IBM AIX 7.1 – Common Problem 109 – Diagnosis and Fix

📖 ~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

errpt shows GOENT_LINK_DOWN and en0 cannot ping the gateway.

Environment & Reproduction

Physical adapter on Power frame or virtual ent on VIOS misconfigured.

Root Cause Analysis

Auto-negotiation or VLAN tagging mismatch between adapter and switch.

Quick Triage

Run netstat -in and ifconfig en0 to confirm flags and IP status.

Step-by-Step Diagnosis

Use entstat -d ent0 to view link state, media speed and VLAN settings.

Solution – Primary Fix

Hard-set media with chdev -l ent0 -a media_speed=Auto_Negotiation -P then reboot.

Solution – Alternative Approaches

Migrate the IP to a SEA failover adapter if a single SEA path is down.

Verification & Acceptance Criteria

ifconfig en0 shows UP RUNNING and ping to the gateway succeeds.

Rollback Plan

Revert chdev attributes with chdev -l ent0 -a media_speed=Previous -P.

Prevention & Hardening

Document switch port settings and monitor entstat link state in nmon.

Related Errors & Cross-Refs

Often paired with EC_INTR_ERR or SEA failover messages on VIOS.

Related tutorial: View the step-by-step tutorial for aix-7.1.

View all aix-7.1 tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

IBM Docs: ent/en adapter attributes, entstat, SEA configuration.