Ubuntu 14.04 LTS cannot resolve hostnames after reboot

📖 ~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

Applications fail outbound connections due to name resolution errors.

Environment & Reproduction

Ubuntu 14.04 hosts using DHCP-generated resolver settings.

Root Cause Analysis

resolv.conf overwritten with invalid nameserver or search domains.

Quick Triage

Confirm IP connectivity and isolate DNS as primary failure domain.

Step-by-Step Diagnosis

Inspect resolver file ownership and update mechanism behavior.

Solution – Primary Fix

Set persistent resolver values and restart networking components.

Solution – Alternative Approaches

Use local caching resolver with static upstream servers.

Verification & Acceptance Criteria

Repeated DNS queries resolve quickly and reliably after reboot.

Rollback Plan

Restore prior resolver hooks and previous nameserver settings.

Prevention & Hardening

Enforce DNS configuration ownership and monitor resolver drift.

Related Errors & Cross-Refs

Link to network service failures and intermittent Wi-Fi disconnects.

Related tutorial: View the step-by-step tutorial for Ubuntu 14.04 LTS.

View all Ubuntu 14.04 LTS tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

Ubuntu DNS and resolvconf management references.