If Cisco TAC request these logs, you can access them by going to MANAGEMENT > Tech Support > Controller Crash.. Using the Cisco Spectrum Expert Cisco Spectrum Expert addresses the proble
Trang 1Using Tech Support
You might also find the Tech Support Pages, found at MANAGEMENT > Tech Support,
to be of benefit Although Cisco TAC uses most of what you do here, you might find it beneficial information for troubleshooting
Crash logs, which the controller maintains, are created when a system fails You cannot use most of the information found in the logs without Cisco TAC assistance If Cisco TAC
request these logs, you can access them by going to MANAGEMENT > Tech Support > Controller Crash Five crash dump files can be stored on a controller at any given time APs also create a crash log file that the controller can download Go to MANAGEMENT
> Tech Support >AP Crash Log > Get Log to retrieve it TAC also uses the AP crash logs Figure 20-5 SNMP Trap Logs
Trang 2Using WCS Version 5.x to Troubleshoot Clients You can use WCS to troubleshoot wireless deployments Use the Monitor > Client page
to troubleshoot clients You can see this page in Figure 20-6 When you use this tool, you get a Summary page with a list of problems and corresponding solutions The page also has a log analysis and a detailed event history
You can use the alarms to troubleshoot In the Clients Summary page, click the numerous alarms in the lower left to be taken to that Alarm page Figure 20-6 shows several critical alarms
Using the Cisco Spectrum Expert
Cisco Spectrum Expert addresses the problem of RF interference in wireless networks
With Cisco Spectrum Expert, you can detect, classify, locate, and manually mitigate sources of wireless interference
The Cisco Spectrum Expert Wi-Fi is the industry-leading spectrum intelligence product for Wi-Fi networks Cisco Spectrum Expert Wi-Fi offers complete visibility into the RF physical layer in the 2.4-GHz and 5-GHz frequencies, allowing for enhanced performance, security, and reliability of WLAN services
Figure 20-6 Critical Alarms
Trang 3The Cisco Spectrum Expert Wi-Fi includes the following components:
■ Cisco Spectrum Expert Wi-Fi sensor
■ Cisco Spectrum Expert software
■ Cisco Spectrum Expert antenna The Cisco Spectrum Expert Wi-Fi sensor is a sensor in the CardBus card form factor for notebooks It is supported on Microsoft Windows–based laptops and delivers compre-hensive spectrum intelligence Network administrators can streamline wireless network troubleshooting with better visibility into the RF spectrum and can easily identify and de-tect sources of wireless interference
Cisco Spectrum Expert provides a comprehensive list of all access points, ad hoc net-works, and interferer devices (for example, microwave ovens, cordless phones, wireless se-curity cameras, Bluetooth devices, and RF jammers)
Cisco Spectrum Expert also gives you a Channel Summary that provides visibility of RF activity—such as power levels and presence of 802.11 and interferer devices—on a channel-by-channel basis
The Devices View provides a deeper look at each device and its impact to the wireless net-work, including power level, channel coverage, and other data
A Device Finder tracks down the location of devices, causing wireless interference throughout your enterprise The Device Classifier offers the most comprehensive classifi-cation of the RF devices, which include the following:
■ Wi-Fi access points
■ In-network devices
■ Known devices
■ Unknown devices
■ Ad hoc devices
■ Wi-Fi stations
■ A variety of Bluetooth devices
■ A variety of cordless phones1
■ Microwave ovens
■ Generic fixed-frequency devices
■ Generic frequency-hopped devices
■ Generic continuous transmitters (for example, FM phones, NTSC video devices)
■ RF jamming devices
■ 802.11FH devices
■ Analog video devices
Trang 4The Spectrum Views create plots and charts for a direct view into the RF spectrum, includ-ing measurements of RF power and network device activity The plots are especially useful
to trained RF engineers, and the charts are informative for both the expert RF engineer and the generalist network engineer
An Alarms Setting configures enterprise-specific alerts and alarm triggers to notify you when wireless network is at critical utilization points
All this is integrated with Cisco WCS and is based on obtaining a license to integrate it
Trang 5Exam Preparation Tasks
Review All the Key Topics
Review the most important topics from this chapter, noted with the Key Topics icon in the outer margin of the page Table 20-3 lists a reference of these key topics and the page number where you can find each one
Complete the Tables and Lists from Memory
Print a copy of Appendix B, “Memory Tables,” (found on the CD) or at least the section for this chapter, and complete the tables and lists from memory Appendix C, “Memory Tables Answer Key,” also on the CD, includes completed tables and lists to check your work
Table 20-3 Key Topics for Chapter 20
Paragraph from the section
“Common Client-Side Issues”
Discussion of the Hidden Node issue
410
Paragraph from the section
“Common Client-Side Issues”
Discussion of the Exposed Node issue
410
Paragraph from the section
“Common Client-Side Issues”
Discussion of the Near/Far issue 410
Trang 6Definition of Key Terms
Define the following key terms from this chapter, and check your answers in the Glossary:
Hidden Node issue, Exposed Node issue
References
“Troubleshooting TechNotes” at Cisco.com: http://tinyurl.com/6dqxj2
“Troubleshooting Connectivity in a Wireless LAN Network” at Cisco.com: http://tinyurl
com/6l2ob2 The Cisco Spectrum Expert at Cisco.com: http://tinyurl.com/5eja7f
Trang 8Chapter 21 Final Preparation
Part IV: Final Preparation
Trang 10Final Preparation
This book has covered the technologies, protocols, commands, and features required for you to be prepared to pass the CCNA Wireless exam Although this book supplies de-tailed information, most people need more preparation than simply reading a book This chapter details a set of tools and a study plan that can help you complete your preparation for the exam
If you’re preparing for the CCNA Wireless exam, you should have already passed the CCNA level exams, either the CCNA exam or the ICND1 and ICND2 exams For information on passing the CCNA exams, refer to CCENT/CCNA ICND1 Official Exam Certification Guide
or CCNA ICND2 Official Exam Certification Guide, or go to http://www.cisco.com/go/ccna
This short chapter has two main sections The first lists the exam preparation tools that are useful at this point in your study process The second section lists a suggested study plan now that you have completed the rest of the chapters
Note: This chapter refers to many of the chapters and appendixes included with this book, as well as tools available on the CD Appendixes B and C are included only on the CD that comes with this book To access those, just insert the CD and make the appropriate se-lection from the opening interface
Tools for Final Preparation
This section describes the available tools and how to access them
Exam Engine and Questions on the CD
The CD in the back of the book includes an exam engine—software that displays and grades a set of exam-realistic questions The question database includes simulation (sim) questions, drag-and-drop questions, and many scenario-based questions that require the same level of analysis as the questions on the CCNA Wireless exam Using the exam en-gine, you can either study by practicing using the questions in Study Mode, or take a sim-ulated (timed) CCNA Wireless exam
The installation process has two major steps The CD in the back of this book has a recent copy of the exam engine software, supplied by Boson Software (http://www.boson.com)
The practice exam—the database of CCNA Wireless exam questions—is not on the CD
Instead, the practice exam resides on the www.boson.com web server, so the second ma-jor step is to activate and download the practice exam