bach neutron # cat l3_agent.ini  |grep -v "^$"|grep -v ^#
[DEFAULT]
interface_driver = neutron.agent.linux.interface.OVSInterfaceDriver
use_namespaces = True
external_network_bridge =
router_delete_namespaces = True

bach neutron # cat ./plugins/ml2/ml2_conf.ini  |grep -v "^$"|grep -v ^#
[ml2]
type_drivers = flat,gre
tenant_network_types = gre
mechanism_drivers = openvswitch,l2population
[ml2_type_flat]
flat_networks = external
[ml2_type_vlan]
[ml2_type_gre]
tunnel_id_ranges = 1:1000
[ml2_type_vxlan]
[securitygroup]
enable_security_group = True
enable_ipset = True
firewall_driver = neutron.agent.linux.iptables_firewall.OVSHybridIptablesFirewallDriver
[ovs]
local_ip = 10.11.3.10
enable_tunneling = True
bridge_mappings = external:br-ex
[agent]
l2population = True
tunnel_types = gre
root_helper = sudo /usr/bin/neutron-rootwrap /etc/neutron/rootwrap.conf

bach neutron # ovs-vsctl  show
fded7d94-21fa-4b46-a5fd-7d06d1dd0de2
    Bridge br-ex
        Port "enp2s0"
            Interface "enp2s0"
        Port br-ex
            Interface br-ex
                type: internal
    Bridge br-int
        fail_mode: secure
        Port br-int
            Interface br-int
                type: internal
        Port "tap40e0b0f0-42"
            tag: 4095
            Interface "tap40e0b0f0-42"
                type: internal
        Port "qg-e02ad6f6-e3"
            tag: 4095
            Interface "qg-e02ad6f6-e3"
                type: internal
        Port "qr-f4c4c56a-d6"
            tag: 4095
            Interface "qr-f4c4c56a-d6"
                type: internal