This bug report is invalid.
I'm sorry for my mistake.
In my test environment, not-root user is not allowed to run 'ip' command.
I changed 'ip' command privilege for digging another problem, and I forgot it.
Now I fix 'ip' command privilege, and I can run the quantum-openvswitch-agent service.
Sorry for my noise and thanks for your investigation, Motoki-san.
This bug report is invalid.
I'm sorry for my mistake.
In my test environment, not-root user is not allowed to run 'ip' command.
I changed 'ip' command privilege for digging another problem, and I forgot it.
Now I fix 'ip' command privilege, and I can run the quantum- openvswitch- agent service.
Sorry for my noise and thanks for your investigation, Motoki-san.