Building a Fortress: A Dive into Secure Enterprise Network Design
Introduction
The importance of robust network design cannot be overstated. As part of a graduate-level network security course, I undertook the challenge of crafting a secure, small enterprise network. In this blog post, I'll walk you through the intricacies of my design, featuring multiple pfSense firewalls, VyOS routers, a DMZ, servers for web, email, and file storage, as well as honeypots and workstations.
The Blueprint
1. The Core Infrastructure
At the heart of my design lies a meticulously crafted core infrastructure. To ensure a resilient and scalable foundation, I opted for pfSense firewalls as my primary defense mechanism. Their feature-rich capabilities, including stateful packet inspection, VPN support, and intuitive management interfaces, made them an ideal choice.
2. pfSense Firewalls and Defense-in-Depth
I employed multiple pfSense firewalls to implement a defense-in-depth strategy. The outermost firewall serves as the perimeter guardian, scrutinizing incoming and outgoing traffic. The second firewall, positioned between the internal network and the DMZ, adds an extra layer of protection. This dual-layered approach minimizes the risk of unauthorized access and enhances the overall security posture.
3. VyOS Routers for Segmentation
VyOS routers played a pivotal role in segmenting the network. By strategically placing routers between different zones, I created isolated segments for enhanced control and security. This segmentation not only aids in containing potential threats but also facilitates efficient traffic management.
4. The DMZ: A Secure Buffer Zone
A demilitarized zone (DMZ) acts as a buffer between the internal network and external entities like the internet. Here, I deployed web servers, email servers, and other services that need to be accessible from both sides. Strict firewall rules and intrusion detection systems (IDS) fortify this area, ensuring that even if a breach occurs, it doesn't immediately compromise the internal network.
5. Servers: Web, Email, and File Storage
The server infrastructure comprises dedicated machines for web hosting, email services, and file storage. Each server is carefully configured with security best practices in mind, including regular updates, strong authentication, and access controls. The separation of these services into distinct servers enhances both performance and security.
6. Honeypots: Deceptive Defense
Incorporating honeypots into the network adds an intriguing layer of deception. These decoy systems are designed to lure potential attackers, allowing us to study their tactics and gather valuable threat intelligence. The honeypots are strategically placed within the DMZ and other critical points, creating an early warning system for potential threats.
7. Workstations: User-Centric Security
Last but not least, the network includes user workstations fortified with endpoint protection solutions. Regular security awareness training for users ensures that the human element is also a part of the defense strategy.
Implementation in a Virtual Environment
To bring this network to life, I utilized virtualization technologies, specifically Cypherpath. This allowed for the creation of virtual instances of pfSense firewalls, VyOS routers, servers, and workstations. The virtual environment provided a safe and controlled space for testing and refining the network architecture before deployment.
Design Rationale
The design choices made throughout this project were driven by a holistic approach to security. By adopting a defense-in-depth strategy, segmenting the network, and incorporating honeypots, the goal was to create a resilient system that could withstand a variety of cyber threats.
In conclusion, designing a secure enterprise network involves more than just connecting devices. It requires careful consideration of potential threats, a strategic approach to segmentation, and the implementation of advanced security features. The virtual environment served as an invaluable testing ground, allowing for the refinement of the network architecture before real-world deployment. As we navigate an increasingly digital landscape, the importance of such secure networks cannot be overstated—they are the fortresses that safeguard our digital assets from the ever-present challenges of the cyber realm.