Comment by Bernd Bausch for I install openstack-ocata in my CentOS7.2, I install the controller and compute in one node. In can not use neutron agent-list to show the agent list, there shows nothing: [root@controller ~]# neutron agent-list neutron CLI is deprecated and will be removed in the future. Use openstack CLI instead. I use vim /etc/neutron/plugins/ml2/linuxbridge_agent.ini check my linuxbridge_agent.ini: [linux_bridge] physical_interface_mappings = provider:enp2s0f0 [securitygroup] enable_security_group = True firewall_driver = neutron.agent.linux.iptables_firewall.IptablesFirewallDriver [vxlan] enable_vxlan = True local_ip = 10.1.1.120 l2_population = True In the /var/log/neutron/inuxbridge-agent.log: 2017-12-09 11:11:10.656 8506 ERROR neutron.plugins.ml2.drivers.agent._common_agent message = self.waiters.get(msg_id, timeout=timeout) 2017-12-09 11:11:10.656 8506 ERROR neutron.plugins.ml2.drivers.agent._common_agent File "/usr/lib/python2.7/site-packages/oslo_messaging/_drivers/amqpdriver.py", line 238, in get 2017-12-09 11:11:10.656 8506 ERROR neutron.plugins.ml2.drivers.agent._common_agent 'to message ID %s' % msg_id) 2017-12-09 11:11:10.656 8506 ERROR neutron.plugins.ml2.drivers.agent._common_agent MessagingTimeout: Timed out waiting for a reply to message ID 64f066e39907443ca01235bcc8d8143e 2017-12-09 11:11:10.656 8506 ERROR neutron.plugins.ml2.drivers.agent._common_agent 2017-12-09 11:11:10.658 8506 WARNING oslo.service.loopingcall [-] Function 'neutron.plugins.ml2.drivers.agent._common_agent.CommonAgentLoop._report_state' run outlasted interval by 30.07 sec 2017-12-09 11:12:10.661 8506 ERROR neutron.plugins.ml2.drivers.agent._common_agent [-] Failed reporting state! 2017-12-09 11:12:10.661 8506 ERROR neutron.plugins.ml2.drivers.agent._common_agent Traceback (most recent call last): 2017-12-09 11:12:10.661 8506 ERROR neutron.plugins.ml2.drivers.agent._common_agent File "/usr/lib/python2.7/site-packages/neutron/plugins/ml2/drivers/agent/_common_agent.py", line 131, in _report_state 2017-12-09 11:12:10.661 8506 ERROR neutron.plugins.ml2.drivers.agent._common_agent True) 2017-12-09 11:12:10.661 8506 ERROR neutron.plugins.ml2.drivers.agent._common_agent File "/usr/lib/python2.7/site-packages/neutron/agent/rpc.py", line 87, in report_state 2017-12-09 11:12:10.661 8506 ERROR neutron.plugins.ml2.drivers.agent._common_agent return method(context, 'report_state', **kwargs) 2017-12-09 11:12:10.661 8506 ERROR neutron.plugins.ml2.drivers.agent._common_agent File "/usr/lib/python2.7/site-packages/oslo_messaging/rpc/client.py", line 169, in call 2017-12-09 11:12:10.661 8506 ERROR neutron.plugins.ml2.drivers.agent._common_agent retry=self.retry) 2017-12-09 11:12:10.661 8506 ERROR neutron.plugins.ml2.drivers.agent._common_agent File "/usr/lib/python2.7/site-packages/oslo_messaging/transport.py", line 97, in _send 2017-12-09 11:12:10.661 8506 ERROR neutron.plugins.ml2.drivers.agent._common_agent timeout=timeout, retry=retry) 2017-12-09 11:12:10.661 8506 ERROR neutron.plugins.ml2.drivers.agent._common_agent File "/usr/lib/python2.7/site-packages/oslo_messaging/_drivers/amqpdriver.py", line 458, in send 2017-12-09 11:12:10.661 8506 ERROR neutron.plugins.ml2.drivers.agent._common_agent retry=retry) 2017-12-09 11:12:10.661 8506 ERROR neutron.plugins.ml2.drivers.agent._common_agent File "/usr/lib/python2.7/site-packages/oslo_messaging/_drivers/amqpdriver.py", line 447, in _send 2017-12-09 11 ... (more)

The log entry `MessagingTimeout: Timed out waiting for a reply to message` indicates a problem with the message queue config. Similar errors should be in other Neutron logs. Look for parameters *rpc_backend* and *transport_url* in neutron.conf, and any parameters named *rabbit_something*.