Which port role is primarily responsible for forwarding packets in RSTP?

In Rapid Spanning Tree Protocol (RSTP), the designated port is the port role responsible for forwarding packets on a network segment. It is the port on a network switch that has the lowest path cost to the root bridge, which is the central point in the spanning tree that all switches use to determine the best path for data packets.

When a switch receives a Bridge Protocol Data Unit (BPDU) from another switch, it evaluates the port costs to determine the best path to the root bridge. The designated port is crucial because it is the interface through which all traffic destined for the root bridge is sent, while other port roles may either block traffic or serve as backup paths to prevent loops.

The root port is essential for connecting a switch to the root bridge, but it does not forward packets on the same segment as the designated port. Other roles, such as alternate and backup, exist for redundancy and loop prevention, but they do not actively forward packets.

In summary, the designated port's primary responsibility in RSTP is to forward packets to ensure efficient communication across the network.