CCNA 3 Chapter 8 V6.0 Answers

1. What happens immediately after two OSPF routers have exchanged hello packets and have formed a neighbor adjacency?

They exchange DBD packets in order to advertise parameters such as hello and dead intervals.

They negotiate the election process if they are on a multiaccess network.

They request more information about their databases.

They exchange abbreviated lists of their LSDBs.


2. What is used to create the OSPF neighbor table?

link-state database

adjacency database

routing table

forwarding database


3. What does a Cisco router use automatically to create link-local addresses on serial interfaces when OSPFv3 is implemented?

an Ethernet interface MAC address available on the router, the FE80::/10 prefix, and the EUI-64 process

the FE80::/10 prefix and the EUI-48 process

the MAC address of the serial interface, the FE80::/10 prefix, and the EUI-64 process

the highest MAC address available on the router, the FE80::/10 prefix, and the EUI-48 process


4. Which command will verify that a router that is running OSPFv3 has formed an adjacency with other routers in its OSPF area?

Show ipv6 route ospf

show running-configuration

show ipv6 interface brief

show ipv6 ospf neighbor


5. Match the information to the command that is used to obtain the information. (Not all options are used.)

Match the information to the command that is used to obtain the information

show ip ospf neighbor = Neighbor ID of

show ip ospf = Routing Process “ospf 10” with ID

show ip protocols = Routing Protocol is "ospf 10"

show interface serial 0/0/0 = BW 1544 Kbit/sec


6. Which three addresses could be used as the destination address for OSPFv3 messages? (Choose three.)








7. Which OPSF packet contains the different types of link-state advertisements?







8. Match the OSPF state with the order in which it occurs. (Not all options are used.)

Match the OSPF state with the order in which it occurs

Place the options in the following order:

second state -> Init state

seventh state -> Full state

fifth state -> Exchange state

first state -> Down state

fourth state -> Exstart state

third state -> Two-way state

sixth state -> Loading state


9. Match each OSPF packet type to how it is used by a router. (Not all options are used.)

Match each OSPF packet type to how it is used by a router

establish and maintain adjacencies = hello packet

advertise new information = link-state update packet

compare local topology to that sent by another router = database description packet

query another router for additional information = link-state request packet


10. By default, what is the OSPF cost for any link with a bandwidth of 100 Mb/s or greater?






11. Fill in the blank.The election of a DR and a BDR takes place on _multiaccess_ networks, such as Ethernet networks.


12. By order of precedence, match the selection of router ID for an OSPF-enable router to the possible router ID options. (Not all option are used.)

match the selection of router ID for an OSPF-enable router to the possible router ID options

loopback interface address = Third precedence

Serial interface IP address = Fourth precedence

Configured router ID = First precedence

Loopback interface IP address = Second precedence


13. Which command should be used to check the OSPF process ID, the router ID, networks the router is advertising, the neighbors the router is receiving updates from, and the default administrative distance?

show ip ospf neighbor

show ip ospf interface

show ip protocols

show ip ospf


14. What are two reasons that will prevent two routers from forming an OSPFv2 adjacency? (Choose two.)

mismatched subnet masks on the link interfaces

use of private IP addresses on the link interfaces

mismatched OSPF Hello or Dead timers

one router connecting to a FastEthernet port on the switch and the other connecting to a GigabitEthernet port

a mismatched Cisco IOS version that is used


15. Which command will provide information specific to OSPFv3 routes in the routing table?

show ipv6 route

show ipv6 route ospf

show ip route ospf

show ip route


16. Single area OSPFv3 has been enabled on a router via the ipv6 router ospf 20 command. Which command will enable this OSPFv3 process on an interface of that router?

ipv6 ospf 20 area 20

ipv6 ospf 20 area 0

ipv6 ospf 0 area 0

ipv6 ospf 0 area 20


17. Open the PT Activity. Perform the tasks in the activity instructions and then answer the question. R1 and R2 could not establish an EIGRP adjacency. What is the problem?

EIGRP is down on R1.

EIGRP is down on R2.

R1 Fa0/0 and R2 Fa0/0 are on different networks.

R1 Fa0/0 is not configured to send hello packets.

R1 Fa0/0 link local address is wrong.


18. When a network engineer is configuring OSPFv3 on a router, which command would the engineer issue immediately before configuring the router ID?

clear ipv6 ospf process

interface serial 0/0/1

ipv6 router ospf 10

ipv6 ospf 10 area 0


19. Fill in the blank.

OSPF uses _cost_ as a metric.


20. What are the two purposes of an OSPF router ID? (Choose two.)

to uniquely identify the router within the OSPF domain

to facilitate the transition of the OSPF neighbor state to Full

to facilitate the establishment of network convergence

to enable the SPF algorithm to determine the lowest cost path to remote networks

to facilitate router participation in the election of the designated router


21. Which OSPF component is identical in all routers in an OSPF area after convergence?

SPF tree

adjacency database

link-state database

routing table


22. What will an OSPF router prefer to use first as a router ID?

the highest active interface IP that is configured on the router

any IP address that is configured using the router-id command

the highest active interface that participates in the routing process because of a specifically configured network statement

a loopback interface that is configured with the highest IP address on the router


23. A network administrator enters the command ipv6 router ospf 64 in global configuration mode. What is the result of this command?

The reference bandwidth will be set to 64 Mb/s.

The router will be assigned an autonomous system number of 64.

The OSPFv3 process will be assigned an ID of 64.

The router will be assigned a router ID of 64.

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