Practice Test Geeks(ACSP) Aruba Certified Switching Professional Practice Test
← All ACSP Flashcard Decks

Spanning Tree Protocol (STP) Flashcards

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

Read the first 7 Spanning Tree Protocol (STP) flashcards as text

  1. Which RSTP proposal-agreement mechanism element must be true for a port to rapidly transition to Forwarding without going through full STP timers?

    Answer: The link must be point-to-point full-duplex

    RSTP rapid transition via proposal-agreement requires a point-to-point link, which is automatically detected on full-duplex connections.

  2. In MSTP, what is the maximum number of MST instances that can be configured (excluding MSTI 0/CIST)?

    Answer: 15

    IEEE 802.1Q allows up to 64 MST instances total (0-63), with MSTI 0 reserved as the CIST, leaving 63 configurable instances, but most vendors limit this to 15 or 16.

  3. What STP feature disables a PortFast-enabled port when it receives a BPDU, protecting against accidental switch connections?

    Answer: BPDU Guard

    BPDU Guard err-disables a port upon receiving any BPDU, preventing switches from being connected to PortFast ports and disrupting the topology.

  4. Which spanning tree mode on Aruba switches is recommended for modern networks with multiple VLANs to provide per-VLAN load balancing?

    Answer: MSTP (802.1s)

    MSTP (802.1s) maps multiple VLANs to a smaller number of spanning tree instances, enabling per-group load balancing while reducing control plane overhead.

  5. A switch's root port has failed. In RSTP, which port transitions to Forwarding most quickly to restore connectivity?

    Answer: The Alternate port

    The RSTP Alternate port already holds a pre-computed alternate path to the root and can immediately transition to Forwarding when the root port fails, without waiting for timers.

  6. What is the effect of configuring 'spanning-tree port-type admin-edge' on an Aruba switch port?

    Answer: It enables PortFast behavior and suppresses TCNs on that port

    Configuring a port as admin-edge on Aruba switches enables PortFast-equivalent behavior, causing immediate Forwarding transition and suppressing topology change notifications.

  7. Which condition triggers Loop Guard to place an STP port into a loop-inconsistent state?

    Answer: BPDUs stop being received on a root or alternate port

    Loop Guard detects the loss of incoming BPDUs on a non-designated port and places it in loop-inconsistent (Blocking) state to prevent it from erroneously transitioning to Forwarding.