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Firewalls are essential for ensuring the secure flow of necessary traffic between IT (Information Technology) and OT (Operational Technology) networks. They help keep bad actors from compromising OT systems when configured correctly. Many environments already have a firewall between IT and OT, limiting traffic movement from Point A to Point B. This is a great start, but having only one firewall can be risky. If it fails, attackers could bypass it, leading to potential breaches.
Why Two Firewalls?
- Resilience: A second firewall adds an extra layer of security.
2. Safety: Keeps people and systems safe.
- Attack Prevention: Slows down attackers and stops malware from spreading.
- Disaster Prevention: Prevents environmental disasters by securing critical infrastructure.
5. Operational Continuity: Ensures the plant remains operational.
For more mature security programs, consider using firewalls from different vendors. If an attacker bypasses one brand, they are unlikely to bypass the second. Additionally, multiple firewalls allow for the implementation of an IT/OT DMZ (Demilitarized Zone), enabling secure data transfer between networks.
Practical Commands and Configurations
Here are some practical commands and configurations to enhance your firewall setup:
1. iptables (Linux):
<h1>Allow traffic from IT to OT on specific ports</h1> iptables -A FORWARD -i eth0 -o eth1 -p tcp --dport 80 -j ACCEPT iptables -A FORWARD -i eth0 -o eth1 -p tcp --dport 443 -j ACCEPT <h1>Block all other traffic between IT and OT</h1> iptables -A FORWARD -i eth0 -o eth1 -j DROP
2. Windows Firewall:
<h1>Allow specific traffic between IT and OT</h1> New-NetFirewallRule -DisplayName "Allow IT-OT Traffic" -Direction Inbound -LocalPort 80,443 -Protocol TCP -Action Allow <h1>Block all other traffic</h1> New-NetFirewallRule -DisplayName "Block IT-OT Traffic" -Direction Inbound -Action Block
3. Cisco ASA Firewall:
access-list IT-OT-TRAFFIC extended permit tcp any any eq 80 access-list IT-OT-TRAFFIC extended permit tcp any any eq 443 access-list IT-OT-TRAFFIC extended deny ip any any
What Undercode Say
Firewalls are a critical component of any cybersecurity strategy, especially when securing the boundary between IT and OT networks. While a single firewall provides a basic level of protection, adding a second firewall significantly enhances security by introducing redundancy and diversity in defense mechanisms. Using firewalls from different vendors further complicates an attacker’s ability to bypass security measures. Implementing an IT/OT DMZ can also facilitate secure data transfer between networks, ensuring operational continuity and safety.
In addition to firewalls, consider using intrusion detection systems (IDS) and intrusion prevention systems (IPS) to monitor and block malicious activities. Regularly update firewall rules and configurations to adapt to evolving threats. Employing network segmentation and zero-trust principles can further strengthen your security posture.
For more advanced configurations, explore tools like pfSense, Fortinet, and Palo Alto Networks. These platforms offer robust features for managing complex network environments. Additionally, leverage logging and monitoring tools such as Splunk or ELK Stack to analyze traffic and detect anomalies.
Remember, cybersecurity is an ongoing process. Regularly review and update your security policies, conduct penetration testing, and stay informed about the latest threats and vulnerabilities. By adopting a multi-layered defense strategy, you can significantly reduce the risk of cyberattacks and ensure the resilience of your IT and OT networks.
For further reading, check out these resources:
References:
Hackers Feeds, Undercode AI
