What is one method to reconfigure three interfaces to increase spare ports on a Junos switch?

Reconfiguring three interfaces as a single trunk link with multiple logical units is an effective method for increasing spare ports on a Junos switch. This approach leverages link aggregation, allowing multiple physical interfaces to be combined into a single logical interface.

By establishing a trunk link with multiple logical units, the switch can handle traffic for multiple VLANs over a single aggregated link. This consolidation not only conserves ports but also enhances bandwidth and provides redundancy. If one physical link in the trunk fails, the remaining links continue to operate, ensuring high availability.

In contrast, other methods, such as reconfiguring as multiple access links or establishing each interface as a standalone link, would not accomplish the same efficiency and bandwidth optimization. These alternatives could lead to a higher consumption of physical ports without providing the benefits of increased throughput and redundancy like a trunked aggregation would. Therefore, the trunk link with logical units offers a smarter solution for increasing port efficiency on a switch.