What are the four RSTP port roles?

In Rapid Spanning Tree Protocol (RSTP), there are indeed specific port roles that help in optimizing switch port functions to reduce convergence times and prevent loops in the network. The correct identification of the RSTP port roles includes Root, Designated, Alternate, and Backup, with each role serving a unique purpose in the topology management.

The Root port is crucial because it is the port on a switch that has the best path to the Root Bridge—the central point in the spanning tree. All switches in the topology maintain this port to ensure continuity toward the Root Bridge.

The Designated port plays a significant role as well. It is the port on a network segment that has the lowest cost path to the Root Bridge among all switches connected to that particular segment. The Designated port is allowed to forward traffic to and from the segment, making it essential for effective communication within the network.

The Alternate port serves as an immediate backup to the Root port. It provides a redundant path to the Root Bridge and will only take over if the Root port fails. This standby capability aids in maintaining network resilience.

Lastly, the Backup port is another important backup option, but for segments where there are redundant links to the same switch. It allows for a quick failover scenario