Practice Test Geeks(STP) Spanning Tree Protocol Practice Test
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Basics and Concepts Flashcards

7 cards from real STP practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 7 Basics and Concepts flashcards as text

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

    Answer: spanning-tree vlan 1 priority 0

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

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

    Answer: Loop Guard

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

  3. What is the function of Root Guard in STP?

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

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

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

    Answer: When the root port on the same switch fails

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

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

    Answer: The switch is guaranteed to become the root bridge

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

  6. Which type of BPDU does the root bridge send, and which type does a non-root switch send upstream when a topology changes?

    Answer: Configuration BPDUs (root); TCN BPDUs (non-root)

    The root bridge periodically sends Configuration BPDUs, while non-root switches send Topology Change Notification BPDUs upstream when they detect a change.

  7. What is the purpose of the STP BackboneFast feature (proprietary Cisco)?

    Answer: Detects indirect link failures and immediately starts aging out the max age timer

    BackboneFast detects indirect link failures through inferior BPDUs and reduces convergence time by skipping the 20-second max age wait.