What are the messages sent by STP switches called?

In the context of the Spanning Tree Protocol (STP), the specific messages exchanged between switches are known as Bridge Protocol Data Units, commonly abbreviated as BPDUs. These messages play a crucial role in STP by sharing information about the network topology. BPDUs allow switches to communicate which ports are to be designated for forwarding and which will be put in a blocking state to prevent loops in the network.

Each switch participating in STP periodically sends BPDUs to its neighbors to inform them of its bridge ID, port ID, and path cost values. This allows all switches to maintain a consistent view of the network topology and to determine the best paths for frames. By utilizing BPDUs, STP can effectively manage loop-free topologies in Ethernet networks, which is vital for maintaining network stability.

The other terms, such as STP Messages, Bridge Messages, and Switch Messages, do not accurately reflect the standardized terminology used in networking regarding the messages exchanged in the STP process. Using the correct terminology helps ensure clear communication among networking professionals and enhances understanding of network protocols.