CCNA – OSPF Questions

Note: If you are not sure about OSPF, please read our OSPF Tutorial.

Question 1

Question 2

Explanation

Answer A and C are obviously correct. For answer E, it allows extensive control of routing updates via Link-State Advertisement (LSA). Administrators can filter these LSAs to meet their requirements easily.

Question 3

Question 4

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 5

Explanation

The default number of equal-cost paths that can be placed into the routing of a Cisco OSPF router is 4. We can change this default value by using “maximum-paths” command:

Router(config-router)#maximum-paths 2

Note: Cisco routers support up to 6 equal-cost paths

Question 6

Question 7

Explanation

Hierarchical design of OSPF (basically means that you can separate the larger internetwork into smaller internetworks called areas) helps us create a network with all features listed above (decrease routing overhead, speed up convergence, confine network instability to single areas of the network).

Question 8

Explanation

In the router ospf command, the ranges from 1 to 65535 so o is an invalid number -> A is correct but B is not correct.

Question 9

Explanation

The highest IP address of all loopback interfaces will be chosen -> Loopback 0 will be chosen as the router ID.

Question 10