I have the feeling that this neutron-ovs-agent is never starting properly because of this openvswitch issue ...

[root@undercloud-0-trunk stack]# systemctl | grep neutron
  neutron-dhcp-agent.service                                                          loaded active running   OpenStack Neutron DHCP Agent
  neutron-server.service                                                              loaded active running   OpenStack Neutron Server


I don't see the process as running in systemctl and:

[root@undercloud-0-trunk stack]# systemctl | grep neutron
  neutron-dhcp-agent.service                                                          loaded active running   OpenStack Neutron DHCP Agent
  neutron-server.service                                                              loaded active running   OpenStack Neutron Server
[root@undercloud-0-trunk stack]# systemctl status neutron-openvswitch-agent
● neutron-openvswitch-agent.service - OpenStack Neutron Open vSwitch Agent
   Loaded: loaded (/usr/lib/systemd/system/neutron-openvswitch-agent.service; enabled; vendor preset: disabled)
   Active: inactive (dead) since Wed 2016-12-14 00:14:46 EST; 13min ago
 Main PID: 9667 (code=exited, status=0/SUCCESS)

Dec 14 00:14:22 undercloud-0-trunk.localdomain neutron-enable-bridge-firewall.sh[9661]: net.bridge.bridge-nf-call-arptables = 1
Dec 14 00:14:22 undercloud-0-trunk.localdomain neutron-enable-bridge-firewall.sh[9661]: net.bridge.bridge-nf-call-iptables = 1
Dec 14 00:14:22 undercloud-0-trunk.localdomain systemd[1]: Started OpenStack Neutron Open vSwitch Agent.
Dec 14 00:14:22 undercloud-0-trunk.localdomain neutron-openvswitch-agent[9667]: Guru meditation now registers SIGUSR1 and SIGUSR2 by default for backward compatibility. SIGUSR1 will no longer be registered in a future rele...rate reports.
Dec 14 00:14:23 undercloud-0-trunk.localdomain neutron-openvswitch-agent[9667]: Option "verbose" from group "DEFAULT" is deprecated for removal.  Its value may be silently ignored in the future.
Dec 14 00:14:23 undercloud-0-trunk.localdomain neutron-openvswitch-agent[9667]: Option "rpc_backend" from group "DEFAULT" is deprecated for removal.  Its value may be silently ignored in the future.
Dec 14 00:14:25 undercloud-0-trunk.localdomain neutron-openvswitch-agent[9667]: Option "notification_driver" from group "DEFAULT" is deprecated. Use option "driver" from group "oslo_messaging_notifications".
Dec 14 00:14:25 undercloud-0-trunk.localdomain neutron-openvswitch-agent[9667]: Could not load neutron.openstack.common.notifier.rpc_notifier
Dec 14 00:14:25 undercloud-0-trunk.localdomain sudo[9796]:  neutron : TTY=unknown ; PWD=/ ; USER=root ; COMMAND=/bin/neutron-rootwrap-daemon /etc/neutron/rootwrap.conf
Dec 14 00:14:26 undercloud-0-trunk.localdomain ovs-vsctl[9804]: ovs|00001|vsctl|INFO|Called as /bin/ovs-vsctl --timeout=10 --oneline --format=json -- --id=@manager create Manager "target=\"ptcp:6640:127.0.0.1\"" -- add O...ptions @manager
Hint: Some lines were ellipsized, use -l to show in full.


Restarting it seems to solve it:

[root@undercloud-0-trunk stack]# systemctl restart neutron-openvswitch-agent && systemctl status neutron-openvswitch-agent
● neutron-openvswitch-agent.service - OpenStack Neutron Open vSwitch Agent
   Loaded: loaded (/usr/lib/systemd/system/neutron-openvswitch-agent.service; enabled; vendor preset: disabled)
   Active: active (running) since Wed 2016-12-14 00:28:42 EST; 38ms ago
  Process: 22767 ExecStartPre=/usr/bin/neutron-enable-bridge-firewall.sh (code=exited, status=0/SUCCESS)
 Main PID: 22774 (neutron-openvsw)
   CGroup: /system.slice/neutron-openvswitch-agent.service
           └─22774 /usr/bin/python2 /usr/bin/neutron-openvswitch-agent --config-file /usr/share/neutron/neutron-dist.conf --config-file /etc/neutron/neutron.conf --config-file /etc/neutron/plugins/ml2/openvswitch_agent.ini --config-dir...

Dec 14 00:28:42 undercloud-0-trunk.localdomain systemd[1]: Starting OpenStack Neutron Open vSwitch Agent...
Dec 14 00:28:42 undercloud-0-trunk.localdomain neutron-enable-bridge-firewall.sh[22767]: net.bridge.bridge-nf-call-arptables = 1
Dec 14 00:28:42 undercloud-0-trunk.localdomain neutron-enable-bridge-firewall.sh[22767]: net.bridge.bridge-nf-call-iptables = 1
Dec 14 00:28:42 undercloud-0-trunk.localdomain neutron-enable-bridge-firewall.sh[22767]: net.bridge.bridge-nf-call-ip6tables = 1
Dec 14 00:28:42 undercloud-0-trunk.localdomain systemd[1]: Started OpenStack Neutron Open vSwitch Agent.


So this is definitely a new bug affecting Newton and Ocata.