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

After reboot the LPAR cannot reach the gateway and `netstat -nr` shows no default route.

Environment & Reproduction

AIX 7.3 with `chdev -l inet0` route configured but `/etc/rc.net` overrides it.

Root Cause Analysis

Static route in ODM was not made persistent or was clobbered by a duplicate `chdev`.

Quick Triage

Run `netstat -nr`, `lsattr -El inet0` and inspect `/etc/rc.net` and `/etc/netsvc.conf`.

Step-by-Step Diagnosis

Capture `odmget -q ‘name=inet0’ CuAt` to verify the route stanza is present.

Illustrative mockup for aix-7.3 — network_no-default-route_terminal
Terminal diagnostics for Missing default route after reboot on IBM AIX 7.3 — Illustrative mockup — Progressive Robot

Solution – Primary Fix

Add the route persistently: `chdev -l inet0 -a route=net,-hopcount,0,,0,`.

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Illustrative mockup for aix-7.3 — network_no-default-route_logs
Logs and evidence for Missing default route after reboot on IBM AIX 7.3 — Illustrative mockup — Progressive Robot

Solution – Alternative Approaches

Use `mkdev -l inet0` after editing `rc.net` if the customer manages routes there.

Verification & Acceptance Criteria

`netstat -nr` shows the default route after a reboot test and pings to the gateway succeed.

Rollback Plan

Remove the route stanza with `chdev -l inet0 -a delroute=…` and revert `rc.net`.

Prevention & Hardening

Standardise on ODM-managed routes and lock down `rc.net` via configuration management.

Related to `route: 0815-061` and `if_config` start failures during `cfgmgr`.

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: AIX 7.3 TCP/IP configuration, `chdev inet0`, `/etc/rc.net`.

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