Oracle Linux 10 – static routes disappear because nm-cloud-setup overwrites networking – Fix & Prevention

📖 ~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

Custom static routes vanish after boot, breaking connectivity to backend networks.

Environment & Reproduction

Seen mostly on cloud images with nm-cloud-setup enabled.

ip route
systemctl status nm-cloud-setup.service

Root Cause Analysis

Cloud network automation reapplies metadata-derived routes over local static definitions.

Quick Triage

Check cloud-setup timers and NetworkManager logs.

systemctl list-timers | grep nm-cloud
journalctl -u NetworkManager -n 80

Step-by-Step Diagnosis

Track route table changes after cloud setup runs.

journalctl -u nm-cloud-setup -n 100
ip monitor route

Solution – Primary Fix

Disable nm-cloud-setup when static routes are authoritative.

sudo systemctl disable --now nm-cloud-setup.service nm-cloud-setup.timer
sudo nmcli connection modify prod-lan +ipv4.routes '10.20.0.0/16 10.10.10.1'
sudo systemctl restart NetworkManager

Solution – Alternative Approaches

Keep cloud setup enabled but encode routes in cloud metadata if platform supports it.

Verification & Acceptance Criteria

Routes persist across reboot and no unexpected rewrites occur.

reboot
ip route

Rollback Plan

Re-enable nm-cloud-setup if dynamic cloud-managed networking is required.

sudo systemctl enable --now nm-cloud-setup.timer

Prevention & Hardening

Decide one source of truth for routes and enforce with host profiles.

Related Errors & Cross-Refs

Often coupled with DNS override and default gateway flapping.

Related tutorial: View the step-by-step tutorial for oracle-linux-10.

View all oracle-linux-10 tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

NetworkManager cloud integration behavior on RHEL images.