CCNPv8 ENCOR ( Version 8.0) – Chapters 1 – 5: L2 Redundancy Exam Answers Full 100% 2024

CCNPv8 ENCOR ( Version 8.0) – Chapters 1 – 5: L2 Redundancy Exam Answers Full 100% 2024

1. What is the goal of Layer 3 switching?

   • to process packets at Layer 2 switching speeds while utilizing the scalability of routing
   • to integrate all of the networking functions into one device
   • to provide a better path to the Internet without using routing protocols
   • to implement the routing process by using routed protocols
     

     Answers Explanation & Hints: Switches that perform Layer 3 switching process packets at Layer 2 hardware speeds while providing the scalability of routing.

2. Which two statements are true about routed ports on a multilayer switch? (Choose two.)

   • A routed port behaves like a regular router interface and supports VLAN subinterfaces.
   • A routed port is a physical switch port with Layer 2 capability.
   • A routed port is not associated with a particular VLAN.
   • To create a routed port requires removal of Layer 2 port functionality with the no switchport interface configuration command.
   • The interface vlan global configuration command is used to create a routed port.
     

     Answers Explanation & Hints: A switch routed port is a Layer 3 port that requires removal of Layer 2 port functionality with the no switchport interface configuration command. VLANs are associated with switch Layer 2 access and trunk ports.

3. Which two statements are true about the 802.1Q trunking protocol? (Choose two.)

   • Untagged frames will be placed in the configured native VLAN of a port.
   • It is a proprietary protocol that is supported on Cisco switches only.
   • Private VLAN configurations are not supported.
   • The native VLAN interface configurations must match at both ends of the link or frames could be dropped.
     

     Answers Explanation & Hints: 802.1Q is a standard trunking protocol where untagged frames are placed on the native VLAN. The native VLAN must be configured the same at both ends of the trunk link.

4. Which technology does CEF switching use on Cisco hardware-based routers to forward packets?

   • forwarding engines implemented in specialized ASICs
   • router general-purpose CPU
   • interVLAN routing using subinterfaces
   • route processors using stateful switchover
     

     Answers Explanation & Hints: CEF switching on Cisco hardware-based routers uses forwarding engines implemented in specialized ASICs to forward packets. Cisco software-based routers use the general-purpose CPU for packet switching. InterVLAN routing using subinterfaces is not a CEF technology, and route processors using stateful switchover is a redundancy technology used by routers.

5. What type of specialized memory is used to facilitate high performance switching in Cisco multilayer switches?

   • content-addressable memory (CAM)
   • ternary content addressable memory (TCAM)
   • address resolution protocol (ARP) memory
   • Cisco Express Forwarding (CEF) memory
     

     Answers Explanation & Hints: CAM is used by ARP to store MAC and IPv4 address pairs. CEF uses a FIB.

6. Which protocol is required for Cisco Express Forwarding to be able to successfully forward packets on a multilayer switch?

   • Cisco Discovery Protocol
   • Spanning Tree Protocol
   • Address Resolution Protocol
   • Dynamic Trunking Protocol
   • VLAN Trunking Protocol
     

     Answers Explanation & Hints: In order to forward packets, Cisco Express Forwarding (CEF) requires the MAC address of the next hop provided by ARP.

7. 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
     

     Answers Explanation & Hints: Spanning Tree Protocol (STP) is required to ensure correct network operation when designing a network with multiple interconnected Layer 2 switches or using redundant links to eliminate single points of failure between Layer 2 switches. Routing is a Layer 3 function and does not relate to STP. VLANs do reduce the number of broadcast domains but relate to Layer 3 subnets, not STP.

8. If left to default configuration settings, what will determine which switch becomes the spanning-tree root bridge in a Layer 2 domain?

   • the highest bridge priority
   • the highest management IP address
   • the lowest switch MAC address
   • the highest bridge ID
     

     Answers Explanation & Hints: By default, all switches will have the same priority value, so the election of the root bridge will be based on the lowest MAC address.

9. During the implementation of Spanning Tree Protocol, all switches are rebooted by the network administrator. What is the first step of the spanning-tree election process?

