Network Architecture Design

Network Architecture Design

Effective lab network design balances isolation, realism, and accessibility. Simple flat networks suffice for basic vulnerability exploitation, but more complex architectures teach important concepts about network segmentation, pivoting, and lateral movement. Understanding virtualization networking modes—NAT, host-only, and bridged—enables creation of isolated environments that mirror enterprise architectures.

Creating multiple network segments teaches valuable lessons about real-world penetration testing. A DMZ network containing web servers, an internal network with workstations and domain controllers, and a management network for administrative access mirrors common enterprise designs. Configuring virtual routers between segments enables practicing routing attacks and pivoting techniques. This architecture complexity can be built incrementally as skills develop.

Implementing network security controls within labs provides defensive perspective alongside offensive techniques. Configuring firewalls between network segments forces learning about port restrictions and firewall evasion. Adding IDS/IPS systems like Snort or Suricata teaches detection evasion techniques. Including security information and event management (SIEM) systems helps understand how attacks appear to defenders. This blue team perspective enriches red team skills.

Internet connectivity requires careful consideration in lab environments. While some testing requires internet access, connecting vulnerable systems directly to the internet invites compromise. Network isolation using host-only adapters prevents external access while maintaining inter-VM communication. When internet access is necessary, careful firewall rules and network segmentation limit exposure. Some testers maintain completely air-gapped labs for sensitive testing.