Port Flap Alerts

A Port Flap alert is triggered when a switch port goes up and down repeatedly within a short period of time. By default, an alert is generated when a port flaps 40 times or more within 10 minutes. Users can configure custom thresholds based on their requirements; however, HPE recommends keeping the default threshold to avoid excessive alert noise. Port flapping typically indicates an unstable physical or logical connection that requires investigation.

Alert Triggering and Clearing Conditions

  • Triggering Condition—The alert is triggered when a port flaps 40 or more times within 10 minutes.

  • Clearing Condition—The alert automatically clears when the number of flap events falls below the configured threshold.

Common Causes

Port flaps can occur due to several reasons, including:

  • Faulty or damaged cables

  • Loose connectors

  • Bad transceivers

  • Incorrect STP or topology settings

  • Duplex mismatches

  • Physical link disturbances or environmental issues

  • Defective hardware such as NICs or switch ports

Alert Behavior

When a Port Flap alert is triggered:

  • Aruba Central evaluates the interface health and flags the affected port.

  • Under the Root Cause and Action section, you can run a cable test directly on the impacted port to validate physical connectivity issues.

  • The alert’s detailed view highlights the impacted interface, provides a summary of flap occurrences, and suggests recommended next steps.

Recommended Actions

When you receive a Port Flap alert:

  • Inspect the physical cable for damage, looseness, or improper seating.

  • Replace transceivers if optical interfaces are involved.

  • Check for loops or topology changes if STP is enabled.

  • Verify interface configuration, including speed or duplex settings.

  • Run a cable test from the Aruba Central Interface Card to validate physical layer health.

  • Monitor the port after corrective actions to ensure the flapping stops.

Related Events

The alert is associated with repeated link up and link down events observed on the affected interface within the defined time interval.

Additional Notes

Port flap alerts are generated per interface. Alerts may suppress automatically if the condition clears. Excessive port flaps may impact network performance and should be addressed promptly.