   • Each switch with a lower root ID than its neighbor will not send BPDUs.
   • All the switches send out BPDUs advertising themselves as the root bridge.
   • Each switch determines the best path to forward traffic.
   • Each switch determines what port to block to prevent a loop from occurring.
     

     Answers Explanation & Hints: After a Cisco switch boots, it will send out BPDUs containing its individual BID and the root ID for the network. By default, the initial root ID at bootup will be the ID of that individual switch. After a root bridge is elected, port states and paths are chosen.

10. After the election of the root bridge has been completed, how will switches find the best paths to the root bridge?

    • Each switch will analyze the sum of the hops to reach the root and use the path with the fewest hops.
    • Each switch will analyze the BID of all neighbors to reach the root and use the path through the lowest BID neighbors.
    • Each switch will analyze the port states of all neighbors and use the designated ports to forward traffic to the root.
    • Each switch will analyze the sum of all port costs to reach the root and use the path with the lowest cost.
      

      Answers Explanation & Hints: After the election of a root bridge has occurred, each switch will have to determine the best path to the root bridge from its location. The path is determined by summing the individual port costs along the path from each switch port to the root bridge.

11. Which statement is true about the port roles of the 802.1w Rapid Spanning Tree Protocol?

    • Ports are manually configured to be in the designated role.
    • An alternate or backup port can immediately change to a forwarding state without waiting for the network to converge.
    • Cisco-proprietary enhancements to the legacy 802.1D, such as UplinkFast and BackboneFast, are compatible with RSTP.
    • It takes an edge port 15 seconds to go from blocking to forwarding.
      

      Answers Explanation & Hints: In order to create a loop-free topology, 802.1w RSTP has the following port roles: root, designated, alternate, edge, and backup. RSTP is able to actively confirm that a port can safely transition to the forwarding state without having to rely on a timer configuration.

12. Which three components are combined to form a bridge ID?

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

      Answers Explanation & Hints: The three components that are combined to form a bridge ID are bridge priority, extended system ID, and MAC address.

13. 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
      

      Answers Explanation & Hints: Switches learn MAC addresses at the learning and forwarding port states. They receive and process BPDUs at the blocking, listening, learning, and forwarding port states.

14. 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
      

      Answers Explanation & Hints: Although the spanning-tree vlan 10 root primary command will ensure a switch will have a bridge priority value lower than other bridges introduced to the network, the spanning-tree vlan 10 priority 0 command ensures the bridge priority takes precedence over all other priorities.

15. Refer to the exhibit. The network has converged and Switch_6 has been elected root bridge of the STP tree. However, network traffic analysis indicates that Switch_1 would be a better root bridge. How can the network administrator make this change, assuming that the spanning-tree priorities are at the default settings?

    

    • Set the bridge priority of Switch_1 to 32,768.
    • Set the bridge priority of Switch_6 to 65,565.
    • Set the bridge priority of Switch_1 to 4,096.
    • Set the bridge priority of Switch_6 to 255.
      

      Answers Explanation & Hints: The switch priority is a value between 0-61,440 in increments of 4,096. Switch priority is initially set to 32,768 (the default). Therefore, Switch_1 can become the root bridge if the priority is set to a value between 0-28,672.

16. Why is it important that the network administrator consider the spanning-tree network diameter when choosing the root bridge?

    • The cabling distance between the switches is 100 meters.
    • The network diameter limitation is 9.
    • Convergence is slower as the BPDU travels away from the root.
    • BPDUs may be discarded because of expiring timers.
      

      Answers Explanation & Hints: The optional diameter keyword in the spanning-tree vlan vlan-id root {primary | secondary} [diameter diameter] command allows for tuning of the STP convergence. The diameter keyword should reference the maximum number of Layer 2 hops that a switch can be from the root bridge and modify the timers accordingly. The timers do not need to be modified on other switches because they are carried throughout the topology through the root bridge BPDUs.

17. A network administrator enters the spanning-tree portfast bpduguard default command. What is the result of this command being issued on a Cisco switch?

    • Any switch port will be error-disabled if it receives a BPDU.
    • Any trunk ports will be allowed to connect to the network immediately, rather than waiting to converge.
    • Any switch port that has been configured with PortFast will be error-disabled if it receives a BPDU.
    • Any switch port that receives a BPDU will ignore the BPDU message.
      

