IBM AIX 7.3 – Common Problem 019 – 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

Name resolution intermittently fails despite /etc/resolv.conf being correct.

Environment & Reproduction

IBM AIX 7.3 LPAR exhibiting DNS resolver / netcd issues under standard PowerVM workloads.

cat /etc/resolv.conf
lssrc -s netcd

Root Cause Analysis

netcd cache holds stale negative responses or DNS servers unreachable.

Quick Triage

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

lssrc -s netcd
netcdctrl -t dns -l

Step-by-Step Diagnosis

Test resolution with nslookup and inspect netcd cache.

nslookup ibm.com
netcdctrl -t dns -l

Solution – Primary Fix

Flush the netcd cache and restart the subsystem.

stopsrc -s netcd
startsrc -s netcd

Solution – Alternative Approaches

Disable netcd entirely if cache corruption recurs.

Verification & Acceptance Criteria

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

nslookup ibm.com
lssrc -s netcd

Rollback Plan

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

netcdctrl -e dns

Prevention & Hardening

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

smit namerslv  # validate /etc/netsvc.conf

Related Errors & Cross-Refs

errpt LABEL=NETCD_*; resolver timeouts

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

AIX network caching daemon (netcd)