Cisco CCNA 3 Chapter 3 version 6.0 Exam Answers

1. 1. Question

   Which two network design features require Spanning Tree Protocol (STP) to ensure correct network operation? (Choose two.)

   •  static default routes
   •  implementing VLANs to contain broadcasts
   •  redundant links between Layer 2 switches
   •  link-state dynamic routing that provides redundant routes
   •  removing single points of failure with multiple Layer 2 switches

2. 2. Question

   What is the outcome of a Layer 2 broadcast storm?

   •  Routers will take over the forwarding of frames as switches become congested.
   •  New traffic is discarded by the switch because it is unable to be processed.
   •  CSMA/CD will cause each host to continue transmitting frames.
   •  ARP broadcast requests are returned to the transmitting host.

3. 3. Question

   What is the purpose of the Spanning Tree Protocol (STP)?

   •  prevents Layer 2 loops
   •  prevents routing loops on a router
   •  creates smaller collision domains
   •  creates smaller broadcast domains
   •  allows Cisco devices to exchange routing table updates

4. 4. Question

   What is a characteristic of a Layer 2 loop?

   •  Broadcast frames are forwarded back to the sending switch.
   •  The Time-to-Live attribute of a frame is set to infinity.
   •  Routers continually forward packets to other routers.
   •  A switch is continually forwarding the same unicast frame.

5. 5. Question

   What additional information is contained in the 12-bit extended system ID of a BPDU?

   •  MAC address
   •  VLAN ID
   •  IP address
   •  port ID

6. 6. Question

   Which three components are combined to form a bridge ID?

   •  port ID
   •  IP address
   •  extended system ID
   •  MAC address
   •  bridge priority
   •  cost

7. 7. Question

   Refer to the exhibit. Which switch will be elected the root bridge and which switch will place a port in blocking mode? (Choose two.)

   

   CCNA3 v6.0 Chapter 3 Exam 03

   •  SW1 will become the root bridge.
   •  SW2 will become the root bridge.
   •  SW2 will get a port blocked.
   •  SW4 will get a port blocked.
   •  SW3 will become the root bridge.
   •  SW4 will become the root bridge.

8. 8. Question

   Refer to the exhibit. Which trunk link will not forward any traffic after the root bridge election process is complete?

   

   CCNA3 v6.0 Chapter 3 Exam 01

   •  Trunk1
   •  Trunk2
   •  Trunk3
   •  Trunk4

9. 9. Question

   Which protocol provides up to 16 instances of RSTP, combines many VLANs with the same physical and logical topology into a common RSTP instance, and provides support for PortFast, BPDU guard, BPDU filter, root guard, and loop guard?

   •  STP
   •  Rapid PVST+
   •  PVST+
   •  MST

10. 10. Question

    Which Cisco switch feature ensures that configured switch edge ports do not cause Layer 2 loops if a port is mistakenly connected to another switch?

    •  BPDU guard
    •  extended system ID
    •  PortFast
    •  PVST+

11. 11. Question

    Which two types of spanning tree protocols can cause suboptimal traffic flows because they assume only one spanning-tree instance for the entire bridged network? (Choose two.)

    •  STP
    •  Rapid PVST+
    •  PVST+
    •  MSTP
    •  RSTP

12. 12. Question

    Which spanning tree standard supports only one root bridge so that traffic from all VLANs flows over the same path?

    •  Rapid PVST
    •  802.1D
    •  MST
    •  PVST+

13. 13. Question

    What is an advantage of PVST+?

    •  PVST+ requires fewer CPU cycles for all the switches in the network.
    •  PVST+ reduces bandwidth consumption compared to traditional implementations of STP that use CST.
    •  PVST+ optimizes performance on the network through autoselection of the root bridge.
    •  PVST+ optimizes performance on the network through load sharing.

14. 14. Question

    In which two port states does a switch learn MAC addresses and process BPDUs in a PVST network? (Choose two.)

    •  blocking
    •  disabled
    •  forwarding
    •  learning
    •  listening

15. 15. Question

    If no bridge priority is configured in PVST, which criteria is considered when electing the root bridge?

    •  lowest IP address
    •  lowest MAC address
    •  highest IP address
    •  highest MAC address

16. 16. Question

    Which RSTP ports are connected to end devices?

    •  trunk ports
    •  designated ports
    •  root ports
    •  edge ports

17. 17. Question

    A network administrator is preparing the implementation of Rapid PVST+ on a production network. How are the Rapid PVST+ link types determined on the switch interfaces?

    •  Link types are determined automatically.
    •  Link types must be configured with specific port configuration commands.
    •  Link types can only be determined if PortFast has been configured.
    •  Link types can only be configured on access ports configured with a single VLAN.

18. 18. Question

    Which port state will switch ports immediately transition to when configured for PortFast?

    •  listening
    •  learning
    •  forwarding
    •  blocking

19. 19. Question

    Which STP priority configuration would ensure that a switch would always be the root switch?

    •  spanning-tree vlan 10 priority 0
    •  spanning-tree vlan 10 priority 61440
    •  spanning-tree vlan 10 root primary
    •  spanning-tree vlan 10 priority 4096

20. 20. Question

    Refer to the exhibit. What is the role of the SW3 switch?

    

    CCNA3 v6.0 Chapter 3 Exam 02

    •  designated switch
    •  edge switch
    •  root bridge
    •  enabled bridge
    •  local bridge

21. 21. Question

    To obtain an overview of the spanning tree status of a switched network, a network engineer issues the show spanning-tree command on a switch. Which two items of information will this command display? (Choose two.)

    •  The root bridge BID.
    •  The role of the ports in all VLANs.
    •  The status of native VLAN ports.
    •  The number of broadcasts received on each root port.
    •  The IP address of the management VLAN interface.

22. 22. Question

    What port type is used to interconnect switches in a switch stack?

    •  StackWise
    •  root
    •  designated
    •  edge

23. 23. Question

    Match the spanning-tree feature with the protocol type. (Not all options are used.)

    • 
      

      CCNA2 v6.0 Chapter 3 Exam 01

24. 24. Question

    Fill in the blank. Do not use abbreviations.
    The spanning-tree       mode rapid-pvst         global configuration command is used to enable Rapid PVST+.

25. 25. Question

    Open the PT Activity. Perform the tasks in the activity instructions and then answer the question.
    Which switch is the root bridge?​

    •  Switch_1
    •  Switch_2
    •  Switch_3
    •  Switch_4