      Answers Explanation & Hints: The spanning-tree bpduguard default command will enable BPDU guard on all switch ports that have PortFast-enabled. This will put the port in an error-disabled state if a BPDU from another switch is received on a PortFast-enabled interface.

18. In what situation would a network administrator most likely implement root guard?

    • on all switch ports (used or unused)
    • on all switch ports that connect to host devices
    • on all switch ports that connect to another switch
    • on all switch ports that connect to a Layer 3 device
    • on all switch ports that connect to another switch that is not the root bridge
      

      Answers Explanation & Hints: Root guard in conjunction with PortFast, and BPDU guard is used to prevent an STP manipulation attack.

19. Which technology is used to protect the switched infrastructure from problems caused by receiving BPDUs on ports that should not be receiving them?

    • RSPAN
    • PortFast
    • Root guard
    • Loop guard
    • BPDU guard
      

      Answers Explanation & Hints: To form a single path through a Layer 2 network, Layer 2 devices communicate with one another by the use of bridge protocol data units (BPDUs) as part of the Spanning Tree Protocol (STP). An attacker manipulates STP by spoofing the root bridge so that a device that is controlled by the attacker becomes a root bridge. The attacker can then obtain more information about the network or networks. BPDU guard can be used on ports that connect to user devices that are configured with PortFast so that BPDUs will not be accepted through that port.

20. What are the two options that describe the effects of the spanning-tree portfast command? (Choose two.)

    • If the switch port is configured with PortFast, it waits 15 seconds before transitioning from a blocking to forwarding state.
    • Enabling PortFast on trunks that connect to other switches improves convergence.
    • If a switch port is configured with PortFast, it is an access port that immediately transitions from a blocking to forwarding state.
    • Portfast enables the port to bypass the listening and learning states of STP.
    • Portfast bypasses the learning state and moves immediately into blocking.
      

      Answers Explanation & Hints: The portfast feature is enabled on a specific access port with the spanning-tree portfast command. One of the benefits of the STP portfast feature, is that the access ports bypass the earlier 802.1D STP states (learning and listening) and forward traffic immediately.

21. Which statement describes the term root guard in the operation of STP?

    • It is a feature that prevents a configured port from becoming a root port.
    • It is a value that decides which switch can become the root bridge.
    • It is a safety mechanism that shuts down ports configured with STP portfast upon receipt of a BPDU.
    • It is a feature that prevents any alternative or root ports from becoming designated ports because of a loss of BPDUs on the root port.

    • Explanation & Hints: The statement that describes the term root guard in the operation of Spanning Tree Protocol (STP) is: It is a feature that prevents a configured port from becoming a root port. Root Guard is a security feature in the STP protocol designed to maintain the intended network topology by preventing switches connected to a port where Root Guard is enabled from becoming the root bridge. This is achieved by blocking the port from becoming a root port if a superior BPDU is received on that port. The purpose of Root Guard is to enforce the position of the root bridge in the network and prevent external switches or any changes in the network from altering the STP topology. When a Root Guard enabled port receives a superior BPDU, which could potentially make it a root port, the guard puts the port into a root-inconsistent state, effectively blocking all traffic except for STP BPDUs until the superior BPDUs cease. This mechanism ensures the stability and predictability of the network’s STP topology, safeguarding against unintended root bridge changes.

22. Which statement describes the term root bridge in the operation of STP?

    • It is a switch that is at the top of the spanning tree and whose ports are all forwarding and are all categorized as designated ports.
    • It is a safety mechanism that shuts down ports configured with STP portfast upon receipt of a BPDU.
    • It is a feature that prevents any alternative or root ports from becoming designated ports because of a loss of BPDUs on the root port.
    • It is a value that decides which switch can become the root bridge.

    • Explanation & Hints: The statement that describes the term root bridge in the operation of STP is: It is a switch that is at the top of the spanning tree and whose ports are all forwarding and are all categorized as designated ports. Explanation: The root bridge in Spanning Tree Protocol (STP) is the central reference point in the STP topology from which all path costs are calculated. It is selected through a network-wide election process based on the lowest bridge ID, which combines the priority value and the MAC address of the switch. Once elected, the root bridge serves as the top of the spanning tree, and all paths in the network are determined based on their distance to the root bridge. All active ports on the root bridge are designated ports, and they are in a forwarding state, ensuring that there are no loops in the network topology and that all segments of the network can communicate with each other. The role of the root bridge is crucial for the stable operation and efficiency of the STP network.

