What design approach should Paris use to prevent communication between Human Resources and the research department?

The best design approach for preventing communication between Human Resources and the research department is network segmentation. This method involves dividing a larger network into smaller, isolated segments. Each segment can have its own security policies and access controls, making it easier to restrict communication between groups.

By implementing network segmentation, Paris can effectively separate the Human Resources department's network from the research department’s network. This means that devices and users in Human Resources will not be able to communicate with those in the research department, enhancing security and ensuring that sensitive information is kept confidential. This is particularly important if the two departments handle different types of data that require varying levels of security.

In contrast, firewall rules primarily focus on filtering traffic at the network's boundary, which may not be sufficient to isolate internal departments effectively. Subnetting, while useful for creating smaller networks, does not inherently include access controls that prevent communication. Intrusion Prevention Systems, on the other hand, are designed to detect and block malicious activities rather than control legitimate traffic flow between departments. Hence, network segmentation is the most effective approach to achieving the goal of restricting inter-departmental communication.