[Rdo-list] Multicast does not work with ML2/VxLAN

Hi, I am trying ML2/VXLAN on RDO Havana 2013.2.2 on CentOS 6.5 in a 3-nodes setup. OVS version is 1.11.0. I enable multicast by setting vxlan_group = 239.1.1.1 in /etc/neutron/plugins/ml2/ml2_conf.ini. But from the tcpdump, I find the VM broadcast traffic still goes via multiple unicast packages between OVS agent nodes. How to make that multicast really work ? My ml2_confi.ini: [ml2] type_drivers = vxlan tenant_network_types = vxlan mechanism_drivers = openvswitch [ml2_type_flat] [ml2_type_vlan] [ml2_type_gre] [ml2_type_vxlan] vni_ranges = 1001:2000 vxlan_group = 239.1.1.1 [database] sql_connection = mysql://neutron:83105f1d6ded47cc@10.142.0.101/neutron_ml2 [securitygroup] firewall_driver = dummy_value_to_enable_security_groups_in_server My ovs_neutron_plugin.ini on every OVS agent node: [OVS] vxlan_udp_port=4789 tunnel_type=vxlan tunnel_id_ranges=1001:2000 tenant_network_type=vxlan local_ip=10.142.255.101 #This varies on different node enable_tunneling=True [AGENT] tunnel_types = vxlan polling_interval=2 [SECURITYGROUP] firewall_driver=neutron.agent.linux.iptables_firewall.OVSHybridIptablesFirewallDriver Kimi