23. Which statement describes the term root bridge in the operation of STP?

    • It is a switch that is at the top of the spanning tree and whose ports are all forwarding and are all categorized as designated ports.
    • It is a safety mechanism that shuts down ports configured with STP portfast upon receipt of a BPDU.
    • It is a value that is used, in the event of a loop, to decide which port on the switch must be put into forwarding state.
    • It is a value that decides which switch can become the root bridge.

    • Explanation & Hints: The statement that describes the term root bridge in the operation of STP (Spanning Tree Protocol) is: It is a switch that is at the top of the spanning tree and whose ports are all forwarding and are all categorized as designated ports. Explanation: The root bridge in the context of Spanning Tree Protocol is the central point in the network topology for STP calculations. It is chosen based on the lowest bridge ID among all switches participating in the STP domain. The bridge ID is a combination of a priority value and the MAC address of the switch. Once elected, the root bridge’s role is pivotal as it essentially becomes the logical center of the spanning tree for that particular network segment. All of its operational ports are placed in a forwarding state, meaning they can send and receive network traffic, and these ports are designated as designated ports. This ensures optimal routing of data packets within the network, minimizing the potential for loops and ensuring efficient use of network resources.

24. Which statement describes the term bridge priority in the operation of STP?

    • It is a value that decides which switch can become the root bridge.
    • It is a value that is used, in the event of a loop, to decide which port on the switch must be put into forwarding state.
    • It is a safety mechanism that shuts down ports configured with STP portfast upon receipt of a BPDU.
    • It is a feature that prevents any alternative or root ports from becoming designated ports because of a loss of BPDUs on the root port.

    • Explanation & Hints: The statement that describes the term bridge priority in the operation of STP (Spanning Tree Protocol) is: It is a value that decides which switch can become the root bridge. Explanation: Bridge priority is a component of the bridge ID used in STP to elect the root bridge. The bridge ID consists of a bridge priority value and the MAC address of the switch. The switch with the lowest bridge ID (which considers both the priority and MAC address) becomes the root bridge in the spanning tree topology. The default priority value can be adjusted to influence which switch is more likely to be elected as the root bridge, allowing network administrators to control the layout of the spanning tree for efficiency and optimization of network traffic.

25. Which statement describes the term bridge priority in the operation of STP?

    • It is a value that decides which switch can become the root bridge.
    • It is a value that is used, in the event of a loop, to decide which port on the switch must be put into forwarding state.
    • It is a safety mechanism that shuts down ports configured with STP portfast upon receipt of a BPDU.
    • It is a feature that allows access ports to bypass the earlier learning and listening states and forward traffic immediately.

    • Explanation & Hints: The statement that accurately describes the term bridge priority in the operation of STP (Spanning Tree Protocol) is: It is a value that decides which switch can become the root bridge. Explanation: Bridge priority is a crucial parameter in the Spanning Tree Protocol that plays a key role in the root bridge election process. Each switch participating in STP has a bridge priority, a numerical value that, combined with the switch’s MAC address, forms the bridge ID. When STP is determining which switch should be the root bridge of the spanning tree, it compares the bridge IDs of all switches in the network. The switch with the lowest bridge ID, which includes the lowest combination of bridge priority and MAC address, is elected as the root bridge. Adjusting the bridge priority on a switch allows network administrators to influence which switch becomes the root bridge, enabling them to optimize the network’s topology and ensure efficient data paths.

26. Which statement describes the term forwarding in the operation of STP?

    • It is a port state that can forward all network traffic and can update the MAC address table.
    • It is a port state that is enabled but does not forward any traffic to ensure that a loop does not occur.
    • It indicates that the port has transitioned from a blocking state and can send or receive BPDUs, but cannot forward any other network traffic.
    • It is a port state that can modify the MAC address table with any network traffic that it receives, but only forwards BPDUs and not any other network traffic

    • Explanation & Hints: The statement that describes the term forwarding in the operation of STP (Spanning Tree Protocol) is: It is a port state that can forward all network traffic and can update the MAC address table. Explanation: In STP operation, the forwarding state is the ultimate operational state a port can be in where it actively participates in data forwarding. In this state, a port can send and receive all types of network traffic, including user data frames and STP Bridge Protocol Data Units (BPDUs). Additionally, the port can learn MAC addresses from incoming traffic and update the MAC address table accordingly. This state is critical for the normal operation of a network, allowing for the efficient delivery of frames across the switched network while preventing loops that STP is designed to avoid.

