SFP or XFP LED is Off

Chapter 4: Troubleshooting

When a fiber optic port on the switch is connected to a properly operating end node, the Link LED for the port should be on. If a Link LED is off, do the following:

Verify that the end node connected to the port is powered ON and is operating properly.

Check that the fiber optic cable is securely connected to the port on the switch and the port on the end node.

If the fiber optic port is on a SFP or XFP transceiver, check that the transceiver is firmly inserted into the slot on the switch.

Make sure that you are using the appropriate type of fiber optic cable and that the cable length does not exceed the allowed maximum distance. For cable specifications for an SFP transceiver, refer to the installation instructions shipped with the module.

Use a fiber optic tester to test the attenuation on the cable and the strength of the optical signal. For operating specifications for an SFP transceiver, refer to the installation instructions shipped with the module.

Check that the operating specifications (for instance, wavelength and maximum operating distance) of the fiber optic port on the remote end node are compatible with the fiber optic port on the switch.

Check that the fiber optic ports on the switch and on the end node are operating at the same speed and duplex mode.

A fiber optic cable contains two separate fiber strands. One strand is for receiving data and the other is for transmitting data. When you connect a fiber optic cable to a port, be sure that the receive fiber connector is connected to the transmit connector on the remote end node. In addition, check that the transmit fiber connector is connected to the receive connector on the remote node.

Note

The L/A LED for an SFP transceiver slot may remain ON if you remove the transceiver when it has a link to an end node without first disconnecting the fiber optic cable. The L/A LED will change to OFF the next time an SFP module is installed in the slot. To avoid this, always disconnect the fiber optic cable before removing a transceiver.