CCNA3 ScaN v6.0 Chapter 4 Exam Answers 2018 2019

Last Updated on March 15, 2019 by Admin

CCNA3 v6.0 Chapter 4 Exam Answers 2018 2019 Full 100%

1. Refer to the exhibit. Which switching technology would allow each access layer switch link to be aggregated to provide more bandwidth between each Layer 2 switch and the Layer 3 switch?

   

   CCNA3 v6.0 Chapter 4 Exam 007

   •  HSRP
   •  PortFast
   •  trunking
   •  EtherChannel

   Explanation: PortFast is used to reduce the amount of time that a port spends going through the spanning-tree algorithm, so that devices can start sending data sooner. Trunking can be implemented in conjunction with EtherChannel, but trunking alone does not aggregate switch links. HSRP is used to load-balance traffic across two different connections to Layer 3 devices for default gateway redundancy. HSRP does not aggregate links at either Layer 2 or Layer 3 as EtherChannel does.

2. Which statement is true regarding the use of PAgP to create EtherChannels?
   •  It requires full duplex.
   •  It is Cisco proprietary.
   •  It requires more physical links than LACP does.
   •  It increases the number of ports that are participating in spanning tree.
   •  It mandates that an even number of ports (2, 4, 6, etc.) be used for aggregation.

   Explanation: PAgP is used to automatically aggregate multiple ports into an EtherChannel bundle, but it only works between Cisco devices. LACP can be used for the same purpose between Cisco and non-Cisco devices. PAgP must have the same duplex mode at both ends and can use two ports or more. The number of ports depends on the switch platform or module. An EtherChannel aggregated link is seen as one port by the spanning-tree algorithm.

3. Which two protocols are used to implement EtherChannel? (Choose two.)

   •  Spanning Tree Protocol
   •  Rapid Spanning Tree Protocol
   •  Port Aggregation Protocol
   •  Link Aggregation Control Protocol
   •  Cisco Discovery Protocol

   Explanation: Port Aggregation Protocol and Link Aggregation Control Protocol are used to implement EtherChannel. Spanning Tree and Rapid Spanning Tree Protocol are used to prevent switching loops. Cisco Discovery Protocol is Cisco-proprietary and is used to discovery information about adjacent Cisco devices such as model number and IP address.

4. Which statement describes a characteristic of EtherChannel?
   •  It can combine up to a maximum of 4 physical links.
   •  It can bundle mixed types of 100 Mb/s and 1Gb/s Ethernet links.
   •  It consists of multiple parallel links between a switch and a router.
   •  It is made by combining multiple physical links that are seen as one link between two switches.

   Explanation: An EtherChannel is formed by combining multiple (same type) Ethernet physical links so they are seen and configured as one logical link. It provides an aggregated link between two switches. Currently each EtherChannel can consist of up to eight compatibly configured Ethernet ports.

5. Which statement describes an EtherChannel implementation?
   •  EtherChannel operates only at Layer 2.
   •  PAgP cannot be used in conjunction with EtherChannel.
   •  A trunked port can be part of an EtherChannel bundle.
   •  EtherChannel can support up to a maximum of ten separate links.

   Explanation: Up to 16 links can be grouped in an EtherChannel by using the the PAgP or LACP protocol. EtherChannel can be configured as a Layer 2 bundle or a Layer 3 bundle. Configuring a Layer 3 bundle is beyond the scope of this course. If a trunked port is a part of the EtherChannel bundle, all ports in the bundle need to be trunk ports and the native VLAN must be the same on all of these ports. A best practice is to apply the configuration to the port channel interface. The configuration is then automatically applied to the individual ports.

6. An EtherChannel link using LACP was formed between two switches, S1 and S2. While verifying the configuration, which mode combination could be utilized on both switches?​
   •  S1-on and S2-passive
   •  S1-passive and S2-passive​
   •  S1-on and S2-active​
   •  S1-passive and S2-active

   Explanation: An EtherChannel link will be formed using LACP when both switches are in on mode or in active mode, or when one of them is in passive mode and the other is in active mode.

7. What is an advantage of using LACP?
   •  increases redundancy to Layer 3 devices
   •  decreases the chance of a spanning-tree loop
   •  allows automatic formation of EtherChannel links
   •  provides a simulated environment for testing link aggregation
   •  decreases the amount of configuration that is needed on a switch for EtherChannel
8. What is a best practice to use before beginning an EtherChannel implementation?
   •  Assign affected interfaces to VLAN 1.
   •  Assign affected interfaces to the management VLAN.
   •  Shut down each of the affected interfaces.
   •  Enable each of the affected interfaces.
   •  Assign affected interfaces to an unused VLAN.

   Explanation: Before configuring EtherChannel, the interfaces used should be shut down so that any incomplete configuration will not cause activity on the link.

