What is the best approach to securing environmental systems from unauthorized access through a compromised staff WiFi network?

Segmenting the WiFi network from the environmental systems is an effective approach to enhancing security. By creating a separate network for the environmental systems, you minimize the risk of unauthorized access that could occur if the staff WiFi is compromised. This segmentation makes it more difficult for an attacker who has gained access to the staff WiFi to reach the environmental systems, as they would need to bypass additional security controls or network barriers.

Network segmentation involves dividing a computer network into smaller subnetworks, which can isolate sensitive systems and better control traffic between different parts of the organization. It allows for the implementation of stricter security policies on regions of the network that house critical infrastructure, reducing the attack surface and improving overall security posture.

The other choices do not adequately address the security needs as effectively as segmentation. For example, simply implementing Zigbee on WiFi access points may not provide sufficient security, as it does not address the fundamental concern of network access. Installing a smart meter on the staff WiFi does not inherently enhance security and could actually introduce more vulnerabilities. Placing systems in the same DHCP scope can facilitate easier access and management, but it does the opposite of securing the systems, making them more vulnerable to attacks that could exploit a compromised staff WiFi network.