Port Roles and States JN0-364 Practice Questions (Page 1)

Questions 1–5

1. 1application · medium

   A network administrator is reviewing the spanning-tree status on a switch and notices that a port previously in the forwarding state has transitioned to the blocking state. Which event would most likely cause this change?

   • AThe switch received a superior BPDU on that port, indicating a better path to the root bridge exists through another switch
   • BThe switch's root bridge priority was increased, making it more likely to become the root
   • CThe port received a TCN (Topology Change Notification) BPDU from a downstream switch
   • DThe port's link speed was manually changed from 1 Gbps to 100 Mbps
   Reveal Solution Discussion Select an answer first
2. 2foundation · easy

   What triggers a port in the blocking state to transition to the listening state in classic Spanning-Tree Protocol?

   • AThe port is elected as the root port or designated port
   • BThe port receives a configuration BPDU with the same root ID
   • CThe port's forward delay timer expires
   • DThe port receives a superior BPDU
   Reveal Solution Discussion Select an answer first
4. 3application · medium

   A Juniper switch running Spanning Tree Protocol (STP) has just been powered on. An engineer observes that interface ge-0/0/1 is in the listening state. What is the primary purpose of this state during the STP convergence process?

   • ATo listen for BPDUs and determine the port's role before it can forward traffic
   • BTo forward BPDUs and user data frames to all other ports on the switch
   • CTo immediately transition the port to the forwarding state if no BPDUs are received
   • DTo learn MAC addresses from incoming frames to populate the forwarding database
   Reveal Solution Discussion Select an answer first
5. 4expert · hard

   A network engineer is troubleshooting a spanning-tree convergence issue in a network running Rapid Spanning Tree Protocol (RSTP). A switch has just been connected to the network, and the engineer notices that a port that should be a designated port is taking longer than expected to transition to the forwarding state. The port is connected to a hub, and the engineer suspects that the port is not transitioning quickly because of the hub. Which RSTP feature is most likely causing the delay?

   • AThe port is in the listening state and must wait for the forward delay timer to expire before transitioning to learning
   • BThe port is not receiving a proposal from the hub, so it cannot use the proposal-agreement handshake to transition quickly
   • CThe port is receiving a superior BPDU from the hub, causing it to become an alternate port
   • DThe port is in the learning state and must wait for the forward delay timer to expire before transitioning to forwarding
   Reveal Solution Discussion Select an answer first
6. 5application · medium

   A network engineer is troubleshooting a loop in a bridged network running Rapid Spanning Tree Protocol (RSTP). On switch SW1, interface ge-0/0/3 is receiving superior BPDUs from a neighboring switch that is not the root bridge. The engineer wants to confirm that this interface is correctly preventing the loop. Which port role and state combination should the engineer expect to see on ge-0/0/3?

   • ADesignated role, forwarding state
   • BBackup role, learning state
   • CRoot role, forwarding state
   • DAlternate role, blocking state
   Reveal Solution Discussion Select an answer first