I am using openstack yoga with kolla ansible.

When I migrate:

instance1 from host A to host B after that I cannot ping this instance(telnet also). I must restart neutron_openvswitch_agent or move this instance back to host B  then this problem has gone.

this is my settings:

----------------- neutron.conf -----------------
[nova]
live_migration_events = True
------------------------------------------------

----------------- nova.conf -----------------
[DEFAULT]
vif_plugging_timeout = 600
vif_plugging_is_fatal = False
debug = True

[compute]
live_migration_wait_for_vif_plug = True

[workarounds]
enable_qemu_monitor_announce_self = True

----------------- openvswitch_agent.ini-----------------

[securitygroup]

firewall_driver = openvswitch
[ovs]
openflow_processed_per_port = true

I check nova, neutron, ops logs but they are ok. 

Thank you.

Nguyen Huu Khoi