CCNA: Cisco Certified Network Associate — Question 738

What are two reasons to configure PortFast on a switch port attached to an end host? (Choose two.)

Answer options

• A. to block another switch or host from communicating through the port
• B. to enable the port to enter the forwarding state immediately when the host boots up
• C. to prevent the port from participating in Spanning Tree Protocol operations
• D. to protect the operation of the port from topology change processes
• E. to limit the number of MAC addresses learned on the port to 1

Correct answer: B, D

Explanation

The correct answers are B and D because PortFast allows the port to bypass the listening and learning states of Spanning Tree Protocol, enabling immediate forwarding when the connected host powers on. Option A is incorrect as PortFast does not block communication; C is wrong because it doesn't prevent participation in Spanning Tree; and E is irrelevant to PortFast's purpose.