What type of firewalls serves as a redundancy strategy in network security?

The correct answer highlights a type of firewall designed specifically for Industrial Control Systems (ICS) that incorporates redundancy to enhance network security. ICS-specific firewalls are tailored to secure critical infrastructure, often used in environments like energy, water, and manufacturing systems where operational continuity is vital. By integrating redundancy strategies, these firewalls can ensure that there is no single point of failure in security.

Redundancy in this context means that if one firewall fails or becomes compromised, another can take over to maintain secure communications and protect against unwanted access or attacks. This is particularly important in industries relying heavily on both operational integrity and cybersecurity, as any downtime or security breach could have significant ramifications.

Other types of firewalls, while important in their own right, might not emphasize redundancy as a primary feature. Proxy firewalls act as intermediaries between clients and servers, providing a degree of anonymity but not necessarily built-in redundancy. Stateful firewalls track the state of active connections and make decisions based on the context of the traffic, while stateless packet filters work at a less sophisticated level by inspecting packets independently without the context of established connections. Although these firewalls provide various layers of security, they may not inherently include redundancy strategies inherent to ICS-specific solutions.