Setting up an ICS Network Following the Purdue Model - Paiet/Capstone GitHub Wiki

Introduction: The Purdue Model, also known as the Purdue Enterprise Reference Architecture, is a framework for designing and securing Industrial Control System (ICS) networks. This document provides step-by-step instructions for setting up and securing an ICS network using the Purdue Model.

Step 1: Define the Network Zones The Purdue Model divides an ICS network into hierarchical zones based on their functionality and security requirements. The zones are:

  1. Enterprise Zone: This zone includes the corporate IT network, which is typically isolated from the ICS network.
  2. DMZ Zone: This zone provides a secure area for external communication, such as remote access or third-party connections.
  3. Perimeter Zone: This zone includes the ICS network boundary and provides security mechanisms, such as firewalls and intrusion detection systems (IDS).
  4. Control Network Zone: This zone includes the ICS components, such as PLCs, RTUs, and HMIs.
  5. Cell/Area Zone: This zone includes the field devices and sensors that are connected to the ICS components.

Step 2: Design the Network Topology Once the network zones have been defined, the next step is to design the network topology. The topology should ensure that each zone is isolated from the others and that traffic flow is controlled using security mechanisms, such as firewalls and VPNs.

Step 3: Implement Network Security Mechanisms For the implementation of network security mechanisms in our Capstone project, we have chosen to use various devices from Automation Direct, Cisco, and Palo Alto Networks. These devices are designed to provide different levels of security and can be integrated to form a comprehensive security system.

To begin with, we have used Automation Direct's industrial Ethernet switches to segment our ICS network into different zones. These switches are designed to operate in harsh environments and provide features such as VLAN support and port mirroring.

We have also deployed a Cisco ASA firewall to provide perimeter security and control traffic flow between the network zones. Cisco's industrial Ethernet switches have been used to segment our ICS network further. Additionally, we have implemented IDS/IPS, and VPNs to detect and prevent attacks and provide secure remote access to our network.

Furthermore, we have employed Palo Alto Networks' next-generation firewalls that provide advanced security features like threat prevention and application visibility and control. We have used these firewalls to provide perimeter security and control traffic flow between the network zones. We have also utilized Palo Alto Networks' network security appliances to secure our ICS components and field devices.

The combination of devices from Automation Direct, Cisco, and Palo Alto Networks has allowed us to create a comprehensive security system that provides multiple layers of security to protect our ICS network. We have configured firewall rules to restrict traffic between the zones, IDS/IPS to detect and prevent attacks, and network segmentation to isolate critical components.

We have also implemented automation and centralized management tools to simplify the management of the security system and ensure that it remains up-to-date with the latest security policies and procedures.

Overall, our Capstone project has successfully implemented a comprehensive security system using devices from Automation Direct, Cisco, and Palo Alto Networks.