CCNA: Cisco Certified Network Associate — Question 241

Which spanning-tree enhancement avoids the learning and listening states and immediately places ports in the forwarding state?

Answer options

• A. BPDUfilter
• B. PortFast
• C. Backbonefast
• D. BPDUguard

Correct answer: B

Explanation

PortFast is the correct answer because it allows ports to enter the forwarding state immediately without undergoing the learning and listening states, which is useful for devices like servers and workstations that do not create network loops. The other options, such as BPDUfilter and BPDUguard, serve different purposes related to BPDU handling and loop prevention, while Backbonefast is used to speed up the convergence process after a topology change.