azure-networking-basics-cli

Mini Azure Project – Build Virtual Network & Subnets via Azure CLI

This mini-lab demonstrates how to build Azure networking fundamentals purely via Azure CLI, without using the Azure Portal.

It is part of my AZ-104 learning path and serves as the foundation for later projects involving NSGs, Load Balancers, VM Scale Sets and Bastion.

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Goals

• Create a Resource Group
• Create an Azure Virtual Network (/16)
• Create multiple Subnets (/24)
• Deploy Virtual Machines into specific subnets
• Understand Azure IP planning and network segmentation
• Work CLI-only (no Portal)

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Prerequisites

• Azure Subscription
• Azure CLI or Azure Cloud Shell
• Basic understanding of IP addressing & CIDR

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Section 1 - Section 1 – Build Virtual Network, Subnets and deploy VMs into specific subnets

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Step 1 - Create Resource Group

az group create \
  --name rg-networking \
  --location westeurope \
  --output table

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Step 2 - Create Virtual Network

az network vnet create \
  --resource-group rg-networking \
  --name vnet-main \
  --address-prefix 10.0.0.0/16 \
  --location westeurope \
  --output table

Why /16?

• Large address space for future growth (subnets, scaling, services).
• Best practice in Azure to avoid early re-addressing.

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Step 3 Create Subnets

Subnet 1 - Frontend

az network vnet subnet create \
  --resource-group rg-networking \
  --vnet-name vnet-main \
  --name subnet-frontend \
  --address-prefix 10.0.1.0/24

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Subnet 2 - Backend

az network vnet subnet create \
  --resource-group rg-networking \
  --vnet-name vnet-main \
  --name subnet-backend \
  --address-prefix 10.0.2.0/24

Why /24?

• 256 IPs per Subnet
• Azure reserves 5 -> 251 usable IPs
• Clean separation & easy scaling

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Step 4 - Deploy VM into Frontend Subnet

az vm create \
  --resource-group rg-networking \
  --name vm-frontend01 \
  --image Ubuntu2204 \
  --size Standard_B2s \
  --admin-username azureuser \
  --generate-ssh-keys \
  --vnet-name vnet-main \
  --subnet subnet-frontend \
  --public-ip-sku Standard \
  --output table

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Step 5 Deploy VM into Backend Subnet

az vm create \
  --resource-group rg-networking \
  --name vm-backend01 \
  --image Ubuntu2204 \
  --size Standard_B2s \
  --admin-username azureuser \
  --generate-ssh-keys \
  --vnet-name vnet-main \
  --subnet subnet-backend \
  --public-ip-sku Standard \
  --output table

Note: In a real-world setup, backend VMs would not have a public IP and would only be reachable via Bastion, Load Balancer or private access. This is intentionally simplified for learning purposes.

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Step 6 - Verify Network Placement

az vm list-ip-addresses \
  --resource-group rg-networking \
  --output table

Proof - Verify Placement

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Cleanup (optional)

az group delete \
  --name rg-networking \
  --yes \
  --no-wait

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Learnings

• Azure IP planning (/16 VNet + /24 subnets)

• CLI-based network creation

• Subnet isolation & design

• Deploying VMs into specific subnets

• Foundation for:

• NSGs

• Bastion

• Load Balancers

• VM Scale Sets

Next Steps

• Add Network Security Groups (NSG)
• Restrict traffic between subnets
• Remove public IP from backend VM
• Introduce Azure Bastion
• Combine with VMSS & Load Balancer