What are the primary components of the Four Legged Firewall?

The primary components of the Four Legged Firewall architecture are indeed centered around establishing a secure environment by creating distinct zones to manage and control traffic effectively. The model typically divides the network into four segments: a trusted network, an untrusted network, and two Demilitarized Zones (DMZs) for managing inbound and outbound traffic.

In this framework, the trusted zone generally houses internal resources that are protected and require stringent access controls. The untrusted zone represents the external network, such as the internet, where threats can originate. The inbound DMZ serves as a buffer for incoming traffic to the trusted network, allowing for specific services to be accessed from external sources while still protecting internal resources. The outbound DMZ, on the other hand, is designed for managing outgoing traffic and ensuring that data leaving the trusted environment is screened and controlled.

This structured approach helps mitigate risks by isolating different types of traffic and ensuring that only appropriate communications are allowed to pass between these zones. By having distinct boundaries, security policies can be implemented more effectively, focusing on specific traffic types and their associated risks. Thus, this setup enhances overall network security and compliance with frameworks like NERC's CIP requirements.