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The following points summarize the key concepts of this chapter:
Understanding the Problem
- It is essential to take a structured approach to troubleshooting in order to resolve network problems.
- Collecting information lays the foundation for isolating a problem.
- Asking the users the right questions will provide the most information. Use open-ended questions.
- The troubleshooting process includes five steps: defining the problem, isolating the cause, making the repair, confirming the solution, and documenting the outcome.
- If a problem is not obvious, it will be necessary to divide the network into logical groups such as clients, adapters, hubs, cabling and connectors, servers, connectivity components, and protocols.
- Repairing network problems sometimes requires working on several problems at once. Because it is not possible to repair everything at the same time, you will need to establish priorities.
- The network administrator should establish the priorities that affect the integrity of the network.
Troubleshooting Tools
- Hardware tools are used to identify network problems, network-performance trends, and to help isolate network malfunctions.
- The most common tool for troubleshooting hardware is the digital voltmeter.
- A time-domain reflectometer (TDR) can be used to find breaks, shorts, or imperfections in network cabling.
- Some advanced cable test equipment can display message-frame counts, excess collisions, late collisions, error-frame counts, congestion errors, and beaconing.
- Oscilloscopes are used with TDRs to display precise measurements of voltage and time.
- Network monitors track all or a selected part of network traffic, while protocol analyzers perform real-time network traffic analysis.
- Network General Sniffer can decode and interpret frames from 14 protocols.
- Novell's LANanalyzer works like Sniffer, but is limited to NetWare.
- The scope of a network management program depends on the size of the network, the capability of the staff, the organizational budget, and the expectations of the users.
- Several monitoring utilities are available to manage network performance. Among these are performance monitors, network monitors, and network management protocols.
Where to Find Help
- Network technology is constantly evolving. Knowing when and where to get help is an important part of being an effective network administrator.
- Useful sources of help include bulletin board services, user groups, and periodicals.
- Joining a local users group can provide the contacts needed to solve problems.
- Internet services include WWW, FTP, e-mail, news, and Telnet.
- Dial-up lines and ISDN connections are two methods by which to physically connect to the Internet.