📖 ~1 min read
Table of contents
Symptom & Impact
DNS lookups fail locally even though network routes are otherwise reachable.
Environment & Reproduction
Ubuntu 18.04 hosts using systemd-resolved with modified resolv.conf symlinks.
Root Cause Analysis
Stub resolver listener or resolv.conf linkage is broken, bypassing expected local DNS flow.
Quick Triage
Check resolved unit status and verify where resolv.conf points.
Step-by-Step Diagnosis
Inspect service logs, resolver links, and test direct query paths for failures.
Solution – Primary Fix
Recreate correct resolv.conf symlink, restart systemd-resolved, and reload network settings.
Still having issues? Our IT Solutions & Services team can diagnose and resolve this for you. Get in touch for a free consultation.
Solution – Alternative Approaches
Use static resolver config if local stub mode is unsuitable for deployment constraints.
Verification & Acceptance Criteria
DNS queries resolve reliably and package downloads succeed without resolver errors.
Rollback Plan
Restore previous resolver configuration if applications depend on custom DNS behavior.
Prevention & Hardening
Protect resolver symlink management in config automation and drift-detection checks.
Related Errors & Cross-Refs
Temporary failure in name resolution and localhost port 53 query failures.
Related tutorial: View the step-by-step tutorial for Ubuntu 18.04 LTS.
View all Ubuntu 18.04 LTS tutorials on the Tutorials Hub →
Browse all common problems & solutions on the Tutorials Hub.
References & Further Reading
systemd-resolved and Ubuntu netplan documentation for resolver design and recovery.
Need Expert Help?
If you cannot resolve this yourself, our team offers hands-on Server Management, Managed IT Services, and flexible Support Plans. Contact us today — we respond within one business day.
