Do You Shoot Trouble or Does Trouble Shoot You?
Troubleshooting is all about reducing guesswork and eliminating the obvious. Following a systematic method is essential during the troubleshooting process. Methodical problem solving is the core of the CIT course, the CCNP Troubleshooting test, and this book, regardless of technical intricacies. Many times, whether or not you use a systematic method determines if you shoot trouble or if trouble shoots you.
Shooting trouble is often about questions. Do you ask the equipment or the user? Who is waiting for the results? What has happened? When did it occur? Why? Where did it happen? Are you using 10/100-Mbps Ethernet to the desktop; 155-Mbps ATM; or carrier services such as cable modems, digital subscriber line (DSL), wireless, ISDN, Frame Relay, Switched Multimegabit Data Service (SMDS), ATM, or long-haul Ethernet? The protocols, technologies, media, and topologies entail lots of complexity and the only thing constant is change. So where do you begin?
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Appendix A material from the Cisco instructor-led Cisco Internetwork Troubleshooting (CIT) course for the CCNP Support exam is covered throughout this chapter and in more detail in the relevant chapters of this book. Consider this chapter fertile with test material; even more importantly, it makes an excellent practical review.
The first topic is standards and protocols. Think back for a moment to the last time you chatted with a friend. Certainly you and your friend had something to share, regardless of the method used to communicate. If you made a phone call, you were listening to each other talk. If you sent an e-mail or used a chat client, you were sending data back and forth. Whether it was your home phone, wireless phone, or PC, communications media was in place nonetheless. I assume that you waited for the friend to say hello first and that you took turns talking. You spoke the same language or understood multiple languages. Hopefully, you were polite enough to not talk while the other person was talking. You may have had to troubleshoot some issues while talking with the friend. Perhaps a lightning storm hit your phone line or you dialed the wrong number. Maybe you didn't pay your phone bill and the service was turned off. The friend may not have answered or the phone may have been busy. Maybe your friend had caller ID and picked up right away because it was you. Regardless of your exact scenario, throughout the contact you had to decide your next step.
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Continue to think about your communications with your friend as you read through this chapter. You may begin to see how a different perspective or an analogy can help you to simplify complex topics. Throughout this book, I include occasional analogies I have found to be very helpful to my students learning in the classroom.