Ethernet And Fiber-Optic Cables; Link Status; 10/100/1000 Port Connections; 10/100/1000 Poe+ Port Connections - Cisco Catalyst C3850 Series Hardware Installation Manual

Ethernet and Fiber-Optic Cables

• 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 distance and port type. Ensure that the
• 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.
• Ensure 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.
• Check for loose connections. Sometimes a cable appears to be seated, but is not. Disconnect the cable

10/100/1000 Port Connections

A port appears to malfunction:
• Use the Mode button to show the status for all ports.
• Use the show interfaces privileged EXEC command to see if the port is error-disabled, disabled, or

10/100/1000 PoE+ Port Connections

A powered device connected to a PoE port does not receive power:
• Use the Mode button to show the PoE status for all ports.
• Use the show interfaces privileged EXEC command to see if the port is in error-disabled, disabled, or
• Verify that the power supply installed in the switch meets the power requirements of your connected
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bad, replace it with a known good cable.
5e, or Category 6 UTP for 10/100/1000 Mb/s connections.
connected device ports match and use the same type of encoding, optical frequency, and fiber type.
or the reverse. Enable auto-MDIX on the switch, or replace the cable.
and then reconnect it.
shutdown. Reenable the port if necessary.
shutdown. Reenable the port if necessary.
devices.
Troubleshooting
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