Attaching A Network Interface (NIC) to VM

🎯 Objective

Attach an additional Network Interface Card (NIC) to an Azure Virtual Machine to enable advanced networking and traffic separation.

🧠 What is a NIC in Azure?

In Microsoft Azure, a Network Interface (NIC) is a virtual network adapter that connects a VM to a Virtual Network (VNet).

Each NIC can have:

⚙️ Why Attach Multiple NICs?

⚠️ Requirements

Before attaching a NIC:

🖥️ Method 1: Attach NIC via Azure Portal

Steps:

1. Go to Microsoft Azure Portal

1. Navigate to Virtual Machines

1. Select your VM

1. Click Stop (Deallocate)

1. Go to Networking

1. Click Attach network interface

1. Select an existing NIC or create a new one

1. Click Attach

1. Start the VM again

💻 Method 2: Attach NIC using Azure CLI

Step 1: Create NIC (if not created)

az network nic create \
--resource-group myResourceGroup \
--name myNIC \
--vnet-name myVNet \
--subnet mySubnet

Step 2: Stop the VM

az vm deallocate \
--resource-group myResourceGroup \
--name myVM

Step 3: Attach NIC

az vm nic add \
--resource-group myResourceGroup \
--vm-name myVM \
--nics myNIC

Step 4: Start VM

az vmstart \
--resource-group myResourceGroup \
--name myVM

🔍 Verify NIC Attachment

az vm show \
--name myVM \
--resource-group myResourceGroup \
--query"networkProfile.networkInterfaces"

🧠 Inside the VM (Linux)

After attaching NIC, check interfaces:

ip a

You may see:

👉 You might need to:

🧠 Real DevOps Use Cases

🌐 Multi-tier architecture

🔐 Security isolation

🔀 Load balancing / routing setups

⚠️ Important Notes

🔥 Pro Tips