1. 1 © 2003, Cisco Systems, Inc. All rights reserved. Computer Networks 6 Troubleshooting Layer 1 Halmstad University Olga Torstensson 035-167575 olga.torstensson@ide.hh.seolga.torstensson@ide.hh.se

2. 222 © 2003, Cisco Systems, Inc. All rights reserved. Upper Layer Components

3. 333 © 2003, Cisco Systems, Inc. All rights reserved. Upper Layer Components

4. 444 © 2003, Cisco Systems, Inc. All rights reserved. Equipment Indicator

5. 555 © 2003, Cisco Systems, Inc. All rights reserved. Power Failures

6. 666 © 2003, Cisco Systems, Inc. All rights reserved. Interface Status

7. 777 © 2003, Cisco Systems, Inc. All rights reserved. Interface Status

8. 888 © 2003, Cisco Systems, Inc. All rights reserved. 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

9. 999 © 2003, Cisco Systems, Inc. All rights reserved. Noise

10. 10 © 2003, Cisco Systems, Inc. All rights reserved. Slow or Poor Performance

11. 11 © 2003, Cisco Systems, Inc. All rights reserved. Congestion

12. 12 © 2003, Cisco Systems, Inc. All rights reserved. Faulty NIC

13. 13 © 2003, Cisco Systems, Inc. All rights reserved. Collisions

14. 14 © 2003, Cisco Systems, Inc. All rights reserved. Configuration Errors

15. 15 © 2003, Cisco Systems, Inc. All rights reserved. Network Testing Tools

16. 16 © 2003, Cisco Systems, Inc. All rights reserved. Interface Configuration Error

17. 17 © 2003, Cisco Systems, Inc. All rights reserved. Physical Layer Methodology

18. 18 © 2003, Cisco Systems, Inc. All rights reserved. IOS Commands interface is down, line protocol is down interface is up, line protocol is down