Which option describes how a switch in rapid PVST+ mode responds to a topology change?

Which option describes how a switch in rapid PVST+ mode responds to a topology change?
A . It immediately deletes dynamic MAC addresses that were learned by all ports on the switch.
B . It sets a timer to delete all MAC addresses that were learned dynamically by ports in the same STP instance.
C . It sets a timer to delete dynamic MAC addresses that were learned by all ports on the switch.
D . It immediately deletes all MAC addresses that were learned dynamically by ports in the same STP instance.

View Answer

Answer: D

Explanation:

Rapid PVST+

This spanning-tree mode is the same as PVST+ except that is uses a rapid convergence based on the IEEE 802.1w standard. To provide rapid convergence, the rapid PVST+ immediately deletes dynamically learned MAC address entries on a per-port basis upon receiving a topology change. By contrast, PVST+ uses a short aging time for dynamically learned MAC address entries.

The rapid PVST+ uses the same configuration as PVST+ (except where noted), and the switch needs only minimal extra configuration. The benefit of rapid PVST+ is that you can migrate a large PVST+ install base to rapid PVST+ without having to learn the complexities of the MSTP configuration and without having to reprovision your network. In rapid-PVST+ mode, each VLAN runs its own spanning-tree instance up to the maximum supported.