VirtualBox VM Setup Guide

Add Oracle’s GPG key and repository:

sudo apt update
sudo apt install -y gnupg wget

Downloads Oracle's public key and adds it to your system. This key is a digital signature that lets your system verify that the VirtualBox software is authentic and hasn't been tampered with.`

wget -O- https://www.virtualbox.org/download/oracle_vbox_2016.asc | sudo gpg --yes --output /usr/share/keyrings/oracle-virtualbox-2016.gpg --dearmor

Adding the official VirtualBox repository to your list of software sources, specifying noble for Ubuntu 24.04 version.

echo "deb [arch=amd64 signed-by=/usr/share/keyrings/oracle-virtualbox-2016.gpg] https://download.virtualbox.org/virtualbox/debian noble contrib" | sudo tee /etc/apt/sources.list.d/virtualbox.list

Install VirtualBox:

sudo apt update
sudo apt install virtualbox-7.1

Check installation: virtualbox

Download Lubuntu 16.04 ISO. Official archived ISO :
https://cdimage.ubuntu.com/lubuntu/releases/16.04/release/

IMPORTANT

If VMWare is installed then it has to be turned off from using KVM sudo rmmod kvm_intel or for amd sudo rmmod kvm_amd Then Unload the main KVM Module sudo rmmod kvm

Create a Virtual Machine in VirtualBox

Launch VirtualBox, Click "New" and configure :

Network Settings

Two main options depending on your use case.

a. NAT (Default – For Internet Access)

• Go to Settings > Network

• Adapter 1: Attached to NAT

• This allows the VM to access the internet through your host system

b. Detached Mode (for GNS3 or Host-only networking)

• Go to Settings > Network

• Adapter 1: Attached to Bridged Adapter or Host-only Adapter

• Bridged: VM will get IP from the same network as the host (works for GNS3)

• Host-only: Useful for isolated lab setups without internet

c. Add a second adapter for dual-networking

• Adapter 2: Enable and attach to Host-only Adapter or Internal Network as needed for GNS3 or Program Design

Post-Installation Linux Setup

After first login:

• Install sudo

su

apt-get install sudo

usermod -aG sudo vboxuser

exit
reboot

• Update packages:

sudo apt update && sudo apt upgrade -y

• Install openssh-server (for remote access):

sudo apt install openssh-server

• Check SSH service status:

sudo systemctl status ssh

Should see active (running). If not, start and enable it:

sudo systemctl enable ssh
sudo systemctl start ssh

Check listening port (default is 22):

ss -tlnp | grep ssh

Optional: Adjust firewall to allow SSH (if UFW is enabled):

sudo ufw allow ssh
sudo ufw enable

Test SSH Access from Another PC:

ssh yourusername@<ip-of-vm>

ProFTPD Setup is covered in the next programs.