Debian 13 systemd-resolved DNS Resolution Failure

📖 ~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

Hostname lookups fail intermittently, affecting package updates and service discovery.

Environment & Reproduction

Often appears after VPN or DHCP DNS changes.

Root Cause Analysis

Resolver receives invalid upstream DNS or stale per-link settings.

Quick Triage

Check `/etc/resolv.conf` target and resolver service status.

Step-by-Step Diagnosis

Inspect interface DNS assignments and search domains.

Solution – Primary Fix

Restore stub resolver symlink and restart service.

Solution – Alternative Approaches

Set explicit DNS values in network profile configuration.

Verification & Acceptance Criteria

Name resolution succeeds consistently for required domains.

Rollback Plan

Revert resolver symlink and DNS profile changes if regressions occur.

Prevention & Hardening

Monitor DNS health and enforce approved resolver ordering.

Related Errors & Cross-Refs

Associated with DNSSEC validation failures and stale search suffixes.

Related tutorial: View the step-by-step tutorial for Debian 13.

View all Debian 13 tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

Debian systemd-resolved administration guide.