Legacy networking primarily involves compute nodes. However, you must configure the controller node to use it. Run the following commands: # openstack-config --set /etc/nova/nova.conf DEFAULT \ network_api_class nova.network.api.API # openstack-config --set /etc/nova/nova.conf DEFAULT \ security_group_api nova Edit the /etc/nova/nova.conf file and add the following keys to the [DEFAULT] section: [DEFAULT] ... network_api_class = nova.network.api.API security_group_api = nova Restart the Compute services: # service openstack-nova-api restart # service openstack-nova-scheduler restart # service openstack-nova-conductor restart # service nova-api restart # service nova-scheduler restart # service nova-conductor restart