VNet with the Azure CLI

Here's a simple example of how to create a VNet and a subnet using the Azure CLI:


az network vnet create \
    --resource-group MyResourceGroup \
    --name MyVNet \
    --address-prefix 10.0.0.0/16

az network vnet subnet create \
    --resource-group MyResourceGroup \
    --vnet-name MyVNet \
    --name MySubnet \
    --address-prefix 10.0.1.0/24

Important Note

Ensure that your IP address spaces do not overlap with your on-premises network or other Azure VNets to avoid routing conflicts.

Azure Networking