STP Basics and Concepts 5

Question 1

Which command is used on a Cisco switch to manually set a switch as the root bridge using a specific priority?

Accepted Answer

spanning-tree vlan 1 priority 0

Answer

Setting spanning-tree vlan 1 priority 0 gives the switch the lowest possible bridge priority, making it the root bridge.

Question 2

What STP feature prevents a port from transitioning to Forwarding if it stops receiving BPDUs from the designated switch?

Accepted Answer

Loop Guard

Answer

Loop Guard moves a port into a loop-inconsistent state instead of transitioning to Forwarding when BPDUs are no longer received, preventing undetected loops.

Question 3

What is the function of Root Guard in STP?

Accepted Answer

Prevents inferior BPDUs from causing a new root election on designated ports

Answer

Root Guard places a port in root-inconsistent state if a superior BPDU is received, preventing unauthorized switches from becoming the root bridge.

Question 4

In which scenario would an STP alternate port transition to the Forwarding state?

Accepted Answer

When the root port on the same switch fails

Answer

An alternate port takes over as root port and transitions to Forwarding when the current root port fails, providing a fast failover path.

Question 5

What is the significance of a Bridge ID of 0 (priority 0) in STP?

Accepted Answer

The switch is guaranteed to become the root bridge

Answer

A bridge priority of 0 is the lowest possible value, ensuring the switch wins the root bridge election regardless of MAC address.

(STP) Spanning Tree Protocol Practice Test

(STP) Spanning Tree Protocol Practice Test

STP Basics and Concepts 5