STP and Rapid PVST+ questions test your understanding of root bridge election, port roles, port states, and protection features. These appear in MCQ, multi-select, and drag-and-drop formats on the CCNA because STP behaviour is non-intuitive and frequently misunderstood.
Start Scenario PracticeDrag and drop the steps for the Spanning Tree Protocol (STP) convergence process in the correct order.
Explanation: STP elects a root bridge, then selects root and designated ports, blocking others to prevent loops.
Which TWO characteristics are true about the operation of Rapid PVST+? (Choose two.)
Explanation: Option C is correct because Rapid PVST+ supports the PortFast feature, which allows a switch port configured as an access port to transition immediately from the blocking state to the forwarding state, bypassing the listening and learning states. This is essential for ports connected to end hosts to avoid unnecessary STP convergence delays.
A network administrator is troubleshooting a performance issue in a large enterprise campus network. The network consists of Cisco Catalyst 9300 switches acting as access switches and Cisco Catalyst 9500 switches as distribution. Users on VLAN 10 report intermittent slow file transfers to a server on VLAN 20. The administrator has verified that there are no errors on the links, CPU utilization is normal, and STP topology is stable. The administrator suspects a possible QoS issue. Upon checking the QoS configuration on the access switch, the administrator finds that the default QoS configuration is in place, which trusts the CoS value at the port level. The connected devices are IP phones and PCs; the IP phones mark voice traffic with CoS 5. The server on VLAN 20 is connected to a distribution switch. Which action should the administrator take to most likely resolve the issue?
Explanation: Option C is correct because Auto QoS for VoIP automatically configures the necessary class maps, policy maps, and trust settings to properly classify and queue voice traffic (CoS 5) while ensuring data traffic is not starved. The default QoS configuration trusts CoS at the port level, but without proper queuing and scheduling, voice and data may compete for buffers, causing intermittent slow file transfers. Auto QoS sets up strict priority queuing for voice and allocates bandwidth for data, resolving the performance issue without manual misconfiguration.
Which TWO STP features are used to improve convergence time after a topology change?
Explanation: UplinkFast is correct because it enables a switch to immediately use an alternate root port when its current root port fails, bypassing the usual 30-second listening and learning delay. This is achieved by artificially lowering the bridge priority of the switch to trigger a topology change notification, allowing the backup port to transition directly to forwarding. BackboneFast is correct because it reduces convergence time by detecting indirect link failures in the backbone and allowing a switch to expire its Max Age timer (default 20 seconds) immediately, rather than waiting for the full timer to expire, thus speeding up the transition to a new root port.
Examine the following configuration snippet: interface GigabitEthernet1/0/1 switchport mode access switchport access vlan 100 spanning-tree portfast spanning-tree bpduguard enable What is the effect of this configuration?
Explanation: The configuration enables PortFast and BPDU Guard on an access port. PortFast immediately transitions the port to forwarding state, bypassing the usual STP listening and learning phases. BPDU Guard monitors for incoming BPDUs; if any are received, it error-disables the port to prevent a potential bridging loop from an unauthorized switch connection.
+10 more scenario questions available
Practice all Spanning Tree Protocol ScenariosSTP and Rapid PVST+ questions test your understanding of root bridge election, port roles, port states, and protection features. These appear in MCQ, multi-select, and drag-and-drop formats on the CCNA because STP behaviour is non-intuitive and frequently misunderstood. These appear throughout the 350-401 and require you to apply your knowledge, not just recall facts.
Cisco doesn't publish an exact breakdown, but scenario-based questions (especially exhibit and command-output formats) make up a significant portion of the 350-401. Practicing each scenario type ensures you're ready for any format.
Yes. Courseiva provides free 350-401 scenario practice across all official exam domains. The platform includes scenario-based questions, command-output interpretation, topic-based practice, mock exams, and readiness tracking — no account required.
Launch a full Spanning Tree Protocol Scenarios session with instant scoring and detailed explanations.
Start Scenario Practice →