New CCNA OSPF Lab Sim

By | October 28, 2017

This is an Updated real CCNA exam question (August 2017). You might see a different IP addressing, VLAN configuration and Port allocation and OSPF Configurations.

As usual, take time to read through the question so as to clearly understand what Cisco wants you to do.

Note: This OSPF LAB are used for demonstration purposes only, you might see different IP addressing,  configuration and Port allocation in the real CCNA exam. But it all works the same way, try and understand the technique.

I suggest you use packet tracer for practice.

Download Cisco Packet tracer

 




Use the exhibit below to answer the question that follows.

Question

Scenario
Refer to the topology. Company XYZ has decided to connect the main office with three other remote branch offices using point-to-point serial links.
You as the network administrator is required to troubleshoot and resolve OSPF neighbor adjacency issues between the main office and the routers located in the remote branch offices.

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 : D

Explanation:

To answer such question, you are required to use the show running-config command on router 3 and router 6 to view configuration setting:

Study the following output:

 

 

  Looking at the output above from both routers, we can verify that R6 has been incorrectly configured with the same router ID as R3. This will cause both routers not to form an OSPF neighbor adjacency.

Question 

Scenario:
Refer to the topology.  Company XYZ has decided to connect the main office with three other remote branch offices using point-to-point serial links. You as the network administrator is required to troubleshoot and resolve OSPF neighbor adjacency issues between the main office and the routers located in the remote branch offices.

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

A. R1 ethernet0/1 is shutdown. Configure no shutdown command.
B. R1 ethernet0/1 configured with a non-default OSPF hello interval of 25; configure no ip ospf hello-interval 25.
C. R2 ethernet0/1 and R3 ethernet0/0 are configured with a non-default OSPF hello interval of 25; configure no ip ospf hello-interval 25.
D. Enable OSPF for R1 ethernet0/1; configure ip ospf 1 area 0 command under ethernet0/1.

Answer: B

Explanation:

Here also, you are required to use the show running-config command:

Study the output:

Looking at the output of both routers configuration, you will notice that R1 is configured with a hello interval of 25 on interface Ethernet 0/1 while R2 is left with the default of 10 (not configured). This will also cause both routers not to form OSPF neighbor adjacency.