chapter 12 troubleshooting networking problems
Download
Skip this Video
Download Presentation
Chapter 12: Troubleshooting Networking Problems

Loading in 2 Seconds...

play fullscreen
1 / 56

Chapter 12: Troubleshooting Networking Problems - PowerPoint PPT Presentation


  • 197 Views
  • Uploaded on

Chapter 12: Troubleshooting Networking Problems. Network+ Guide to Networks Third Edition. Objectives:. Describe the elements of an effective troubleshooting methodology Follow a systematic troubleshooting process to solve networking problems

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Chapter 12: Troubleshooting Networking Problems' - oro


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
chapter 12 troubleshooting networking problems

Chapter 12: Troubleshooting Networking Problems

Network+ Guide to Networks

Third Edition

objectives
Objectives:
  • Describe the elements of an effective troubleshooting methodology
  • Follow a systematic troubleshooting process to solve networking problems
  • Use a variety of software and hardware tools to diagnose problems
  • Discuss practical issues related to troubleshooting
troubleshooting methodology
Troubleshooting Methodology
  • Identify the Symptoms
  • Identify the Scope of the Problem
  • Establish What Has Changed
  • Determine the Most Probable Cause
    • Verify user competency
    • Re-create the problem
    • Verify physical connectivity
    • Verify logical connectivity
troubleshooting methodology continued
Troubleshooting Methodology (continued)
  • Recognize the potential effects of a solution
  • Implement a solution
  • Test the solution
  • Document the solution
troubleshooting methodology continued6
Troubleshooting Methodology (continued)
  • Identify the Symptoms
    • Access to the network affected
    • Network performance affected
    • Data or programs affected
    • Only certain network services affected
troubleshooting methodology continued7
Troubleshooting Methodology (continued)
  • Identify the Symptoms (continued)
    • If programs are affected, does the problem include one local application, one networked application, or multiple networked applications
    • What specific error messages do users report
    • One user or are multiple users affected
    • Do symptoms manifest themselves consistently
troubleshooting methodology continued8
Troubleshooting Methodology (continued)
  • Identify the Scope of the Problem
    • How many users or network segments are affected?
      • One user or workstation?
      • A workgroup?
      • A department?
      • One location within an organization?
      • An entire organization?
troubleshooting methodology continued9
Troubleshooting Methodology (continued)
  • Identify the Scope of the Problem (continued)
    • When did the problem begin?
      • Has the network, server, or workstation ever worked properly?
      • Did the symptoms appear in the last hour or day?
      • Have the symptoms appeared intermittently for a long time?
      • Do the symptoms appear only at certain times?
troubleshooting methodology continued12
Troubleshooting Methodology (continued)
  • Establish What Has Changed
    • Did the operating system or configuration on a server, workstation, or connectivity device change?
    • Were new components added to a server, workstation, or connectivity device?
    • Were old components removed from a server, workstation, or connectivity device?
    • Were new users or segments added to the network?
troubleshooting methodology continued13
Troubleshooting Methodology (continued)
  • Establish What Has Changed (continued)
    • Was a server, workstation, or connectivity device moved from its previous location to a new location?
    • Was a server, workstation, or connectivity device replaced?
    • Was new software installed on a server, workstation, or connectivity device?
    • Was old software removed from a server, workstation, or connectivity device?
troubleshooting methodology continued14
Troubleshooting Methodology (continued)
  • Select the Most Probable Cause
    • Verify User Competency
    • Re-create the Problem
      • Can you make the symptoms recur every time?
      • If symptoms recur, are they consistent?
      • Can you make the symptoms recur some of the time?
      • Do the symptoms happen only under certain circumstances?
troubleshooting methodology continued15
Troubleshooting Methodology (continued)
  • Select the Most Probable Cause
    • Re-create the Problem (continued)
      • In the case of software malfunctions, are the symptoms consistent no matter how many and which programs or files the user has open?
      • Do the symptoms ever happen when you try to repeat them?
troubleshooting methodology continued16
Troubleshooting Methodology (continued)
  • Select the Most Probable Cause
    • Verify Physical Connectivity
      • Symptoms of Physical Layer Problems
        • Lengths exceed standards
        • Noise affecting a signal
        • Improper connections
        • Damaged cables
        • Faulty NICs
troubleshooting methodology continued17
Troubleshooting Methodology (continued)
  • Select the Most Probable Cause
    • Verify Physical Connectivity
      • Diagnosing Physical Layer Problems
        • Device turned on
        • NIC properly inserted
        • Device’s network cable properly connected
        • Patch cables properly connect
troubleshooting methodology continued18
Troubleshooting Methodology (continued)
  • Select the Most Probable Cause
    • Verify Physical Connectivity
      • Diagnosing Physical Layer Problems (continued)
        • Hub, router, or switch properly connected to the backbone
        • Cables in good condition
        • Connectors in good condition and properly seated
        • Network lengths conform to specifications?
        • Devices configured properly
troubleshooting methodology continued19
Troubleshooting Methodology (continued)
  • Select the Most Probable Cause
    • Verify Physical Connectivity
      • Swapping Equipment
        • If you suspect a problem lies with a network component
troubleshooting methodology continued21
Troubleshooting Methodology (continued)
  • Select the Most Probable Cause
    • Verify Logical Connectivity
      • Do error messages reference damaged or missing files or device drivers?
      • Do error messages reference malfunctioning or insufficient resources (such as memory)?
      • Has an operating system, configuration, or application been recently changed, introduced, or deleted?
      • Does the problem occur with only one application or a few, similar applications?
troubleshooting methodology continued22
Troubleshooting Methodology (continued)
  • Select the Most Probable Cause
    • Verify Logical Connectivity
      • Does the problem happen consistently?
      • Does the problem affect a single user or one group of users?
troubleshooting methodology continued23
Troubleshooting Methodology (continued)
  • Recognize the Potential Effects of a Solution
    • Scope
    • Tradeoffs
    • Security
    • Scalability
    • Cost
    • Using Vendor Information
troubleshooting methodology continued24
Troubleshooting Methodology (continued)
  • Implement a Solution
    • Implement a safe and reliable solution:

