1© 2003, Cisco Systems, Inc. All rights reserved.

Computer Networks 6 Troubleshooting

Layer 1

Halmstad University

Olga Torstensson

035-167575 olga.torstensson@ide.hh.se

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Upper Layer Components

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Upper Layer Components

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Equipment Indicator

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Power Failures

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Interface Status

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Interface Status

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Poor Network Performance

• Exceeding the design limits of the media

• Large collision domains in shared media networks such as CSMA/CD Ethernet

• Electromagnetic Interference (EMI) effects

• Faulty media or hardware

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Noise

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Slow or Poor Performance

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Congestion

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Faulty NIC

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Collisions

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Configuration Errors

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Network Testing Tools

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Interface Configuration Error

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Physical Layer Methodology

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IOS Commands

• interface is down, line protocol is down

• interface is up, line protocol is down