27. Which statement describes the term blocking in the operation of STP?

    • It is a port state that is enabled but does not forward any traffic to ensure that a loop does not occur.
    • It indicates that the port is in an administratively off position.
    • It indicates that the port has transitioned from a blocking state and can send or receive BPDUs, but cannot forward any other network traffic.
    • It is a port state that can modify the MAC address table with any network traffic that it receives, but only forwards BPDUs and not any other network traffic.

    • Explanation & Hints: The statement that describes the term blocking in the operation of STP (Spanning Tree Protocol) is: It is a port state that is enabled but does not forward any traffic to ensure that a loop does not occur. Explanation: In STP operation, the blocking state is used to prevent network loops by stopping data frames from being forwarded through a port, while still allowing the port to receive BPDU frames. Ports in the blocking state do not participate in frame forwarding, nor do they learn MAC addresses, thus effectively preventing the formation of loops in the network. This state is critical in the STP algorithm, ensuring that only one active path exists between any two nodes in the network, while redundant paths are put into a blocking state until they are needed due to a topology change.

28. Which statement describes the term blocking in the operation of STP?

    • It is a port state that is enabled but does not forward any traffic to ensure that a loop does not occur.
    • It indicates that the port is in an administratively off position.
    • It is a port state that can forward all network traffic and can update the MAC address table.
    • It is a port state that discards all packets because the switch has detected a configuration or an operational problem on that port.

    • Explanation & Hints: The statement that describes the term blocking in the operation of STP (Spanning Tree Protocol) is: It is a port state that is enabled but does not forward any traffic to ensure that a loop does not occur. Explanation: In the context of STP, the blocking state is crucial for preventing network loops. A port in the blocking state is still active (i.e., physically operational) but is instructed not to forward any user data frames. It can, however, listen to and process BPDU (Bridge Protocol Data Units) messages, which are essential for the STP to monitor network topology changes. This state ensures that redundant paths in a network are put into a non-forwarding state to prevent loops, while still allowing the switch to receive network topology information through BPDUs.

29. Which statement describes the term root port in the operation of STP?

    • It is a port that connects to the root bridge or an upstream switch in the spanning-tree topology.
    • It is a port state that can modify the MAC address table with any network traffic that it receives, but only forwards BPDUs and not any other network traffic.
    • It indicates that the port has transitioned from a blocking state and can send or receive BPDUs, but cannot forward any other network traffic.
    • It is a port state that can forward all network traffic and can update the MAC address table.

    • Explanation & Hints: The statement that describes the term root port in the operation of STP (Spanning Tree Protocol) is: It is a port that connects to the root bridge or an upstream switch in the spanning-tree topology. Explanation: In the context of STP, each non-root bridge must have a single root port. The root port is the port on the switch that has the lowest cost path to the root bridge. It is through this port that the switch has its best path to the root bridge in the spanning tree topology. The root port is always in a forwarding state if the switch is not the root bridge itself, allowing it to forward traffic towards the root bridge. This port plays a crucial role in ensuring loop-free and efficient paths for network traffic within the spanning tree topology.

30. Which statement describes the term root port in the operation of STP?

    • It is a port that connects to the root bridge or an upstream switch in the spanning-tree topology.
    • It is a port state that can modify the MAC address table with any network traffic that it receives, but only forwards BPDUs and not any other network traffic.
    • It indicates that the port has transitioned from a blocking state and can send or receive BPDUs, but cannot forward any other network traffic.
    • It is a port that receives and forwards BPDU frames, provides connectivity to downstream devices and switches, and only one should be active per link.

