Ubuntu 16.04 LTS – network settings reset leaves server without persistent DNS – 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

DNS works temporarily but breaks after network service restart or reboot.

Environment & Reproduction

Ubuntu 16.04 using resolvconf with static network interfaces.

Root Cause Analysis

Manual /etc/resolv.conf edits are overwritten by resolvconf updates.

Quick Triage

Inspect symlink target and current resolvconf generated entries.

Step-by-Step Diagnosis

Check interface-level DNS settings and resolvconf hook behavior.

Solution – Primary Fix

Configure DNS in interface/resolvconf files and regenerate resolver state.

Solution – Alternative Approaches

Use local DNS forwarder with static upstream nameserver list.

Verification & Acceptance Criteria

DNS records resolve before and after reboot consistently.

Rollback Plan

Restore previous interface files and resolvconf templates from backup.

Prevention & Hardening

Avoid direct edits to generated resolver files in automation scripts.

Related Errors & Cross-Refs

Apt and time synchronization errors often expose unstable DNS.

Related tutorial: View the step-by-step tutorial for Ubuntu 16.04 LTS.

View all Ubuntu 16.04 LTS tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

Ubuntu resolvconf and networking persistence documentation.