CCNA Exam Questions and Answers - OSPF SIM

OSPF - SIM

Question - 1    An OSPF neighbor adjacency is not formed between R3 in the main office and R4 in the Branch-1 office. What is causing the problem?

                          A. There is an area ID mismatch.
                          B. There is a Layer 2 issue; an encapsulation mismatch on serial links.
                          C. There is an OSPF hello and dead interval mismatch.
                          D. The R3 router ID is configured on R4.

Answer is A

Explanation - We know it is OSPF problem and we should check the interface configuration on both routers (S1/0 of both R3 and R4 routers). When we check we will come to know that OSPF area ID is configured differently on both routers .

Question - 2     An OSPF neighbor adjacency is not formed between R3 in the main office and R5 in the Branch2 office. What is causing the problem?

                          A. There is an area ID mismatch.
                          B. There is a PPP authentication issue; a password mismatch.
                          C. There is an OSPF hello and dead interval mismatch.
                          D. There is a missing network command in the OSPF process on R5.

Answer is C

Explanation - We have to check interface configuration between R3 and R5 (Interface S1/0 on both routers) and we will know that Hello and Dead interval in configured differently. We can also check this by using #sh ip ospf interface <interafce> command.

Question - 3     R1 does not form an OSPF neighbor adjacency with R2. Which option would fix the issue?

                         A. R1 ethernetO/1 is shutdown. Configure no shutdown command.
                         B. R1 ethernetO/1 configured with a non-default OSPF hello interval of 25:                                                configure no ip ospf hello-interval 25
                         C. R2 ethernetO/1 and R3 ethernetO/O are configured with a non-default OSPF hello                                interval of 25; configure no ip ospf hello-interval 25
                         D. Enable OSPF for R1 ethernetO/1; configure ip ospf 1 area 0 command under                                         ethernetO/1

Answer is C

Explanation - When we check the interface configuration between two routers we can see that OSPF hello interval (25) is configured on R1.

Question - 4      An OSPF neighbor adjacency is not formed between R3 in the main office and R6 in the Branch3 office. What is causing the problem?

                       A. There is an area ID mismatch.
                       B. There is a PPP authentication issue; the username is not configured on R3 and R6.
                       C. There is an OSPF hello and dead interval mismatch.
                       D. The R3 router ID is configured on R6.

Answer is D

Explanation - When we check the OSPF configuration on both routers we can see that same router ID is configured on both routers.