How to set metric in OS moderated with NetworkManager

ubuntu network metric route networkmanager

Ubuntu 20.04 desktop is using NetworkManager. Here is how to change the metric on CLI.

List connections

~  sudo nmcli connection                                                                                                                                                                                      
NAME                UUID                                  TYPE      DEVICE
Wired connection 1  72375b91-f2de-3578-9d67-53a858274d98  ethernet  enp1s0  
br-880ef0d795b5     8cc8bc46-b993-48fe-a0cd-fcd79d3d1219  bridge    br-880ef0d795b5
br-9d2f41504a75     5e5f7b3b-75a4-440f-b9b5-e7daf9654745  bridge    br-9d2f41504a75
Wired connection 2  fbe3615c-f9ab-3330-8f06-6e53a6cc8d25  ethernet  enp2s0 
docker0             0d1615ea-e595-477c-b92d-584274f7df7e  bridge    docker0  

Edit connection by name

~  sudo nmcli connection edit "Wired connection 1" 
===| nmcli interactive connection editor |=== 

Editing existing '802-3-ethernet' connection: 'Wired connection 1'

Type 'help' or '?' for available commands. 
Type 'print' to show all the connection properties. 
Type 'describe [<setting>.<prop>]' for detailed property description.  
    
You may edit the following settings: connection, 802-3-ethernet (ethernet), 802-1x, dcb, sriov, ethtool, match, ipv4, ipv6, tc, proxy   
nmcli> set ipv4.route-metric 500 
nmcli> save   
Connection 'Wired connection 1' (72375b91-f2de-3578-9d67-53a858274d98) successfully updated.  
nmcli> quit    

Restart NetworkManager

~  sudo systemctl restart NetworkManager 

Check results

~  ip r 
default via 192.168.122.1 dev enp1s0 proto dhcp metric 100                                                 
default via 192.168.68.254 dev enp2s0 proto dhcp metric 101                                                  
default via 192.168.122.1 dev enp1s0 proto dhcp metric 500                                                 
192.168.68.0/24 dev enp2s0 proto kernel scope link src 192.168.68.219 metric 101                               
169.254.0.0/16 dev enp1s0 scope link metric 1000                                                           
172.17.0.0/16 dev docker0 proto kernel scope link src 172.17.0.1 linkdown                                  
172.18.0.0/16 dev br-9d2f41504a75 proto kernel scope link src 172.18.0.1                                   
192.168.49.0/24 dev br-880ef0d795b5 proto kernel scope link src 192.168.49.1                               
192.168.122.0/24 dev enp1s0 proto kernel scope link src 192.168.122.19 metric 100                          
192.168.122.0/24 dev enp1s0 proto kernel scope link src 192.168.122.19 metric 500 

The routes for 192.168.122.1 are duplicated. After disable the device enp1s0 and re-enable it, problem solved.

Reference

https://dev.to/emamirazavi/how-to-set-metric-in-networkmanager-system-4525

Written on April 13, 2021