9. Which PAgP mode combination will establish an EtherChannel?

   •  switch 1 set to on; switch 2 set to desirable.
   •  switch 1 set to desirable; switch 2 set to desirable.​
   •  switch 1 set to auto; switch 2 set to auto.​
   •  switch 1 set to auto; switch 2 set to on.​

   Explanation: Switch 1 and switch 2 will establish an EtherChannel if both sides are set to desirable as both sides will negotiate the link. A channel can also be established if both sides are set to on, or if one side is set to auto and the other to desirable. Setting one switch to on will prevent that switch from negotiating the formation of an EtherChannel bundle.

10. Which three options must match in order to establish an EtherChannel between two directly connected switches? (Choose three.)
    •  port numbers that are used for the EtherChannel
    •  VLAN memberships of the interfaces that are used for EtherChannel
    •  domain names on the switches
    •  speed of the interfaces that are used for EtherChannel
    •  duplex settings of the interfaces that are used for EtherChannel
    •  port security settings on the interfaces that used for EtherChannel

    Explanation: Speed and duplex settings must match for all interfaces in an EtherChannel. All interfaces in the EtherChannel must be in the same VLAN if the ports are not configured as trunks. Any ports may be used to establish an EtherChannel. Domain names and port security settings are not relevant to EtherChannel.

11. A network administrator is configuring an EtherChannel link between switches SW1 and SW2 by using the command SW1(config-if-range)# channel-group 1 mode passive. Which command must be used on SW2 to enable this EtherChannel?
    •  SW2(config-if-range)# channel-group 1 mode auto
    •  SW2(config-if-range)# channel-group 1 mode active
    •  SW2(config-if-range)# channel-group 1 mode passive
    •  SW2(config-if-range)# channel-group 1 mode desirable

    Explanation: The possible combinations to establish an EtherChannel between SW1 and SW2 using LACP or PAgP are as follows: PAgP on on auto desirable desirable desirable LACP on on active active passive active The EtherChannel mode chosen on each side of the EtherChannel must be compatible in order to enable it.

12. 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?

    

    CCNA3 v6.0 Chapter 4 Exam 008

    •  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.

    Explanation:  The guidelines for configuring an EtherChannel link are: 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.

13. Refer to the exhibit. A network administrator has decided that an EtherChannel between ports 0/1 and 0/2 on switches S1 and S2 would help performance. After making the configuration, the administrator notices no performance gain. Based on the output that is shown, what two possible assumptions could a network administrator make? (Choose two.)

    

    CCNA3 v6.0 Chapter 4 Exam 006

    •  The EtherChannel bundle is working.
    •  The EtherChannel bundle is not working.
    •  One of the ports on S2 was not configured correctly.
    •  Switch S2 did not use a compatible EtherChannel mode.
    •  LACP and PAgP were both used to form the EtherChannel.
    •  Switch S2 must be configured so that the maximum number of port channels is increased.

    Explanation: In order to form an EtherChannel, all ports should be within the same group.

14. Refer to the exhibit. A network administrator issued the show etherchannel summary command on the switch S1. What conclusion can be drawn?

    

    CCNA3 v6.0 Chapter 4 Exam 005

    •  The EtherChannel is suspended.
    •  The EtherChannel is not functional.
    •  The port aggregation protocol PAgP is misconfigured.
    •  FastEthernet ports Fa0/1, Fa0/2, and Fa0/3 do not join the EtherChannel.

    Explanation: The EtherChannel status shows as (SD), which means it is a Layer 2 EtherChannel with a status of D or down. Because the EtherChannel is down, the status of the interfaces in the channel group is stand-alone. PAgP is configured on S1, but there is no indication whether it is configured correctly on S1. The problem might also be the adjacent switch EtherChannel configuration.

15. Refer to the exhibit. Based on the command output shown, what is the status of the EtherChannel?

    

    CCNA3 v6.0 Chapter 4 Exam 002

    •  The EtherChannel is dynamic and is using ports Fa0/10 and Fa0/11 as passive ports.
    •  The EtherChannel is down as evidenced by the protocol field being empty.
    •  The EtherChannel is partially functional as indicated by the P flags for the FastEthernet ports.
    •  The EtherChannel is in use and functional as indicated by the SU and P flags in the command output.

    Explanation: The command output shows the port channel as SU, which means Layer 2 and in use; and the FastEthernet 0/10 and 0/11 interfaces are bundled in port-channel as indicated by the P flag. Configuring the EtherChannel using the channel-group 1 mode on command will cause the Protocol field in the command output to be empty.

16. What is a requirement to configure a trunking EtherChannel between two switches?
    •  The participating interfaces must be physically contiguous on a switch.
    •  The allowed range of VLANs must be the same on both switches.
    •  The participating interfaces must be on the same module on a switch.
    •  The participating interfaces must be assigned the same VLAN number on both switches.

    Explanation: To enable a trunking EtherChannel successfully, the range of VLANs allowed on all the interfaces must match; otherwise, the EtherChannel cannot be formed. The interfaces involved in an EtherChannel do not have to be physically contiguous, or on the same module. Because the EtherChannel is a trunking one, participating interfaces are configured as trunk mode, not access mode.

