Verify switch port configuration If optical attenuation is normal but the link still fails, check the switch port settings: • Some switches use combo SFP/RJ45 ports, which require manual optical port configuration. • Some ports are multi-rate multiplexed (e. The transmitted optical power is too low or too high. The optical modules connected at both. Based on typical issues encountered with optical modules in daily switch applications, this document summarizes basic troubleshooting steps for resolving common faults: 1. In both devices, we have experienced episodes of SFP port lockup, requiring a full reboot of the switch to restore connectivity — even applying shutdown / no shutdown on the affected interface does not resolve the issue. Maintenance personnel should regularly check for loose, contaminated, or damaged ports to ensure proper fiber jumper connections. This is typically due to one of the following failures: hardware defect, poor seating, or incompatibility.
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