1. Collect documentation about a problem’s symptoms

2. Backup existing software and keep the old parts handy

3. Perform the change and record your actions

4. Test your solution

troubleshooting methodology continued25
Troubleshooting Methodology (continued)
  • Implement a Solution
    • Implement a safe and reliable solution:

5. Before leaving the area clean it up

6. Record the details you have collected about the symptoms, the problem, and the solution

7. If solution involved a significant change or problem, revisit the solution a day or two later to verify that the problem has been solved

troubleshooting methodology continued26
Troubleshooting Methodology (continued)
  • Test the Solution
  • Document Problems and Solutions
    • Staff Involved in Troubleshooting
    • Recording Problems and Resolutions
troubleshooting methodology continued27
Troubleshooting Methodology (continued)
  • A typical problem record form should include
    • The name, department, and phone number of the problem originator
    • Information regarding whether the problem is software- or hardware-related
    • If the problem is software-related, the package to which it pertains; if the problem is hardware-related, the device or component to which it pertains
troubleshooting methodology continued28
Troubleshooting Methodology (continued)
  • A typical problem record form should include (continued)
    • Symptoms of the problem, including when it was first noticed
    • The name and telephone number of the network support contact
    • The amount of time spent troubleshooting the problem
    • The resolution of the problem
troubleshooting methodology continued29
Troubleshooting Methodology (continued)
  • Notifying Others of Changes
    • A change management system
      • Adding or upgrading software
      • Adding or upgrading hardware or other devices
      • Adding new hardware
      • Changing the properties of a network device
troubleshooting methodology continued30
Troubleshooting Methodology (continued)
  • A change management system (continued)
    • Increasing or decreasing rights
    • Physically moving networked devices
    • Moving user accounts and their files/directories
    • Making changes in processes
    • Making changes in vendor policies or relationships
troubleshooting methodology continued31
Troubleshooting Methodology (continued)
  • Preventing Future Problems
    • Review the troubleshooting questions and examples
    • Predict network problems by network maintenance, documentation, security, or upgrades
troubleshooting tools
Troubleshooting Tools
  • Crossover Cable
    • Use to directly interconnect two nodes
  • Tone Generator and Tone Locator
    • Tone generator is a small electronic device that issues a signal on a wire pair
    • Tone locator is a device that emits a tone when it detects electrical activity on a wire pair
troubleshooting tools continued34
Troubleshooting Tools (continued)
  • Multimeter
    • Can measure many characteristics of an electric circuit, including its resistance and voltage
troubleshooting tools continued36
Troubleshooting Tools (continued)
  • Use a multimeter to:
    • Verify that a cable is properly conducting electricity
    • Check for the presence of noise on a wire
    • Verify that the amount of resistance on coaxial cable
    • Test for short or open circuits in the wire
troubleshooting tools continued37
Troubleshooting Tools (continued)
  • Cable Continuity Testers
    • In troubleshooting a Physical layer problem, you may find the cause of a problem by simply testing whether your cable is carrying a signal to its destination
troubleshooting tools continued39