17. What is the purpose of HSRP?
    •  It provides a continuous network connection when a router fails.
    •  It prevents a rogue switch from becoming the STP root.
    •  It enables an access port to immediately transition to the forwarding state.
    •  It prevents malicious hosts from connecting to trunk ports.

    Explanation: HSRP is a first hop redundancy protocol and allows hosts to use multiple gateways through the use of a single virtual router.

18. Which nonproprietary protocol provides router redundancy for a group of routers which support IPv4 LANs?
    •  HSRP
    •  VRRPv2
    •  GLBP
    •  SLB

    Explanation: The only nonproprietary FHRP used for router redundancy listed in the options is VRRPv2. HSRP and GLBP are both Cisco proprietary FHRPs. IOS SLB is a Cisco-based solution used to load balance traffic across multiple servers.

19. Refer to the exhibit. A network administrator configured routers R1 and R2 as part of HSRP group 1. After the routers have been reloaded, a user on Host1 complained of lack of connectivity to the Internet The network administrator issued the show standby brief command on both routers to verify the HSRP operations. In addition, the administrator observed the ARP table on Host1. Which entry should be seen in the ARP table on Host1 in order to gain connectivity to the Internet?

    

    CCNA3 v6.0 Chapter 4 Exam 004

    •  the IP address and the MAC address of R1
    •  the virtual IP address and the virtual MAC address for the HSRP group 1
    •  the virtual IP address of the HSRP group 1 and the MAC address of R1
    •  the virtual IP address of the HSRP group 1 and the MAC address of R2

    Explanation: Hosts will send an ARP request to the default gateway which is the virtual IP address. ARP replies from the HSRP routers contain the virtual MAC address. The host ARP tables will contain a mapping of the virtual IP to the virtual MAC.

20. Refer to the exhibit. What statement is true about the output of the show standby command?

    

    CCNA3 v6.0 Chapter 4 Exam 003

    •  The current priority of this router is 120.
    •  The router is currently forwarding packets.
    •  This router is tracking two properly operating interfaces.
    •  This router is in the HSRP down state because its tracked interfaces are down.

    Explanation: The output shows that the active router is local and indicates that this router is the active router and is currently forwarding packets.

21. Refer to the exhibit. A network engineer is troubleshooting host connectivity on a LAN that uses a first hop redundancy protocol. Which IPv4 gateway address should be configured on the host?

    

    CCNA3 v6.0 Chapter 4 Exam 001

    •  192.168.2.0
    •  192.168.2.1
    •  192.168.2.2
    •  192.168.2.100

    Explanation: The host default gateway address should be the FHRP (in this case GLBP) virtual IP address.

22. A network administrator would like to ensure that router R1 is always elected the active router for an HSRP group. Which set of commands would ensure the required results?
    • R1(config-if)# ip address 192.168.1.100 255.255.255.0
      R1(config-if)# standby 1 ip 192.168.1.1
      R1(config-if)# standby 1 priority 1
      R1(config-if)# no shutdown
    • R1(config-if)# ip address 192.168.1.250 255.255.255.0
      R1(config-if)# standby 1 ip 192.168.1.1
      R1(config-if)# no shutdown
    • R1(config-if)# ip address 192.168.1.100 255.255.255.0
      R1(config-if)# standby 1 ip 192.168.1.1
      R1(config-if)# standby 1 priority 255
      R1(config-if)# standby 1 preempt
      R1(config-if)# no shutdown
    • R1(config-if)# ip address 192.168.1.100 255.255.255.0
      R1(config-if)# standby 1 ip 192.168.1.1
      R1(config-if)# standby 1 priority 150
      R1(config-if)# no shutdown

    Explanation: In order to configure HSRP, the standby command is used. The IP address given with the standby command is the virtual IP address used by hosts as a default gateway. A priority number of 255 is the highest that can be assigned and should be configured on the router that is to be the active router.

23. Fill in the blank.
    In FHRP operation, two or more routers are represented as a single       virtual    router.

24. Match the description to the correct command. (Not all options are used.)

    

    CCNA2 v6.0 Chapter 4 Exam 01

25. Open the PT Activity. Perform the tasks in the activity instructions and then answer the question.
    What are two reasons why the ping messages that are issued from Laptop0 towards Laptop1 are failing? (Choose two.)

    •  The channel group mode is not set correctly on the switches.
    •  The wrong cable types are connecting the two switches.
    •  The interface VLAN 1 is shut down on both switches.
    •  The channel group should be configured as a trunk on each switch.
    •  The two interfaces on each of the switches belong to different VLANs.

    Explanation: Port-channel 1 needs to be configured as a trunk in order to carry data about two different VLANs. The channel group is set as auto and desirable. The SVI has not been configured on the switches, but this does not affect the creation of an EtherChannel. The use of straight-through cables between switches is not an issue when using a Cisco Catalyst 2960 switch.

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1 New Updated May 2018

1.  In FHRP terminology, what represents a set of routers that present the illusion of a single router to hosts?

   • standby router
   • virtual router
   • forwarding router
   • default gateway