IBM AIX 7.3 – Common Problem 171 – 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

A static route to a partner network is missing after every reboot. Manual route add commands restore connectivity but are not persisted.

Environment & Reproduction

Occurs when routes are added via ‘route add’ instead of ‘chdev -l inet0 -a route=’.

netstat -rn
oslevel -s
uname -a

Root Cause Analysis

Cause is route not stored in ODM through inet0 attribute, so it is not reapplied at boot by /etc/rc.net.

Quick Triage

Inspect routing table and inet0 ODM definition.

netstat -rn

Step-by-Step Diagnosis

Capture deeper evidence to isolate the failure path.

netstat -rn
lsattr -El inet0
odmget -q 'name=inet0' CuAt
cat /etc/rc.net | head
errpt | head

Solution – Primary Fix

Apply the proven primary fix in a controlled change window.

chdev -l inet0 -a route=net,-static,10.10.0.0,255.255.0.0,10.0.0.1
odmget -q 'name=inet0' CuAt | head
reboot

Solution – Alternative Approaches

Use these alternatives when the primary fix is blocked by environmental constraints.

smitty mkroute
edit /etc/gateways with gated
implement RIP/OSPF via gated

Verification & Acceptance Criteria

Confirm the system meets acceptance criteria after the change.

netstat -rn | grep 10.10
ping 10.10.1.1
lsattr -El inet0 | grep route

Rollback Plan

Revert cleanly if regressions appear during validation.

chdev -l inet0 -a delroute=net,-static,10.10.0.0,255.255.0.0,10.0.0.1
route delete 10.10.0.0
reboot

Prevention & Hardening

Reduce recurrence with monitoring and preventive tuning.

infrastructure-as-code script for routes
backup ODM weekly
use smitty for changes

Related Errors & Cross-Refs

Related to multiple default gateways, IPv6 routing, and EtherChannel rebuilds removing routes.

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 AIX 7.3 TCP/IP guide, chdev and inet0 documentation.