Ubuntu 22.04 LTS – cloud-init reconfigures networking unexpectedly – 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 network settings revert after reboot, causing IP drift and service interruptions.

Environment & Reproduction

Typical on cloud images where cloud-init remains active after conversion to long-lived servers.

Root Cause Analysis

cloud-init datasource metadata applies boot-time network templates that override local netplan customizations.

Quick Triage

Identify whether active netplan file is cloud-init generated.

Step-by-Step Diagnosis

Review cloud-init logs and datasource state to verify repeated network rendering.

Solution – Primary Fix

Disable cloud-init network rendering and apply controlled netplan configuration.

Solution – Alternative Approaches

Keep cloud-init but provide explicit datasource network config that matches desired static settings.

Verification & Acceptance Criteria

Reboots preserve intended netplan state and cloud-init no longer rewrites network files.

Rollback Plan

Remove disable file and rerun cloud-init clean/init if reverting to cloud-managed lifecycle.

Prevention & Hardening

Decide ownership of network config early in image lifecycle and enforce via provisioning policy.

Related Errors & Cross-Refs

Related to DNS regressions, interface renaming issues, and boot-time route loss.

Related tutorial: View the step-by-step tutorial for Ubuntu 22.04 LTS.

View all Ubuntu 22.04 LTS tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

cloud-init and Ubuntu netplan documentation for persistent network configuration.