Chapter 17. Troubleshooting

   

In this chapter you will have the opportunity to troubleshoot different internetworking problems. The chapter presents four scenarios in which you identify the problem, isolate where the issue resides, and then resolve the problem.

Before beginning with the scenarios, you should familiarize yourself with a few basic troubleshooting steps. One of the most important items to remember about troubleshooting is to have a process or a methodology that you can repeat for every internetworking problem that you might encounter. From our own experiences and studies, we recommend using the OSI reference model to isolate these problems. That is, always start at the physical layer, verify that no problems exist, and then move on to the data link layer, on to the network layer, and so on. This provides a repeatable process to all internetworking problems.

Another helpful hint is to always start the troubleshooting process closest to where the symptom is experienced . For instance, if users on router R6 are having problems accessing a resource off router R1, start the troubleshooting process on R6 and then move on to the next router in the path to the destination router, R1. This will follow the path of the symptom until the source of the problem is isolated and can be resolved. These processes are demonstrated in the scenarios included in this chapter.

To troubleshoot properly, you will need to understand the physical topology, the logical addressing, and routing domain boundaries. This chapter refers to the complete lab diagram, shown in Figure 17-1, that you should have been developing throughout the book.

Figure 17-1. Completed Lab Diagram

graphics/17fig01.gif


   
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CCNA Practical Studies
CCNA Practical Studies (Cisco Certification & Training)
ISBN: 1587200465
EAN: 2147483647
Year: 2005
Pages: 127

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