200-301 Question 224
Single answerA network engineer is configuring a switch in a small office to ensure that devices such as PCs and printers connected to access ports can immediately start transmitting traffic without waiting for Spanning Tree Protocol (STP) to converge. Which command should the engineer use to achieve this?
- A
spanning-tree portfast enable
- B
spanning-tree portfast
- C
spanning-tree bpduguard enable
- D
spanning-tree vlan 10 priority 4096
Show answer and explanation
Correct answer: B
Explanation
PortFast is a feature that allows an access port to transition directly to the forwarding state, bypassing the STP listening and learning states. This is especially useful for end devices like PCs and printers to start communicating immediately. The correct command to enable PortFast is 'spanning-tree portfast'.
- A. Incorrect.
This is not a valid syntax for enabling PortFast. The correct command is 'spanning-tree portfast'.
- B. Correct.
'spanning-tree portfast' is the correct command to enable PortFast on an interface, allowing it to bypass listening and learning states for faster connectivity.
- C. Incorrect.
BPDU Guard is a separate feature used to disable a port if a BPDU is received. It is not used to enable PortFast.
- D. Incorrect.
This command is used to configure the STP priority for a specific VLAN, which determines root bridge election. It does not enable PortFast.