Use the following command to restart the neutron-metadata-agent and nova-api services on the controller node and to check the services' status:

    # systemctl restart nova-api neutron-metadata-agent
    # systemctl status neutron-metadata-agent

The output should resemble the following:

The agent should be in an active (running) status. Use the openstack network agent list command to verify that the service has checked in:

A smiley face under the Alive column means that the agent is properly communicating with the neutron-server service.

If the services do not appear or have XXX under the Alive column, check the respective log files located at /var/log/neutron for assistance in troubleshooting. More information on the use of metadata can be found in Chapter 7, Attaching Instances to Networks, and later chapters.