Exploring VirtualBox Networking and Understanding Cloud Networking

Introduction

Before learning cloud networking technologies such as AWS VPC, Azure Virtual Network, and Google Cloud VPC, it is useful to understand how virtual machines communicate with each other and with external networks.

VirtualBox provides several networking modes that simulate real-world networking scenarios. By experimenting with these modes, students can visualize concepts that later appear in cloud networking architectures.

In this tutorial, you will create two virtual machines and observe how different VirtualBox networking modes affect connectivity.

Lab Environment

Host Computer:

• Windows 11

Virtual Machines:

• Xubuntu VM 1

• Xubuntu VM 2

Tools:

• VirtualBox

• Terminal

• ping command

• ip addr command

---

Part 1: NAT Mode

Configure NAT

1. Shutdown the VM.

2. Open VirtualBox.

3. Select VM.

4. Settings → Network.

5. Adapter 1:

   • Enable Network Adapter

   • Attached To: NAT

6. Start the VM.

Check IP address:

ip addr

Expected:

10.0.2.x

Test Internet access:

ping google.com

Observation

The VM can:

• Access the Internet

• Download software

• Browse websites

The VM cannot:

• Receive inbound connections from other devices

Cloud Networking Analogy

NAT Mode is similar to:

• Private EC2 instance accessing Internet through NAT Gateway

• Private Azure VM using NAT Gateway

• Private subnet with outbound-only access

Concept learned:

Private Network
     |
 NAT Gateway
     |
 Internet

---

Part 2: Bridged Adapter

Configure Bridged Mode

Shutdown VM.

Change Adapter 1:

Attached To:
Bridged Adapter

Start VM.

Check IP:

ip addr

Expected:

192.168.x.x

same network as your home router.

Test from Windows:

ping <vm-ip>

Observation

The VM appears as a real device on the LAN.

Cloud Networking Analogy

Equivalent to:

• VM with Public IP

• EC2 Instance with Elastic IP

• Azure VM with Public IP

Concept:

Internet
    |
 Public IP
    |
 Virtual Machine

---

Part 3: Host-Only Adapter

Configure:

Attached To:
Host-Only Adapter

Start VM.

Expected IP:

192.168.56.x

Test:

Windows Host → VM

Works.

VM → Internet

Fails.

Cloud Networking Analogy

Equivalent to:

• Private Subnet

• Backend Network

• Internal Management Network

Concept:

Administrator
      |
 Private Network
      |
 Backend Servers

---

Part 4: Internal Network

Create two VMs.

Configure both:

Attached To:
Internal Network

Use network name:

lab-net

Assign IPs:

VM1:

sudo ip addr add 10.10.10.1/24 dev enp0s3

VM2:

sudo ip addr add 10.10.10.2/24 dev enp0s3

Test:

ping 10.10.10.2

Observation

VMs communicate with each other.

No Internet.

Host cannot access them.

Cloud Networking Analogy

Equivalent to:

• Isolated subnet

• Database subnet

• Backend application tier

Concept:

Web Server
     |
 Application Server
     |
 Database Server

without Internet exposure.

---

Part 5: Network Architecture Comparison

VirtualBox	Cloud Equivalent
NAT	NAT Gateway
Bridged	Public IP Instance
Host Only	Private Subnet
Internal Network	Isolated Subnet
Multiple Adapters	Multi-Homed Cloud VM

---

What Students Learned

After this tutorial students understand:

• Public vs Private networking

• Network isolation

• NAT concepts

• Multi-tier architecture

• Cloud subnet design

These concepts directly prepare students for AWS VPC, Azure VNet, and GCP VPC networking.