Cisco Certified Network Associate (200-301 CCNA) – Question179

What occurs when PortFast is enabled on an interface that is connected to another switch?

A. Root port choice and spanning-tree recalculation are accelerated when a switch link goes down.
B. After spanning-tree converges, PortFast shuts down any port that receives BPDUs.
C. VTP is allowed to propagate VLAN configuration information from switch to switch automatically.
D. Spanning-tree fails to detect a switching loop increasing the likelihood of broadcast storms.

Correct Answer: D

Explanation:

Explanation:
Enabling the PortFast feature causes a switch or a trunk port to enter the STP forwarding-state immediately or upon a linkup event, thus bypassing the listening and learning states.
Note: To enable portfast on a trunk port you need the trunk keyword “spanning-tree portfast trunk”