    • Explanation & Hints: The statement that accurately describes the term root port in the operation of STP (Spanning Tree Protocol) is: It is a port that connects to the root bridge or an upstream switch in the spanning-tree topology. Explanation: The root port is the port on a non-root switch that has the best path (lowest cost) to the root bridge in a spanning tree topology. It is a critical component of the STP algorithm, which ensures a loop-free network topology by establishing a single active path to the root bridge for each switch. The root port is determined through the exchange of BPDU (Bridge Protocol Data Units) frames and is always in a forwarding state, enabling it to transmit and receive network traffic as part of the active topology. The designation of a root port is essential for maintaining the hierarchy and structure of the spanning tree, ensuring efficient and loop-free forwarding of frames within an Ethernet network.

31. What are two configuration parameters that must match for all switches in the same MST region? (Choose two.)

    • port status
    • region name
    • bridge priority
    • version number
    • trunk link encapsulation method
      

      Answers Explanation & Hints: The mst version number and region name must match for all switches in the same MST region. These parameters can be adjusted through MST configuration.

32. Assuming that all switches in a network have the default bridge priority for each MST instance, what effect does the command spanning-tree mst 10 root seconday have when entered on a single switch?

    • sets the bridge priority on the switch to 24586 for MST instance 10
    • sets the bridge priority on the switch to 24576 for MST instance 10
    • sets the bridge priority on the switch to 28672 for MST instance 10
    • sets the bridge priority on the switch to 24582 for MST instance 10
      

      Answers Explanation & Hints: In MST configuration, an MST instance priority can be defined in one of two methods: spanning-tree mst instance-number priority priority , where the priority is a value between 0 and 61,440, in increments of 4096 spanning-tree mst instance-number root { primary | secondary }[ diameter diameter ], where the primary keyword sets the priority to 24,576, and the secondary keyword sets the priority to 28,672

33. Which two statements describe the MST internal spanning tree instance? (Choose two)

    • It is always instance 0.
    • It carries all VLANs traffic.
    • It runs on all switch port interfaces of switches in the MST region.
    • It carries identical setup information among interconnected MST regions.
    • It runs on all switch port interfaces of switches that are designated as root bridges.
      

      Answers Explanation & Hints: MST uses a special STP instance called the internal spanning tree (IST), which is always the first instance, instance 0. The IST runs on all switch port interfaces for switches in the MST region, regardless of the VLANs associated with the ports.

34. Refer to the exhibit. A network administrator issues the show spanning-tree command to verify the MST configuration. Which two conclusions can be drawn based on the output? (Choose two.)

    

    • SW1 is the root bridge for instance 1.
    • SW1 is running IEEE 802.1S protocol.
    • SW1 is running IEEE 802.1W STP protocol.
    • PortFast is enabled on ports Gi1/0/2 and Gi1/0/3.
    • The command spanning-tree mst 1 root secondary was entered.
      

      Answers Explanation & Hints: SW1 is running MST, which is IEEE 802.1S standard. IEEE 802.1W is the standard for RSTP. SW1 is the root bridge for instance 1. The instance 1 priority is set as 24576. If it is set through the secondary keyword, it would be 28672. If the portfast feature is enabled on a port, the port type would be P2p Edge.

35. Refer to the exhibit. A network administrator is configuring MST tuning on SW1. The objective is to change the path cost value of the interface Gi1/0/1 to represent a higher-speed bandwidth link. Which value could be used in the command spanning-tree mst 0 cost for this task?

    

    • 0
    • 1
    • 24576
    • 32768
      

      Answers Explanation & Hints: As shown in the output, the interface STP cost is derived from the media speed of the interface using the long-mode method. Using this method, the range of the interface path cost is from 1 to 200000000. A lower path cost represents higher-speed transmission bandwidth.

36. What are two misconfigurations within an MST region that might introduce port blocking unintentionally? (Choose two.)

    • trunk link pruning
    • VLAN assignment to the IST
    • too many VLANs assigned to an instance
    • misconfigured region name across the MST region
    • misconfigured revision number across the MST region
      

      Answers Explanation & Hints: VLAN assignment to the IST and trunk link pruning are two common misconfigurations within the MST region. A misconfigured region name or misconfigured revision number will cause the failure in forming the MST region.

