Switch Connections; Bad Or Damaged Cable; Ethernet And Fiber-Optic Cables; Link Status - Cisco Catalyst 2960X-48FPD-L Hardware Installation Manual

Switch Connections

Switch Connections

Bad or Damaged Cable

Always 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 situation because the port has many packet errors or the port constantly flaps (loses and
regains link).
• Examine or exchange the copper or fiber-optic cable with a known, good cable.
• Look for broken or missing pins on cable connectors.
• Rule out any bad patch panel connections or media convertors between the source and the destination.
• Try the cable in another port or interface, if possible, to see if the problem follows the cable.
• Remove and inspect the stack cable and stack port for bent pins or damaged connectors. If the cable is

Ethernet and Fiber-Optic Cables

Make sure that you have the correct cable for the connection.
• For Ethernet, use Category 3 copper cable for 10 Mb/s UTP connections. Use either Category 5, Category
• For fiber-optic cables, verify that you have the correct cable for the distance and port type. Make sure
• For copper connections, determine if a crossover cable was used when a straight-through was required

Link Status

Verify that both sides have link. A single broken wire or a shutdown port can cause one side to show link
even though the other side does not have link.
A port LED that is on does not guarantee that the cable is fully functional. The cable might have encountered
physical stress that causes 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.
• Make sure that both ends of the cable are connected to the correct ports.
• Verify that both devices have power.
• Verify that you are using the correct cable type.
• Look for loose connections. Sometimes a cable appears to be seated, but is not. Disconnect the cable
Catalyst 2960-X and 2960-XR Switch Hardware Installation Guide
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If possible, bypass the patch panel, or eliminate faulty media convertors (fiber-optic-to-copper).
bad, replace it with a known good cable.
5e, or Category 6 UTP for 10/100/1000 Mb/s connections.
that the connected device ports both match and use the same type encoding, optical frequency, and fiber
type.
or the reverse. Enable auto-MDIX on the switch, or replace the cable.
and then reconnect it.
Troubleshooting
OL-28309-02