在网络节点配置内核参数：
vi /etc/sysctl.conf
net.ipv4.ip_forward=1
net.ipv4.conf.all.rp_filter=0
net.ipv4.conf.default.rp_filter=0

在网络节点使内核参数立即生效：
sysctl -p

在网络节点安装软件：
yum install -y openstack-neutron openstack-neutron-ml2 openstack-neutron-openvswitch

在网络节点修改配置文件：
openstack-config --set /etc/neutron/neutron.conf DEFAULT rpc_backend rabbit
openstack-config --set /etc/neutron/neutron.conf DEFAULT rabbit_password 123456
openstack-config --set /etc/neutron/neutron.conf DEFAULT rabbit_hosts controller1:5672,controller2:5672,controller3:5672
openstack-config --set /etc/neutron/neutron.conf DEFAULT rabbit_retry_interval 1
openstack-config --set /etc/neutron/neutron.conf DEFAULT rabbit_retry_backoff 2
openstack-config --set /etc/neutron/neutron.conf DEFAULT rabbit_max_retries 0
openstack-config --set /etc/neutron/neutron.conf DEFAULT rabbit_durable_queues true
openstack-config --set /etc/neutron/neutron.conf DEFAULT rabbit_ha_queues true

openstack-config --set /etc/neutron/neutron.conf DEFAULT auth_strategy keystone
openstack-config --set /etc/neutron/neutron.conf keystone_authtoken auth_uri http://myvip:5000/v2.0
openstack-config --set /etc/neutron/neutron.conf keystone_authtoken identity_uri http://myvip:35357
openstack-config --set /etc/neutron/neutron.conf keystone_authtoken admin_user neutron
openstack-config --set /etc/neutron/neutron.conf keystone_authtoken admin_tenant_name service
openstack-config --set /etc/neutron/neutron.conf keystone_authtoken admin_password 123456
openstack-config --set /etc/neutron/neutron.conf DEFAULT core_plugin ml2
openstack-config --set /etc/neutron/neutron.conf DEFAULT service_plugins router
openstack-config --set /etc/neutron/neutron.conf DEFAULT allow_overlapping_ips True
openstack-config --set /etc/neutron/neutron.conf DEFAULT verbose True

openstack-config --set /etc/neutron/plugins/ml2/ml2_conf.ini ml2 type_drivers flat,gre
openstack-config --set /etc/neutron/plugins/ml2/ml2_conf.ini ml2 tenant_network_types gre
openstack-config --set /etc/neutron/plugins/ml2/ml2_conf.ini ml2 mechanism_drivers openvswitch
openstack-config --set /etc/neutron/plugins/ml2/ml2_conf.ini ml2_type_flat flat_networks external
openstack-config --set /etc/neutron/plugins/ml2/ml2_conf.ini ml2_type_gre tunnel_id_ranges 1:1000
openstack-config --set /etc/neutron/plugins/ml2/ml2_conf.ini securitygroup enable_security_group True
openstack-config --set /etc/neutron/plugins/ml2/ml2_conf.ini securitygroup enable_ipset True
openstack-config --set /etc/neutron/plugins/ml2/ml2_conf.ini securitygroup firewall_driver neutron.agent.linux.iptables_firewall.OVSHybridIptablesFirewallDriver
openstack-config --set /etc/neutron/plugins/ml2/ml2_conf.ini ovs local_ip 10.0.0.21
openstack-config --set /etc/neutron/plugins/ml2/ml2_conf.ini ovs bridge_mappings external:br-ex
openstack-config --set /etc/neutron/plugins/ml2/ml2_conf.ini agent tunnel_types gre

openstack-config --set /etc/neutron/l3_agent.ini DEFAULT interface_driver neutron.agent.linux.interface.OVSInterfaceDriver
openstack-config --set /etc/neutron/l3_agent.ini DEFAULT use_namespaces True
openstack-config --set /etc/neutron/l3_agent.ini DEFAULT external_network_bridge br-ex
openstack-config --set /etc/neutron/l3_agent.ini DEFAULT router_delete_namespaces True
openstack-config --set /etc/neutron/l3_agent.ini DEFAULT verbose True

openstack-config --set /etc/neutron/dhcp_agent.ini DEFAULT interface_driver neutron.agent.linux.interface.OVSInterfaceDriver
openstack-config --set /etc/neutron/dhcp_agent.ini DEFAULT dhcp_driver neutron.agent.linux.dhcp.Dnsmasq
openstack-config --set /etc/neutron/dhcp_agent.ini DEFAULT dhcp_delete_namespaces True
openstack-config --set /etc/neutron/dhcp_agent.ini DEFAULT use_namespaces True
openstack-config --set /etc/neutron/dhcp_agent.ini DEFAULT verbose True

openstack-config --set /etc/neutron/dhcp_agent.ini DEFAULT dnsmasq_config_file /etc/neutron/dnsmasq-neutron.conf
vi /etc/neutron/dnsmasq-neutron.conf
dhcp-option-force=26,1454
pkill dnsmasq

openstack-config --set /etc/neutron/metadata_agent.ini DEFAULT auth_url http://myvip:5000/v2.0
openstack-config --set /etc/neutron/metadata_agent.ini DEFAULT auth_region regionOne
openstack-config --set /etc/neutron/metadata_agent.ini DEFAULT project_name service
openstack-config --set /etc/neutron/metadata_agent.ini DEFAULT username neutron
openstack-config --set /etc/neutron/metadata_agent.ini DEFAULT password 123456
openstack-config --set /etc/neutron/metadata_agent.ini DEFAULT nova_metadata_ip myvip
openstack-config --set /etc/neutron/metadata_agent.ini DEFAULT metadata_proxy_shared_secret METADATA_SECRET
openstack-config --set /etc/neutron/metadata_agent.ini DEFAULT verbose True

在控制节点修改配置文件：
openstack-config --set /etc/nova/nova.conf neutronservice_metadata_proxy True
openstack-config --set /etc/nova/nova.conf neutronmetadata_proxy_shared_secret METADATA_SECRET

重启控制节点nova服务：
systemctl restart openstack-nova-api.service

在网络节点：
systemctl enable openvswitch.service
systemctl start openvswitch.service

ovs-vsctl add-br br-ex
ovs-vsctl add-port br-ex INTERFACE_NAME
ethtool -K INTERFACE_NAME gro off

ln -s /etc/neutron/plugins/ml2/ml2_conf.ini /etc/neutron/plugin.ini
cp /usr/lib/systemd/system/neutron-openvswitch-agent.service \
  /usr/lib/systemd/system/neutron-openvswitch-agent.service.orig
sed -i 's,plugins/openvswitch/ovs_neutron_plugin.ini,plugin.ini,g' \
  /usr/lib/systemd/system/neutron-openvswitch-agent.service

systemctl enable neutron-openvswitch-agent.service neutron-l3-agent.service neutron-dhcp-agent.service neutron-metadata-agent.service neutron-ovs-cleanup.service
systemctl start neutron-openvswitch-agent.service neutron-l3-agent.service neutron-dhcp-agent.service neutron-metadata-agent.service

验证：
source admin-openrc.sh
neutron agent-list