Which three functions are performed by the RE?

The Routing Engine (RE) in Juniper devices plays a crucial role in the overall functioning of the device. One of its primary responsibilities is to manage the Packet Forwarding Engine (PFE). The RE handles the control plane processes, allowing for the efficient management of routing information and forwarding decisions. This management includes leveraging the PFE for packet handling, ensuring that data flows smoothly according to the forwarding tables and application of routing protocols.

While the RE does involve itself in the maintenance of the forwarding tables, monitoring the chassis, and applying routing protocols, the most distinctive function among the choices provided is the management of the PFE, which emphasizes the RE's role in directing how packets are processed and forwarded by the hardware.