37. How does an MST region send VLAN information through the PVST simulation mechanism to a switch that runs PVST+?

    • It sends out one PVST+ BPDU that maps all VLANs into VLAN1.
    • It sends out one PVST+ BPDU with the information from the IST.
    • It sends out multiple PVST+ BPDUs, one for each VLAN, plus the IST.
    • It sends out PVST+ BPDUs, one for each VLAN, using the information from the IST.
      

      Answers Explanation & Hints: The PVST simulation mechanism sends out PVST+ including RSTP BPDUs, one for each VLAN, using the information derived from the internal spanning tree (IST). This requires a mapping of one topology in IST to multiple VLANs toward the PVST link.

38. Which two VTP modes allow for the creation, modification, and deletion of VLANs on the local switch? (Choose two.)

    • client
    • slave
    • server
    • transparent
    • master
    • distribution
      

      Answers Explanation & Hints: The three VTP modes are server, client, and transparent. In server VTP mode, the switch can create, modify, and delete VLANs and send this information on to other switches that are in the same VTP domain. Switches in transparent VTP mode can do the same except that information is not transmitted to other switches.

39. The network administrator wants to configure a switch to pass VLAN update information to other switches in the domain but not update its own local VLAN database. Which two steps should the administrator perform to achieve this? (Choose two.)

    • Reset the VTP counters.
    • Configure VTP version 1 on the switch.
    • Configure the VTP mode of the switch to transparent.
    • Verify that the switch has a higher configuration revision number.
    • Configure the switch with the same VTP domain name as other switches in the network.
      

      Answers Explanation & Hints: Besides the VTP domain name and mode needing to be configured, the switch must connect to other switches in the same VTP domain through a trunk in order to transmit/receive VTP information.

40. Refer to the exhibit. Access1 is a new switch that is to be connected as a VTP client to the network once it has been configured. Given the output generated by the VTP server switch Dist-2, which series of configuration commands would successfully introduce the client switch into the VTP domain?

    

    • Access1(config)# vtp mode client
      Access1(config)# vtp domain mycorp
      Access1(config)# vtp password ITrustYou
    • Access1(config)# vtp mode client
      Access1(config)# vtp domain MYCORP
      Access1(config)# vtp version 2
      Access1(config)# vtp password ITrustYou
    • Access1(config)# vtp mode client
      Access1(config)# vtp domain mycorp
      Access1(config)# vtp password ITrustYou
    • Access1(config)# vtp mode client
      Access1(config)# vtp domain Mycorp
      Access1(config)# vtp version 2
      Access1(config)# vtp password ITrustYou

      Answers Explanation & Hints: VTP domain names are case sensitive.

41. Given the following configuration, which two statements are true? (Choose two.)

    switch(vlan)# vtp version 2
    switch(vlan)# vtp mode server
    switch(vlan)# vtp domain Cisco
    switch(vlan)# vtp password mypassword

    • This switch can create, modify, and delete all VLANs within the Cisco domain.
    • This switch maintains a full list of all VLANs and can create VLANs, but cannot delete or modify existing VLANs.
    • The password will prevent unauthorized routers from participating in the Cisco domain.
    • This switch can advertise its VLAN configuration to other switches in the Cisco domain only, but can receive advertisements from other domains.
    • This switch can send and receive advertisements from only the Cisco domain.
      

      Answers Explanation & Hints: A switch in VTP server mode can create, modify, and delete VLANs as well as transmit that information (if the switch has the highest VTP configuration revision number) to other switches in the same VTP domain.

42. Which Cisco proprietary protocol is used for dynamically forming a trunk connection between two switches?

    • STP
    • PAgP
    • DTP
    • VTP
      

      Answers Explanation & Hints: Dynamic Trunking Protocol (DTP) is a Cisco proprietary protocol used for dynamically negotiating a trunk connection between two Cisco switches.

43. Which two DTP mode combinations will form a trunk link between two switches? (Choose two.)

    • dynamic auto and dynamic auto
    • trunk and access
    • trunk and dynamic desirable
    • dynamic auto and dynamic desirable
    • access and dynamic auto
      

      Answers Explanation & Hints: There are five DTP mode combinations that will result in successful trunk link negotiation between two switches.dynamic auto and dynamic desirable dynamic desirable and dynamic desirable trunk and trunk trunk and dynamic auto trunk and dynamic desirable

44. Which is a characteristic of EtherChannel?

    • EtherChannel uses physical ports that have been upgraded to provide a faster connection.
    • STP will not block redundant EtherChannel bundles between two switches.
    • STP treats all interfaces in an EtherChannel bundle as a single logical link.
    • EtherChannel configuration is applied to each physical port.
      

