Breaking a lab network on purpose
A controlled Kali-and-Metasploitable lab: ARP spoofing, sniffing, SYN flooding, Smurf attacks, and the human side of social engineering.
The setup
The lab ran on VMware Workstation/Fusion with two virtual machines: Kali Linux as the attacker and Metasploitable2 as the target, alongside a physical host. Before any attack, I mapped the network — interfaces, addresses, gateway, DNS and connectivity — so I could tell the difference between "the attack failed" and "the machines were never talking".
The attacks
- ARP spoofing — poisoning the association between an IP address and a MAC address to place the attacker between two hosts.
- Sniffing / man-in-the-middle — capturing traffic that was never meant to be visible, and seeing how much of a local network trusts its neighbours.
- TCP SYN flooding — exhausting connection state with half-open handshakes.
- Smurf attack — using broadcast traffic and spoofed source addresses to amplify a denial-of-service.
- Social engineering — a credential-harvesting page and a trapped link, because the easiest way into a system is often a person.
What I learned
Each attack exploits a different kind of trust. ARP trusts the local network, TCP trusts the handshake, and people trust a familiar-looking link. The defensive lessons are just as layered: dynamic ARP inspection and segmentation, rate limiting and SYN cookies, egress filtering, and user awareness that does not rely on blaming the user.
Everything stayed inside an isolated lab environment.
Tools
Kali Linux · Metasploitable2 · VMware · ARP spoofing · TCP SYN flood · Social engineering