Ubuntu 14.04 LTS DNS Resolution Fails Intermittently

📖 ~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 and package tools fail unpredictably when hostnames cannot be resolved in time.

Environment & Reproduction

Seen on hosts with DHCP-managed resolvers or unstable upstream DNS paths.

Root Cause Analysis

Resolver overrides, stale DHCP updates, and packet loss produce inconsistent name service behavior.

Quick Triage

Check current resolver list and perform repeated test queries to baseline failure rates.

Step-by-Step Diagnosis

Trace resolver source, validate network route quality, and test alternate DNS endpoints.

Solution – Primary Fix

Pin reliable resolvers and enforce persistent network manager or interface configuration.

Solution – Alternative Approaches

Deploy local caching resolver and route recursive queries through monitored internal DNS.

Verification & Acceptance Criteria

Sustained query tests complete without timeout and dependent services recover automatically.

Rollback Plan

Restore prior resolver config backup and disable experimental DNS overrides.

Prevention & Hardening

Monitor DNS latency and implement dual-path resolver policies for resilience.

Related Errors & Cross-Refs

Temporary failure in name resolution and apt mirror hostname lookup failures.

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 networking docs and resolver architecture references.