Troubleshooting Tools (continued)
  • Cable Performance Testers
    • Measure the distance to a connectivity device, termination point, or cable fault
    • Measure attenuation along a cable
    • Measure near-end crosstalk between wires
    • Measure termination resistance and impedance
troubleshooting tools continued40
Troubleshooting Tools (continued)
  • Cable Performance Testers (continued)
    • Issue pass/fail ratings for CAT 3, CAT 5, CAT 5e, CAT 6, or CAT 7 standards
    • Store and print cable testing results or directly save data to a computer database
    • Graphically depict a cable’s attenuation and crosstalk characteristics over the length of the cable
troubleshooting tools continued42
Troubleshooting Tools (continued)
  • Network Monitors
    • Continuously monitor network traffic on a segment
    • Capture network data transmitted on a segment
    • Capture frames sent to or from a specific node
    • Reproduce network conditions
    • Generate statistics about network activity
troubleshooting tools continued43
Troubleshooting Tools (continued)
  • Network Monitors (continued)
    • Discover all network nodes on a segment
    • Establish a baseline that reflects network traffic
    • Store traffic data and generate reports
    • Trigger alarms when traffic conditions meet preconfigured conditions
troubleshooting tools continued44
Troubleshooting Tools (continued)
  • Abnormal data patterns and packets
    • Local collisions
    • Late collisions
    • Runts
    • Giants
troubleshooting tools continued45
Troubleshooting Tools (continued)
  • Abnormal data patterns and packets (continued)
    • Jabber
    • Negative frame sequence checks
    • Ghosts
  • Protocol Analyzers
    • Can capture traffic
    • Can also analyze frames
    • To Layer 7 of the OSI Model
troubleshooting tools continued47
Troubleshooting Tools (continued)
  • Wireless Network Testers
    • Learn about a wireless environment by viewing the wireless network connection properties on your workstation
troubleshooting tools continued49
Troubleshooting Tools (continued)
  • Wireless network testing tools
    • Identify transmitting APs, stations and channels
    • Measure signal strength and range
    • Indicate the effects of attenuation, signal loss, and noise
    • Interpret signal strength information
troubleshooting tools continued50
Troubleshooting Tools (continued)
  • Wireless network testing tools (continued)
    • Ensure proper association and reassociation
    • Capture and interpret traffic
    • Measure throughput and assess data
    • Analyze the characteristics of each channel
chapter summary
Chapter Summary
  • Before you can resolve a network problem, you need to determine its cause
  • Act like a doctor diagnosing a patient
  • Identify the scope of the problem
  • At each point, stop to consider
  • Ensure that the user is performing all functions correctly
chapter summary continued
Chapter Summary (continued)
  • Attempt to reproduce the problem’s symptoms
  • Check for sound connections
  • Exchange component for a functional one
  • Determine properly configured software
  • Consult vendor information
chapter summary continued54
Chapter Summary (continued)
  • Test your solution
  • Operate a help desk
  • Use a software program for documenting
  • Record details about a problem
  • Follow up
chapter summary continued55
Chapter Summary (continued)
  • Change management system
  • Tone generator and tone locator
  • Multimeter
  • Cable continuity testers
  • Cable performance tester
chapter summary continued56
Chapter Summary (continued)
  • Network monitor
  • Protocol analyzers
  • Wireless network testing tools
ad