      Answers Explanation & Hints: Because EtherChannel creates one logical link out of a number of physical ports, STP will treat the one logical link as an individual connection. When a physical port that is part of the logical link fails, the link will stay active and STP will not recalculate.

45. Which LACP technology can identify and remove a LACP enabled link from an EtherChannel within three seconds when the link is experiencing connectivity issues?

    • LACP fast
    • LACP port priority
    • LACP system priority
    • LACP min-links
      

      Answers Explanation & Hints: LACP fast advertises an LACP packet every second and after three seconds of not receiving an LACP packet, removes the link from the EtherChannel bundle. LACP port priority allows an LACP enabled switch to select which member interfaces are active within a port-channel that has more member interfaces than the maximum allowed. LACP system priority allows an LACP enabled switch to be designated as the master switch for a port-channel. LACP min-links is used to configure a required minimum number of physical connections that must be active in order for the EtherChannel to stay active.

46. Which LACP technology is used for designating a specific number of member interfaces that must remain active in order for the EtherChannel bundle to be usable?

    • LACP system priority
    • LACP min-links
    • LACP fast
    • LACP port priority
      

      Answers Explanation & Hints: LACP fast advertises an LACP packet every second and after three seconds of not receiving an LACP packet, removes the link from the EtherChannel bundle. LACP port priority allows an LACP enabled switch to select which member interfaces are active within a port-channel that has more member interfaces than the maximum allowed. LACP system priority allows an LACP enabled switch to be designated as the master switch for a port-channel. LACP min-links is used to configure a required minimum number of physical connections that must be active in order for the EtherChannel to stay active.

47. Which LACP technology is used for designating which member interfaces will be active in a port-channel configuration where there are more member interfaces than the maximum allowed?

    • LACP port priority
    • LACP system priority
    • LACP fast
    • LACP min-links
      

      Answers Explanation & Hints: LACP fast advertises an LACP packet every second and after three seconds of not receiving an LACP packet, removes the link from the EtherChannel bundle. LACP port priority allows an LACP enabled switch to select which member interfaces are active within a port-channel that has more member interfaces than the maximum allowed. LACP system priority allows an LACP enabled switch to be designated as the master switch for a port-channel. LACP min-links feature is used to configure a required minimum number of physical connections that must be active in order for the EtherChannel to stay active.

48. Refer to the exhibit. The administrator tried to create an EtherChannel between S1 and the other two switches via the commands that are shown, but was unsuccessful. What is the problem?

    

    • Traffic can only be sent to two different switches if EtherChannel is implemented on Gigabit Ethernet interfaces.​
    • Traffic can only be sent to two different switches if EtherChannel is implemented on Layer 3 switches.​
    • Traffic cannot be sent to two different switches through the same EtherChannel link.
    • Traffic cannot be sent to two different switches, but only to two different devices like an EtherChannel-enabled server and a switch.​
      

      Answers Explanation & Hints: An EtherChannel link can only be created between two switches or between an EtherChannel-enabled server and a switch. Traffic cannot be sent to two different switches through the same EtherChannel link.

49. Refer to the exhibit. An EtherChannel was configured between switches S1 and S2, but the interfaces do not form an EtherChannel. What is the problem?

    

    • The interface port-channel number has to be different on each switch.
    • The switch ports were not configured with speed and duplex mode.
    • The switch ports have to be configured as access ports with each port having a VLAN assigned.​
    • The EtherChannel was not configured with the same allowed range of VLANs on each interface.
      

      Answers Explanation & Hints: The guidelines for configuring an EtherChannel link are as follows:Interfaces which form an EtherChannel can be physically discontiguous, and on different modules. Interfaces in an EtherChannel have to operate at the same speed and in the same duplex mode. Interfaces in the EtherChannel must be assigned to the same VLAN, or be configured as a trunk. Interfaces in the EtherChannel have to support the same allowed range of VLANs.