🟠 High   ⏱ 5–30 min  Last verified: 19 May 2026
Affected versions: IBM AIX 7.3

📖 ~1 min read

Table of contents
  1. Symptom & Impact
  2. Environment & Reproduction
  3. Root Cause Analysis
  4. Quick Triage
  5. Step-by-Step Diagnosis
  6. Solution – Primary Fix
  7. Solution – Alternative Approaches
  8. Verification & Acceptance Criteria
  9. Rollback Plan
  10. Prevention & Hardening
  11. Related Errors & Cross-Refs
  12. References & Further Reading

Symptom & Impact

entstat shows repeated link up/down on EtherChannel ent0.

Environment & Reproduction

Mismatch with switch LACP/etherchannel mode after change.

Root Cause Analysis

AIX EC and switch port channel modes disagree (active vs on).

Quick Triage

Run entstat -d entN and lsattr -El entN for mode/hash.

Step-by-Step Diagnosis

Inspect switch CLI ‘show etherchannel summary’ for member state.

Illustrative mockup for aix-7.3 — etherchannel_link_flap_diag
Diagnostic view for etherchannel-link-flap — Illustrative mockup — Progressive Robot

Solution – Primary Fix

Set mode with chdev -l entN -a mode=8023ad -P then reboot/cfgmgr.

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Illustrative mockup for aix-7.3 — etherchannel_link_flap_fix
Remediation steps for etherchannel-link-flap — Illustrative mockup — Progressive Robot

Solution – Alternative Approaches

Temporarily detach adapter via /usr/lib/methods/ethchan_config -d.

Verification & Acceptance Criteria

entstat shows stable LACP state and zero flaps for 24h.

Rollback Plan

Revert mode and reboot if app traffic degrades.

Prevention & Hardening

Standardize LACP across NIM-built LPARs.

Pairs with VIO Server SEA failover loops.

Related tutorial: View the step-by-step tutorial for aix-7.3.

View all aix-7.3 tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

IBM Docs: EtherChannel, ethchan_config.

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