To provide employees with computers that do not have access to the internet and prevent information leaks to an online forum, implementing an air gap would be the best solution. An air gap physically isolates the computer or network from any outside connections, including the internet, ensuring that data cannot be transferred to or from the system.
Air gap: A security measure that isolates a computer or network from the internet or other networks, preventing any form of electronic communication with external systems.
Jump server: A secure server used to access and manage devices in a different security zone, but it does not provide isolation from the internet.
Logical segmentation: Segregates networks using software or network configurations, but it does not guarantee complete isolation from the internet.
Virtualization: Creates virtual instances of systems, which can be isolated, but does not inherently prevent internet access without additional configurations.