CÂU HỎI THI THẬT VỀ OSPF

Question #403 Topic 1

A network administrator is troubleshooting the OSPF configuration of routers R1 and R2. The routers cannot establish an adjacency relationship on their common
Ethernet link.

The graphic shows the output of the show ip ospf interface e0 command for routers R1 and R2. Based on the information in the graphic, what is the cause of this problem?

• A. The OSPF area is not configured properly.
• B. The priority on R1 should be set higher.
• C. The cost on R1 should be set higher.
• D. The hello and dead timers are not configured properly.
• E. A backup designated router needs to be added to the network.
• F. The OSPF process ID numbers must match.

Correct Answer: D

Question #1074 Topic 1

Refer to the exhibit. A network engineer is verifying the settings on a new OSPF network. All OSPF configurations use the default values unless otherwise indicated. Which router does the engineer expect will be elected as the DR when all devices boot up simultaneously?

• A. R1
• B. R2
• C. R3
• D. R4

Correct Answer: D 

Question #1198 Topic 1

Refer to the exhibit. Router R1 receives static routing updates from routers A, B, C, and D. The network engineer wants R1 to advertise static routes in OSPF area 1. Which summary address must be advertised in OSPF?

• A. 10.1.41.0/25
• B. 10.1.40.0/24
• C. 10.1.40.0/25
• D. 10.1.40.0/23

Correct Answer: D 

Question #1318 Topic 1

Refer to the exhibit. The network engineer is confining router R2 as a replacement router on the network. After the initial configuration is applied, it is determined that R2 failed to show R1 as a neighbor. Which configuration must be applied to R2 to complete the OSPF configuration and enable it to establish the neighbor relationship with R1?

• A. R2(config)#interface g0/0/0 -
  R2(config-if)#ip ospf hello-interval 10
• B. R2(config)#router ospf 1 -
  R2(config-router)#router-id 192.168.1.1
• C. R2(config)#router ospf 1 -
  R2(config-router)#network 192.168.1.0 255.255.255.0 area 2
• D. R2(config)#interface g0/0/0 -
  R2(config-if)#ip ospf dead-interval 45

Correct Answer: A 🗳️

Question #353 Topic 1

Which two minimum parameters must be configured on an active interface to enable OSPFV2 to operate? (Choose two.)

• A. OSPF process ID
• B. OSPF MD5 authentication key
• C. OSPF stub flag
• D. IPv6 address
• E. OSPF area

Correct Answer: AE 🗳️

Question #355 Topic 1

Refer to the exhibit. What does router R1 use as its OSPF router-ID?

• A. 10.10.1.10
• B. 10.10.10.20
• C. 172.16.15.10
• D. 192.168.0.1

Correct Answer: C 🗳️
OSPF uses the following criteria to select the router ID:
1. Manual configuration of the router ID (via the ג€router-id x.x.x.xג€ command under OSPF router configuration mode).
2. Highest IP address on a loopback interface.
3. Highest IP address on a non-loopback and active (no shutdown) interface.

Question #365 Topic 1

Router A learns the same route from two different neighbors; one of the neighbor routers is an OSPF neighbor, and the other is an EIGRP neighbor.
What is the administrative distance of the route that will be installed in the routing table?

• A. 20
• B. 90
• C. 110
• D. 115

Correct Answer: B 🗳️
The Administrative distance (AD) of EIGRP is 90 while the AD of OSPF is 110 so EIGRP route will be chosen to install into the routing table.

Question #368 Topic 1

Refer to the exhibit. If OSPF is running on this network, how does Router2 handle traffic from Site B to 10.10.13.128/25 at Site A?

• A. It sends packets out of interface Fa0/1 only.
• B. It sends packets out of interface Fa0/2 only.
• C. It load-balances traffic out of Fa0/1 and Fa0/2.
• D. It cannot send packets to 10.10.13.128/25.

Correct Answer: D 🗳️
Router2 does not have an entry for the subnet 10.10.13.128/25. It only has an entry for 10.10.13.0/25, which ranges from 10.10.13.0 to 10.10.13.127.

Question #377 Topic 1

You have configured a router with an OSPF router ID, but its IP address still reflects the physical interface.
Which action can you take to correct the problem in the least disruptive way?

• A. Reload the OSPF process
• B. Specify a loopback address
• C. Reboot the router
• D. Save the router configuration

Correct Answer: A 🗳️
Once an OSPF Router ID selection is done, it remains there even if you remove it or configure another OSPF Router ID. So the least disruptive way is to correct it using the command clear ip ospf process

Question #384 Topic 1

Which two circumstances can prevent two routers from establishing an OSPF neighbor adjacency? (Choose two.)

• A. mismatched autonomous system numbers
• B. an ACL blocking traffic from multicast address 224.0.0.10
• C. mismatched process IDs
• D. mismatched hello timers and dead timers
• E. use of the same router ID on both devices

Correct Answer: DE 🗳️

Question #427 Topic 1

Refer to the graphic. R1 is unable to establish an OSPF neighbor relationship with R3. What are possible reasons for this problem? (Choose two.)

• A. All of the routers need to be configured for backbone Area 1.
• B. R1 and R2 are the DR and BDR, so OSPF will not establish neighbor adjacency with R3.
• C. A static route has been configured from R1 to R3 and prevents the neighbor adjacency from being established.
• D. The hello and dead interval timers are not set to the same values on R1 and R3.
• E. EIGRP is also configured on these routers with a lower administrative distance.
• F. R1 and R3 are configured in different areas.

Correct Answer: DF 🗳️
This question is to examine the conditions for OSPF to create neighborhood. So as to make the two routers become neighbors, each router must be matched with the following items:
1. The area ID and its types
2. Hello and failure time interval timer
3. OSPF Password (Optional)