Port States for Converged RSTP

CD

Rapid Spanning Tree Protocol (RSTP) is an improvement over the original Spanning Tree Protocol (STP) that was designed to provide a faster convergence time for redundant paths in a switched network. RSTP defines four different port states that allow switches to quickly detect changes in the network topology and respond to them accordingly.

The four port states in RSTP are:

1. Discarding (also known as Blocking): This state is entered when a switch port initially starts up or when there is a change in the network topology that requires the switch to re-evaluate the state of its ports. In this state, the switch does not forward any frames and only listens to the network traffic to determine if there are any loops or other issues in the topology.

2. Learning: After the discarding state, the port moves into the learning state. In this state, the switch port listens to the network traffic and learns the source MAC addresses of the frames that it receives. It does not forward any frames yet, but it does update its MAC address table with the new information.

3. Forwarding: After the learning state, the port moves into the forwarding state. In this state, the switch forwards all frames that it receives and updates its MAC address table accordingly.

4. Disabled: This state is entered when a switch port is manually shut down or when there is a hardware failure. The port does not participate in STP and does not forward any frames.

When RSTP has converged, the two port states that are active are:

1. Forwarding: This is the normal state for ports that are actively forwarding frames in the network.

2. Discarding: This state is still active on some ports that are not currently forwarding frames, but are still part of the topology. These ports are in a standby mode and will become active if the current active forwarding ports fail or if a new switch