RHEL 10 – NetworkManager ignores static route after restart – 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 route works temporarily but disappears after service restart or reboot, breaking upstream connectivity.

Environment & Reproduction

Often introduced by adding route with `ip route add` instead of profile settings.

ip route show
systemctl restart NetworkManager
ip route show

Root Cause Analysis

Route was configured in runtime kernel table only and not persisted in NetworkManager connection profile.

Quick Triage

Confirm active profile and current route table.

nmcli con show --active
nmcli -f ipv4.routes con show 'prod-eth0'
journalctl -u NetworkManager -n 60 --no-pager

Step-by-Step Diagnosis

Inspect profile values and route metrics.

nmcli con show 'prod-eth0' | grep -E 'ipv4.routes|ipv4.gateway|ipv4.method'
ip -4 route list table main
firewall-cmd --get-active-zones

Solution – Primary Fix

Write the route into the NM profile and reactivate connection.

sudo nmcli con mod 'prod-eth0' +ipv4.routes '10.50.0.0/16 192.168.10.1'
sudo nmcli con down 'prod-eth0' && sudo nmcli con up 'prod-eth0'
ip route show | grep 10.50.0.0/16

Solution – Alternative Approaches

Use keyfile plugin route entries or ifcfg route scripts for legacy tooling.

sudo nmcli con mod 'prod-eth0' ipv4.route-metric 100
sudo nmcli con reload
sudo systemctl restart NetworkManager

Verification & Acceptance Criteria

Route survives restart and traffic reaches target network.

systemctl restart NetworkManager
ip route show | grep 10.50.0.0/16
ping -c 3 10.50.1.1

Rollback Plan

Remove added route if it interferes with routing policy.

sudo nmcli con mod 'prod-eth0' -ipv4.routes '10.50.0.0/16 192.168.10.1'
sudo nmcli con up 'prod-eth0'

Prevention & Hardening

Ban ad-hoc route commands in production and enforce profile-based networking changes.

nmcli -g NAME con show
nmcli -f ipv4.routes con show 'prod-eth0'

Related Errors & Cross-Refs

Related to DHCP route override, asymmetric routing, and incorrect route metric ordering.

Related tutorial: View the step-by-step tutorial for rhel-10.

View all rhel-10 tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

RHEL NetworkManager documentation for persistent route configuration and connection profiles.