Check optic signal levels with following command:
show ports <port_numbers> transceiver information detail
If signal levels are below Low Warning/Alarm thresholds then try following:
- Clean the fiber optic plug and adapter
- Swap out all cables and optic transceivers to verify that these are not the cause.
- Test with different ports on each end of the link.
- If the issue follows one port with known good cables and optics, contact GTAC for further troubleshooting.
If signal levels are above High Warning/Alarm thresholds then try to use optic attenuators to reduce signal level so it will stay within normal operation range.