Overview
In this project, I designed and implemented a virtual network lab using Linux systems to simulate real-world networking environments and troubleshooting scenarios.
The lab was built using Oracle VM VirtualBox, with two virtual machines (Ubuntu and Kali Linux) configured to communicate across isolated and internet-connected networks.
This project focused on network configuration, troubleshooting, and packet-level analysis.
Environment Setup
- Virtualization platform: VirtualBox
- Operating Systems:
- Ubuntu Linux (client system)
- Kali Linux (security/testing system)
Network Architecture
The environment was configured with a dual-network design:
- NAT Network:
- Provides internet access
- Uses DHCP (10.0.2.x range)
- Internal Network (lab-network):
- Enables communication between virtual machines
- Uses manually assigned IP addresses (192.168.100.x)
Technical Challenges & Troubleshooting
During the implementation, several real-world networking issues were identified and resolved:
- Duplicate IP addresses due to NAT configuration
- No DHCP available in the internal network
- “Network unreachable” errors
- DNS resolution failure (“temporary failure in name resolution”)
- Incorrect routing and interface selection
- Loss of internet connectivity due to missing IP on network interface
Solutions Implemented
To resolve these issues, I:
- Configured an internal network in VirtualBox for isolated communication
- Manually assigned static IP addresses to both systems
- Verified and corrected routing tables
- Configured DNS manually using a public DNS server (8.8.8.8)
- Diagnosed interface issues and restored connectivity
- Rebuilt network configuration manually when DHCP was unavailable
Network Analysis (Wireshark)
Using Wireshark, I captured and analyzed network traffic to validate connectivity and understand protocol behavior.
ICMP Analysis
- Captured ping (ICMP) traffic between Ubuntu and Kali
- Verified bidirectional communication
- Analyzed packet details including:
- Source and destination IP
- ICMP request and reply types
DNS Analysis
- Captured DNS queries during external communication
- Observed domain resolution process (google.com → IP)
- Verified proper DNS functionality
Commands Used
bash
ip a
ip route
ping
ping google.com
ping 8.8.8.8
sudo ip addr add …
sudo ip link set …
sudo ip route add …
sudo nano /etc/resolv.conf
Skills Demonstrated
- Linux System Administration
- Network Configuration (IP, DNS, Routing)
- Troubleshooting Methodology
- Virtualization (VirtualBox)
- Packet Analysis (Wireshark)
- Problem Diagnosis and Resolution
Outcome
This project demonstrates hands-on experience in building and troubleshooting a virtual network environment, as well as analyzing network traffic at the packet level.
It reflects real-world IT support and networking tasks, including diagnosing connectivity issues and implementing solutions.