Scenarios

     

The following scenarios and questions are designed to draw together the content of the chapters and to exercise your understanding of the concepts. There is not necessarily a right answer. The thought process and practice in manipulating the concepts are the goals of this section. The answers to these scenarios immediately follow Scenario 19-3.

Scenario 19-1

The last network administrator of your company left abruptly. You were recently hired to the position and cannot find any documentation on the network. Using a network-management tool, you now have a topology map of the network.

Refer to Figure 19-1 and answer the questions that follow.

Figure 19-1. Diagram of Network for Scenario 19-1

1:	Offer some reasons why the routing protocol EIGRP has recently been implemented in the network, and give the reasons for its deployment in that particular area of the network.
2:	The ISP has decided that the company should set a default route into its domain. Write out the commands that would configure the default route.
3:	Is the router that is connecting to the ISP the only router that needs configuration? If this is the case, explain the reasons for your decision. If other routers need configuration, explain why they are needed and state where they would be applied.
4:	The ISP router connecting into the company network will need static routes configured. Write out the commands to configure the router.
5:	Will these routes need to be redistributed into the ISP domain? If the answer is yes, explain the reason for your decision, and then write out the configuration commands. If the answer is no, explain the reasons for your decision.
6:	Are filters required in this design? If so, state why, describe the type of filters required, and explain how and where they would be applied.
7:	A consultant has suggested that EIGRP should be configured using summarization. If this plan were to be implemented, on which routers would it be configured, and why?

Scenario 19-2

The company has recently merged with another company that has OSPF as its routing protocol. It has been determined that this is going to be the company standard. Figure 19-2 shows the topology for this scenario.

Figure 19-2. Diagram for Scenario 19-2

1:	Router A was chosen as the designated router on the LAN in the OSPF domain. Explain why this design choice was made, and give the command that would ensure its selection as the designated router.
2:	Redistribution is occurring between IGRP and OSPF on Router A; state the configuration commands that you would use for both IGRP and OSPF.
3:	The new headquarters of the merged company is in the OSPF domain. Therefore, because the connection to the Internet is also in this domain, it has been decided that Router A will have a default route configured to point to the OSPF domain from the IGRP domain. It will be necessary to configure the ip classless command for the IGRP domain. Explain why the ip classless command is needed and what it achieves.
4:	Explain the use of the subnet command in OSPF, and why it is required in redistribution.
5:	In a more complex topology with multiple redistribution points, explain why it might be necessary to filter when redistributing, and what it achieves in this network.

Scenario 19-3

Your company has decided to change its routing protocol from RIP to EIGRP. The company is currently running both IPX and IP. With reference to Figure 19-3, devise a design for the new network.

Figure 19-3. Diagram of Network for Scenario 19-3

Ensure that you include the following:

1:	Create a transition plan, showing how the final design will be implemented.
2:	If the transition plan requires redistribution, indicate these points on the diagram and provide the configuration commands.
3:	The company has also decided to connect to the Internet using EIGRP, upon which the ISP that is providing Internet connectivity has agreed. Is any redistribution required? Give reasons for your answers.
4:	Explain the neighbors that you see on the LAN segment and the path selection on Router B to network 140.100.0.0.
5:	Create a diagram that shows the final network design, with configuration commands for EIGRP on Router A.
6:	Write out the configuration commands for Router B.