Ubuntu 18.04 LTS – cloud-init network overrides break static IP settings – Fix & Prevention

📖 ~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

Manual netplan static IP changes disappear after reboot.

Environment & Reproduction

Cloud image of Ubuntu 20.04 with default cloud-init network handling.

Root Cause Analysis

cloud-init re-renders network files from datasource metadata on boot.

Quick Triage

Inspect /etc/cloud/cloud.cfg.d and generated netplan comments for origin clues.

Step-by-Step Diagnosis

Confirm whether cloud-init owns networking and identify datasource behavior.

Solution – Primary Fix

Disable cloud-init network config and maintain static settings in netplan.

Solution – Alternative Approaches

Update datasource metadata to provide desired persistent addressing.

Verification & Acceptance Criteria

Reboots retain static IP configuration without regeneration.

Rollback Plan

Re-enable cloud-init networking if dynamic provisioning is required.

Prevention & Hardening

Define network ownership policy in golden images and deployment templates.

Related Errors & Cross-Refs

Interface renaming and route drift can occur with repeated regenerations.

Related tutorial: View the step-by-step tutorial for Ubuntu 18.04 LTS.

View all Ubuntu 18.04 LTS tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

Ubuntu cloud-init networking behavior and disable mechanisms.