OSPF Questions 2 Flashcards
Question 1
OSPF routing uses the concept of areas. What are the characteristics of OSPF areas? (Choose three)
A. Each OSPF area requires a loopback interface to be configured.
B. Areas may be assigned any number from 0 to 65535.
C. Area 0 is called the backbone area.
D. Hierarchical OSPF networks do not require multiple areas.
E. Multiple OSPF areas must connect to area 0.
F. Single area OSPF networks must be configured in area 1.
Answer: C D E
Explanation
C and E are correct according to the theory of OSPF. For answer E, it is a bit unclear but we can understand “Hierarchical OSPF networks do not require multiple areas” is correct because there are networks that are small enough to use only area 0 for the whole network.
Question 2
Open Shortest Path First (OSPF) is a dynamic routing protocol for use in Internet Protocol (IP) networks.
If configuring all OSPF routers in a single area with the same priority value, what value does a router use for the OSPF router ID in the absence of a loopback interface?
A. the IP address of the first Fast Ethernet interface
B. the IP address of the console management interface
C. the highest IP address among its active interfaces
D. the lowest IP address among its active interfaces
E. the priority value until a loopback interface is configured
Answer: C
Question 3
OSPF_Routing.jpg
R1 routing commands:
ip route 0.0.0.0 0.0.0.0 serial0/0
router ospf 1
network 172.16.100.0 0.0.0.3 area 0
network 172.16.100.64 0.0.0.63 area 0
network 172.16.100.128 0.0.0.31 area 0
default-information originate
Assuming that all router interfaces are operational and correctly configured, that OSPF has been correctly configured on router R2, how will the default route configured on R1 affect the operation of R2?
A. Any packet destined for a network that is not directly connected to router R1 will be dropped.
B. Any packet destined for a network that is not referenced in the routing table of router R2 will be directed to R1. R1 will then send that packet back to R2 and a routing loop will occur.
C. Any packet destined for a network that is not directly connected to router R2 will be dropped immediately.
D. Any packet destined for a network that is not directly connected to router R2 will be dropped immediately because of the lack of a gateway on R1.
Answer: B
Explanation
Please read the explanation of this question at http://www.9tut.com/ccna-ospf-questions (question 6)
Question 4
Border# debug ip ospf events
OSPF events debugging is on
Border#
*Nov 4 03:49:37477: OSPF: Rev hello from 10.10.3.3 area 0 from Serial0/3 192.168.255.18
*Nov 4 03:49:37.481: OSPF: End of hello processing
*Nov 4 03:49:37.641: OSPF: Rev hello from 10.10.1.1 area 0 from Serial0/1 192.168.255.22
“Nov 4 03:49:37.645: OSPF: Mismatched hello parameters from 192.168.255.22
*Nov 4 03:49:37.645: OSPF: Dead R 40 C 56, Hello R 10 C 14
What conclusion can be drawn from the output of the debug command presented in the exhibit?
A. The output represents normal OSPF operation.
B. A router is connected to interface Serial0/3 of the Border router.
The OSPF router ID of the connected router is the IP address of the connected interface.
C. The interfaces of two OSPF routers connected to the Border router are in the same subnet.
D. The OSPF router connected to interface Serial0/1 has NOT formed a neighbor relationship with the Border router.
Answer: D
Explanation
From the debug line “Mismatched hello parameters from 192.168.255.22″ we learn that there is a mismatched parameter in the hello packet (Hello interval, Dead interval or AREA number).
Question 5
Which characteristics are representative of a link-state routing protocol? (Choose three)
A. provides common view of entire topology
B. exchanges routing tables with neighbors
C. calculates shortest path
D. utilizes event-triggered updates
E. utilizes frequent periodic updates
Answer: A C D
Question 6
When running OSPF, what would cause router A not to form an adjacency with router B?
A. The loopback addresses are on different subnets.
B. The values of the dead timers on the routers are different.
C. Route summarization is enabled on both routers.
D. The process identifier on router A is different than the process identifier on router
Answer: B
Question 7
What is the OSPF router ID in a DR/BDR election used for?
A. It is used with the OSPF priority values to determine which interface will be used to form a neighbor relationship with another OSPF router.
B. It is used with the OSPF priority values to determine which OSPF router will become the DR or BDR in a point-to-point network.
C. It is used with the OSPF priority values to determine which router will become the DR or BDR in a multiaccess network.
D. It is used to determine which interfaces will send Hello packets to neighboring OSPF routers.
Answer: C
Question 8
A network associate has configured OSPF with the command:
City(config-router)# network 192.168.12.64 0.0.0.63 area 0
After completing the configuration, the associate discovers that not all the interfaces are participating in OSPF.
Which three of the interfaces shown in the exhibit will participate in OSPF according to this configuration statement? (Choose three)
A. FastEthernet0/0
B. FastEthernet0/1
C. Serial0/0
D. Serial0/1.102
E. Serial0/1.103
F. Serial0/1.104
Answer: B C D
Explanation
The “network 192.168.12.64 0.0.0.63″ equals to network 192.168.12.64/26. This network has:
+ Increment: 64 (/26= 1111 1111.1111 1111.1111 1111.1100 0000)
+ Network address: 192.168.12.64
+ Broadcast address: 192.168.12.127
Therefore all interface in the range of this network will join OSPF -> B C D are correct.
Question 9
To maintain connectivity with neighboring routers, routers running OSPF will send some type of packets. What is the type of packets?
A. OSP packets
B. hello packets
C. LSU packets
D. dead interval packets
Answer: B
Question 10
A network administrator is configuring the routers in the graphic for OSPF.
The OSPF process has been started and the networks have been configured for Area 0 as shown in the diagram.
The network administrator has several options for configuring RouterB to ensure that it will be preferred as the designated router (DR) for the 172.16.1.0/24 LAN segment.
What configuration tasks could be used to establish this preference? (Choose three)
A. Change the priority value of the Fa0/0 interface of RouterB to zero.
B. Configure the priority value of the Fa0/0 interface of RouterB to a higher value than any other interface on the Ethernet network.
C. Change the priority values of the Fa0/0 interfaces of RouterA and RouterC to zero.
D. Configure a loop back interface on RouterB with an IP address higher than any IP address on the other routers.
E. No further configuration is necessary.
Answer: B C D
Question 11
Open Shortest Path First (OSPF) is a dynamic routing protocol for use in Internet Protocol (IP) networks, while EIGRP is short for Enhanced Interior Gateway Routing Protocol. A large corporate which often integrates networks from newly acquired businesses has just decided to use OSPF to replace EIGRP as the corporate routing protocol.
Which two benefits will the corporation obtain by changing from EIGRP to OSPF? (Choose two)
A. the ability to automatically summarize networks
B. the ability to create a hierarchical design using areas
C. the ability to support multi-vendor routers
D. the ability to redistribute default and static routes
E. the ability to use VLSM
Answer: B C
Question 12
What are three characteristics of the OSPF routing protocol? (Choose three)
A. It converges quickly
B. OSPF is a classful routing protocol
C. It uses cost to determine the best route
D. It uses the DUAL algorithm to determine the best route
E. OSPF routers send the complete routing table to all directly attached routers
F. OSPF routers discover neighbors before exchanging routing information
Answer: A C F
