|Exam 200-120||Question id=92||LAN Switching Technologies|
Which statements about RSTP are true?
RSTP significantly reduces topology reconverging time after a link failure.|
RSTP expands the STP port roles by adding the alternate and backup roles.|
RSTP port states are blocking, discarding, learning, or forwarding.|
RSTP provides a faster transition to the forwarding state on point-to-point links than STP does.|
RSTP also uses the STP proposal-agreement sequence.|
RSTP uses the same timer-based process as STP on non-broadcast links.|
Rapid transition is the most important feature introduced by 802.1w. The legacy STA passively waited for the network to converge before it turned a port into the forwarding state. The achievement of faster convergence was a matter of tuning the conservative default parameters (forward delay and max_age timers) and often put the stability of the network at stake. The new rapid STP is able to actively confirm that a port can safely transition to the forwarding state without having to rely on any timer configuration. There is now a real feedback mechanism that takes place between RSTP-compliant bridges. In order to achieve fast convergence on a port, the protocol relies upon two new variables: edge ports and link type.