C H A P T E R
4
Troubleshooting
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Troubleshooting
This chapter provides troubleshooting recommendations.
Diagnosing Problems
The switch LEDs provide troubleshooting information about the switch. They show boot fast failures,
port-connectivity problems, and overall switch performance. You can also get statistics from Device Manager,
the CLI, or an SNMP workstation.
Switch Connections
Bad or Damaged Cable
Examine the cable for marginal damage or failure. A cable might be just good enough to connect at the physical
layer, but it could corrupt packets as a result of subtle damage to the wiring or connectors. You can identify
this problem because the port has many packet errors or it constantly flaps (loses and regains link).
• Exchange the cable with a known good cable.
• Look for broken or missing pins on cable connectors.
• Rule out any bad patch panel connections or media converters between the source and the destination.
If possible, bypass the patch panel.
• Try the cable in another port to see if the problem follows the cable.
Link Status
Verify that both sides have a link. A broken wire or a shutdown port can cause one side to show a link even
though the other side does not have a link.
A port LED that is on does not guarantee that the cable is functional. It might have encountered physical
stress, causing it to function at a marginal level. If the port LED does not turn on:
• Connect the cable from the switch to a known good device.
Cisco Catalyst IE3400 Heavy Duty Series Hardware Installation Guide
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