nerdexam
Cisco

200-301 · Question #25

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

The correct answer is A. Spanning tree may fail to detect a switching loop in the network that causes broadcast storms. 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

Submitted by olafpl· Mar 5, 2026

Question

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

Options

  • ASpanning tree may fail to detect a switching loop in the network that causes broadcast storms
  • BVTP is allowed to propagate VLAN configuration information from switch to switch automatically.
  • CRoot port choice and spanning tree recalculation are accelerated when a switch link goes down
  • DAfter spanning tree converges PortFast shuts down any port that receives BPDUs.

How the community answered

(31 responses)
  • A
    90% (28)
  • B
    6% (2)
  • C
    3% (1)

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

Topics

#PortFast#STP#switching loops#broadcast storms

Community Discussion

No community discussion yet for this question.

Full 200-301 Practice