Quick Answer

The correct order begins with the switch detecting a topology change and sending a proposal message, followed by the neighbor receiving it, synchronizing, and sending an agreement, after which the switch sets the port to forwarding and propagates the topology change via TC messages using the TC-while timer. This sequence is fundamental to Rapid PVST+ because it replaces the slower 802.1D convergence with a synchronized handshake that immediately notifies all switches in the VLAN of the change, preventing temporary loops and reducing convergence time to seconds. On the ENCOR 350-401 exam, this topic tests your understanding of the Rapid PVST+ topology change notification steps as a distinct process from classic STP, often appearing in drag-and-drop or scenario-based questions where a common trap is confusing the proposal-agreement handshake with the later TC propagation phase. Remember that the proposal and agreement happen first on the local link, while the TC-while timer is the final step that floods the change to the rest of the network. A helpful mnemonic is “Propose, Agree, Forward, then TC-while,” keeping the local synchronization before the global notification.