Ubuntu 22.04 LTS – DNS resolution fails with systemd-resolved stub issues – Fix & Prevention (FIX-PREVENTION-2)

📖 ~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

Hosts cannot resolve domain names despite basic IP connectivity.

Environment & Reproduction

Ubuntu 22.04 system using systemd-resolved with stale or invalid DNS upstream settings.

Root Cause Analysis

The local stub resolver at 127.0.0.53 cannot reach configured name servers or has broken state.

Quick Triage

Check resolvectl status and inspect /etc/resolv.conf symlink target.

Step-by-Step Diagnosis

Test queries with resolvectl query and review journalctl -u systemd-resolved.

Solution – Primary Fix

Set valid DNS servers via netplan, restart systemd-resolved, and verify /etc/resolv.conf points to stub resolver.

Solution – Alternative Approaches

For special cases, disable stub listener and use static resolv.conf managed by automation.

Verification & Acceptance Criteria

resolvectl query resolves internal and external records reliably.

Rollback Plan

Restore prior netplan DNS settings and restart systemd-resolved.

Prevention & Hardening

Standardize DNS policy and monitor resolver service health.

Related Errors & Cross-Refs

Transient network timeouts and apt mirror failures can be downstream symptoms.

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

Ubuntu 22.04 systemd-resolved and netplan DNS configuration docs.