IBM AIX 7.2 – Common Problem 015 – 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

Applications log Name Resolution failed and host commands time out.

Environment & Reproduction

IBM AIX 7.2 LPAR exhibiting DNS / resolver failure issues under standard PowerVM workloads.

cat /etc/resolv.conf
host server1

Root Cause Analysis

/etc/netsvc.conf or /etc/irs.conf orders bind before local for hung DNS.

Quick Triage

Confirm scope with errpt, recent changes, and subsystem state via lssrc.

errpt | grep -i resolv
nsupdate -d

Step-by-Step Diagnosis

Test resolver path against each nameserver and inspect resolver order.

host -v server1 nameserver1
cat /etc/netsvc.conf

Solution – Primary Fix

Correct resolver order and refresh inetd to pick changes.

echo 'hosts=local,bind4' > /etc/netsvc.conf
refresh -s inetd

Solution – Alternative Approaches

Switch to internal cache via named-light bind on the VIO Server.

Verification & Acceptance Criteria

Confirm subsystem returns to RUNNING state and errpt shows no new entries.

host server1
host -v server1

Rollback Plan

Restore prior configuration from mksysb or alt_disk_install clone if the fix regresses.

cp /etc/netsvc.conf.bak /etc/netsvc.conf

Prevention & Hardening

Encode the fix in NIM customisation scripts and monitor via topas/nmon.

smit chinet  # set NSORDER persistently

Related Errors & Cross-Refs

errpt resolver timeouts; sendmail queue growth

Related tutorial: View the step-by-step tutorial for aix-7.2.

View all aix-7.2 tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

AIX TCP/IP Administration Guide