Grading Checklist: Link Flaps - Bad Optic

A good response must include:

• Checked dmesg for link state change frequency and pattern
• Ran ethtool eth2 to check link status, speed, and negotiation
• Ran ethtool -m eth2 or ethtool --module-info eth2 for SFP+ diagnostics (TX/RX power, temp)
• Checked switch-side interface counters for CRC/FCS errors and input/output errors
• Identified that degraded optical power or signal integrity points to a bad cable/optic
• Proposed cable/optic replacement as the primary fix
• Suggested testing with a known-good cable to confirm the diagnosis
• Checked if the switch is logging err-disable or link-flap-detect actions
• Considered reseating the cable/optic as a first step before replacement
• Assessed application impact and proposed failover if a bonded interface or alternate path exists
• Recommended monitoring SFP+ diagnostic values (DOM) proactively
• Documented the incident for asset tracking (bad cable serial/part number)