Cisco CCNA mock exam questions sample test – Question 4

Your assistant just finished configuring a small test network as part of his training. The network is configured as shown in the diagram below:
CCNA Q 4

When testing the configuration, you find that Host A in the diagram cannot ping Host B.
Which of the following pairs of connections are required to be in the same subnet for Host A to be able to ping Host B? (Choose all that apply.)
A. The IP address of Host A and the IP address of the Fa0/0 interface of Router A
B. The IP address of the Fa0/0 interface of Router A and the IP address of the Fa0/0 interface of Router B
C. The IP address of Host A and the IP address of the Fa0/0 interface of Router B
D. The IP address of Host A and the IP address of Switch A
E. The IP address of the S 0/0 interface of Router A and the IP address of the S 0/0 interface of Router B
F. The IP address of Host A and the IP address of Host B
G. The IP address of Host B and the IP address of the Fa0/0 interface of Router B

Correct Answers: A,E,G

Explanation:
The following pairs of connections are required to be in the same subnet:
the IP address of Host A and the IP address of the Fa0/0 interface of Router A
the IP address of the S 0/0 interface of Router A and the IP address of the S 0/0 interface of Router B
the IP address of Host B and the IP address of the Fa0/0 interface of Router B
When troubleshooting a correctly labeled network diagram for IP addressing problems, one must start on one end and trace each link in one direction, ensuring at each step that the interfaces are in the same subnet. A switch simply passes the packet to the router; therefore, the IP address of the switch is not important. It performs its job even if it has no IP address.
Moving from Host A to Host B, however, the following links must be in the same subnet:
The IP address of Host A and the IP address of the Fa0/0 interface of Router A
The IP address of the S0/0 interface of Router A and the IP address of the S0/0 interface of Router B
The IP address of Host B and the IP address of the Fa0/0 interface of Router B
Neither of the switch addresses is important to the process.
If all other routing issues are correct, it is also not required for Host A and Host B to be in the same subnet.

Objective:
Network Fundamentals

Sub-Objective:
Configure, verify, and troubleshoot IPv4 addressing and subnetting

References:
Cisco > Home > Support > Technology Support > IP > IP Routing > Design > Design Technotes > IP Addressing and Subnetting for New Users