TROUBLESHOOTING%20BASICS:%20UNIX%20EDITION

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TROUBLESHOOTING BASICS UNIX EDITION
or, two tin cans a string

• Presented By John Kernitzki
• Blackboard Global Services

April 13, 2005
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Purpose

• Aid in Fault Isolation, Identification, Repair,
  and Resolution in an orderly and reproducible
  manner.
• Think of your own experiences (well share at the
  end!)

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Todays Plan

• Fault Type Identification
• Nature
• Major Symptoms
• Fault Method Identification
• Physical/Mechanical
• Logical/Software
• Combination
• Fault Isolation Techniques

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Fundamental Points

• Troubleshooting Philosophy
• Start at one end!
• Simple to complex
• Consistent, reproducible
• Most Important Tools
• Brain
• Experience
• Fellow Users

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Fault Type Identification

• Nature
• Single Reader
• Entire Loop
• Major Symptoms
• Total Loss of Connectivity
• Bouncing
• Intermittent Faults (Periodic Invalids, etc.)

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Fault Method Identification

• Physical or Mechanical
• Faulty/Failed Termination
• Power
• Logical
• Application/Software/OS
• Reader/Location Config
• Combination
• Router Config, etc.

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Fault Isolation

• Change Management
• What Changed?
• Isolation Techniques
• Last Known Good Point
• Segment the Problem

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Fault Isolation

• Process of Elimination
• Swap known good for suspect
• Verify EVERYTHING
• Dont rely on memory alone

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Common Problems

• Reader Config (address, net, baud)
• SW Config (Location, Schedule, Type)
• IP/IPC Config
• Local Termination
• Closet Termination
• Collocated power

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Open Forum

• Case Studies
• Shared Experiences
• Q A

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Conclusion

• Fault Type Identification
• Nature
• Major Symptoms
• Fault Method Identification
• Physical/Mechanical
• Logical/Software
• Combination
• Fault Isolation Techniques

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• Thanks for coming!