Scenario Answers

     

The answers provided in this section are not necessarily the only possible answers to the questions. The questions are designed to test your knowledge and to give practical exercise in certain key areas. This section is intended to test and to exercise skills and concepts detailed in the body of this chapter.

If your answer is different, ask yourself whether it follows the tenets explained in the answers provided. Your answer is correct not if it matches the solution provided in the book, but rather if it has included the principles of design laid out in the chapter.

In this way, the testing provided in these scenarios is deeper: It examines not only your knowledge, but also your understanding and ability to apply that knowledge to problems.

If you do not get the correct answer, refer back to the text and review the subject tested . Be certain also to review your notes on the question to ensure that you understand the principles of the subject.

Scenario 17-1 Answers

1:	Issue the configuration commands for the RIP network to be redistributed on Router A into EIGRP.
A1:	The commands are as follows: Router(config)# router eigrp 300 Router(config-router)# network 210.77.8.0 Router(config-router)# redistribute rip Router(config-router)# default-metric 10000 100 255 1 1500
2:	On Router A, ensure that the interfaces running EIGRP do not have RIP updates generated through them or that the RIP interfaces do not have EIGRP updates running through them.
A2:	Strictly speaking, the passive-interface command on s0.2 is not required because the interface address is different from that stated in the network command. The same is true for RIP. To ensure this: Router(config#r outer eigrp 300 Router(config-router)# network 210.77.8.0 Router(config-router)# redistribute rip Router(config-router)# default-metric 10000 100 255 1 1500 Router(config-router)# passive-interface s0.2 Router(config)# router rip Router(config-router)# network 201.77.10.0 Router(config-router)# passive-interface s0.1 Router(config-router)# passive-interface s0.3 Router(config-router)# passive-interface e0 Router(config-router)# passive-interface e1
3:	The site running IGRP and the site running EIGRP are running different autonomous system numbers . How would you implement a transition to both sites running EIGRP using the same autonomous system number?
A3:	There are several ways to transition from different autonomous systems to one autonomous system so that IGRP and EIGRP automatically redistribute. The methods include the following: - Configuring redistribution at both sites, and in a controlled manner during downtime, switching all the routers in the IGRP site to the same autonomous system as that of EIGRP. Because the prevailing routing protocol is to be EIGRP, it makes sense that IGRP is the protocol to have its autonomous system number changed. - Another approach, and one favored by many, is to configure EIGRP with the same autonomous system number on all routers at the IGRP site. As part of the configuration, increase the administrative distance of EIGRP to be 200 so that none of the routes is acceptable to the routing process. Then, during downtime on the systems, cut over to the EIGRP process by changing its administrative distance back to the default of 90. This can be done by simply adding the word no in front of the existing command. The beauty of this plan is that everything can be put in place before the cutover; if problems are experienced , it is equally easy to reverse the command to return to the IGRP configuration.
4:	The OSPF redistribution into RIP has been implemented, but users are complaining about delays. State the first step that you would take to verify the configuration.
A4:	The first step is to issue the following commands, perhaps on both the OSPF and RIP routers: - show ip route : To ensure that each routing process sees the appropriate paths. A routing loop might be visible here. - extended ping : To see the path that is taken to the remote locations. A routing loop could be detected . - show ip protocols : To see how RIP and OSPF are being redistributed, what the default metrics are, and whether there are any distribute lists impeding the flow of updates. - show ip ospf database : To ensure that all the routes are in place. Again, errors leading to a routing loop could be detected here. - show ip ospf neighbor : To ensure that OSPF can still see the adjacent routers.
5:	The CIO has been asked to submit a transition plan to the board of trustees that includes a reasoned explanation for the need for redistribution. What should it look like?
A5:	It should include the following: - The transition would happen at the main site where the centralized records and databases are maintained . This is because this site must be the most stable because it serves the other sites. - The next step would be to review the addressing scheme to ensure that it was hierarchical and could support summarization and VLSM. - The redistribution between IGRP and EIGRP is the easiest to effect and should be performed in accordance to the answer in question 3. - Because the non-Cisco Systems equipment for RIP and OSPF machines might not support EIGRP, a careful assessment should be done, and plans should be made to upgrade the equipment as necessary. However, the network administrator should be reminded that it is not necessary for hosts to run RIP. If hosts run RIP, it can lead to a very unstable network. Therefore, all hosts should be configured with a default gateway address. - Configure redistribution in the network to ensure the full connectivity throughout the campuses. - When redistribution is in place, centralization of resources and maintenance of the data and network can be implemented, granting a full exchange of information throughout the hospital to harness the power of the information available.

1:	Issue the configuration commands for the RIP network to be redistributed on Router A into EIGRP .
2:	On Router A, ensure that the interfaces running EIGRP do not have RIP updates generated through them or that the RIP interfaces do not have EIGRP updates running through them.
3:	The site running IGRP and the site running EIGRP are running different autonomous system numbers. How would you implement a transition to both sites running EIGRP using the same autonomous system number?
4:	The OSPF redistribution into RIP has been implemented, but users are complaining about delays. State the first step that you would take to verify the configuration.
5:	The CIO has been asked to submit a transition plan to the board of trustees that includes a reasoned explanation for the need for redistribution. What should it look like?