This project demonstrates a segmented cybersecurity lab built using Oracle VirtualBox. Three Linux virtual machines are separated across two isolated LANs, with a dual-homed Linux Mint system providing the only connection between the external and internal network segments.
The lab demonstrates network segmentation, multi-NIC configuration, routing verification, SSH access, connectivity testing, and controlled pivoting between isolated networks.
LAN 1: 192.168.10.0/24
Kali ↔ Linux Mint
LAN 2: 192.168.20.0/24
Linux Mint ↔ Ubuntu
Linux Mint is dual-homed, with one network interface connected to each LAN.
The environment consists of three Linux virtual machines running simultaneously in VirtualBox.
Screenshot: VirtualBox environment showing Kali Linux, Linux Mint and Ubuntu.
Linux Mint provides the connection point between the two isolated networks.
The Mint routing table confirms two active network connections:
192.168.10.0/24 → 192.168.10.3
192.168.20.0/24 → 192.168.20.3
This allows Mint to communicate directly with systems on both LANs.
Connectivity testing was performed to verify the segmentation design.
| Test | Result |
|---|---|
| Kali → Mint | ✅ Reachable |
| Mint → Ubuntu | ✅ Reachable |
| Kali → Ubuntu | ❌ No Direct Access |
ping 192.168.10.3
ping 192.168.20.2
ping 192.168.20.2
The failed direct connection demonstrates that Kali and Ubuntu remain isolated on separate network segments.
SSH is used to establish access from Kali to the dual-homed Mint system.
ssh <username>@192.168.10.3
From the Mint system, the internal Ubuntu host on 192.168.20.2 becomes reachable through LAN 2.
Kali Linux
192.168.10.2
│
│ SSH
▼
Linux Mint
192.168.10.3
192.168.20.3
│
│ Internal LAN
▼
Ubuntu
192.168.20.2
Final path: Kali → Linux Mint → Ubuntu
- VirtualBox network configuration
- Network segmentation and subnetting
- Linux TCP/IP configuration
- Dual-NIC / multi-homed host configuration
- Linux routing analysis
- ICMP connectivity testing
- SSH remote access
- Network isolation verification
- Pivoting between segmented networks
VirtualBox Kali Linux Linux Mint Ubuntu SSH TCP/IP IPv4
This project was performed entirely within an isolated, locally controlled virtual lab for cybersecurity education and network administration practice.