diff --git a/neutron/cmd/ovn/__init__.py b/neutron/cmd/ovn/__init__.py
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/neutron/cmd/ovn/migration_mtu.py b/neutron/cmd/ovn/migration_mtu.py
new file mode 100644
index 00000000000..a5bd9d77960
--- /dev/null
+++ b/neutron/cmd/ovn/migration_mtu.py
@@ -0,0 +1,119 @@
+# Copyright 2018 Red Hat, Inc.
+# All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+import os
+import sys
+
+from openstack import connection
+
+# TODO(dalvarez): support also GRE
+GENEVE_TO_VXLAN_OVERHEAD = 8
+
+
+def get_connection():
+    user_domain_id = os.environ.get('OS_USER_DOMAIN_ID', 'default')
+    project_domain_id = os.environ.get('OS_PROJECT_DOMAIN_ID', 'default')
+    conn = connection.Connection(auth_url=os.environ['OS_AUTH_URL'],
+                                 project_name=os.environ['OS_PROJECT_NAME'],
+                                 username=os.environ['OS_USERNAME'],
+                                 password=os.environ['OS_PASSWORD'],
+                                 user_domain_id=user_domain_id,
+                                 project_domain_id=project_domain_id)
+    return conn
+
+
+def verify_network_mtu():
+    print("Verifying the tenant network mtu's")
+    conn = get_connection()
+    success = True
+    for network in conn.network.networks():
+        if network.provider_physical_network is None and (
+            network.provider_network_type == 'vxlan') and (
+                'adapted_mtu' not in network.tags):
+            print("adapted_mtu tag is not set for the Network "
+                  "[" + str(network.name) + "]")
+            success = False
+
+    if success:
+        print("All the networks are set to expected mtu value")
+    else:
+        print("Some tenant networks need to have their MTU updated to a "
+              "lower value.")
+    return success
+
+
+def update_network_mtu():
+    print("Updating the tenant network mtu")
+    conn = get_connection()
+    for network in conn.network.networks():
+        try:
+            if network.provider_physical_network is None and (
+                    network.provider_network_type == 'vxlan') and (
+                        'adapted_mtu' not in network.tags):
+                print("Updating the mtu and the tag 'adapted_mtu"
+                      " of the network - " + str(network.name))
+                new_tags = list(network.tags)
+                new_tags.append('adapted_mtu')
+                conn.network.update_network(
+                    network,
+                    mtu=int(network.mtu) - GENEVE_TO_VXLAN_OVERHEAD)
+                conn.network.set_tags(network, new_tags)
+        except Exception as e:
+            print("Exception occured while updating the MTU:" + str(e))
+            return False
+    return True
+
+
+def print_usage():
+    print('Invalid options:')
+    print('Usage: %s <update|verify> mtu' % sys.argv[0])
+
+
+def main():
+    """Tool for updating the networks MTU's pre migration.
+
+    This lowers the MTU of the pre migration VXLAN and GRE networks. The
+    tool will ignore non-VXLAN/GRE networks, so if you use VLAN for tenant
+    networks it will be fine if you find this step not doing anything.
+
+    This step will go network by network reducing the MTU, and tagging
+    with adapted_mtu the networks which have been already handled.
+
+    Every time a network is updated all the existing L3/DHCP agents
+    connected to such network will update their internal leg MTU,
+    instances will start fetching the new MTU as the DHCP T1 timer
+    expires. As explained before, instances not obeying the DHCP T1
+    parameter will need to be restarted, and instances with static IP
+    assignment will need to be manually updated.
+    """
+    if len(sys.argv) < 3:
+        print_usage()
+        sys.exit(1)
+
+    retval = 1
+    if sys.argv[1] == "update" and sys.argv[2] == "mtu":
+        if update_network_mtu():
+            retval = 0
+    elif sys.argv[1] == "verify" and sys.argv[2] == "mtu":
+        if verify_network_mtu():
+            retval = 0
+    else:
+        print_usage()
+
+    sys.exit(retval)
+
+
+if __name__ == "__main__":
+    main()
diff --git a/neutron/cmd/ovn/neutron_ovn_db_sync_util.py b/neutron/cmd/ovn/neutron_ovn_db_sync_util.py
new file mode 100644
index 00000000000..d0620497e2a
--- /dev/null
+++ b/neutron/cmd/ovn/neutron_ovn_db_sync_util.py
@@ -0,0 +1,222 @@
+# Copyright 2016 Red Hat, Inc.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+import copy
+
+from neutron_lib.agent import topics
+from neutron_lib.plugins import directory
+from oslo_config import cfg
+from oslo_db import options as db_options
+from oslo_log import log as logging
+
+from neutron.conf.agent import securitygroups_rpc
+from neutron.conf.plugins.ml2.drivers.ovn import ovn_conf
+from neutron import manager
+from neutron import opts as neutron_options
+from neutron.plugins.ml2.drivers.ovn.mech_driver import mech_driver
+from neutron.plugins.ml2.drivers.ovn.mech_driver.ovsdb import impl_idl_ovn
+from neutron.plugins.ml2.drivers.ovn.mech_driver.ovsdb import ovn_client
+from neutron.plugins.ml2.drivers.ovn.mech_driver.ovsdb import ovn_db_sync
+from neutron.plugins.ml2 import plugin as ml2_plugin
+
+LOG = logging.getLogger(__name__)
+
+
+class Ml2Plugin(ml2_plugin.Ml2Plugin):
+
+    def _setup_dhcp(self):
+        pass
+
+    def _start_rpc_notifiers(self):
+        # Override the notifier so that when calling the ML2 plugin to create
+        # resources, it doesn't crash trying to notify subscribers.
+        self.notifier = AgentNotifierApi(topics.AGENT)
+
+
+class OVNMechanismDriver(mech_driver.OVNMechanismDriver):
+
+    def subscribe(self):
+        pass
+
+    def post_fork_initialize(self, resource, event, trigger, **kwargs):
+        pass
+
+    @property
+    def ovn_client(self):
+        if not self._ovn_client:
+            self._ovn_client = ovn_client.OVNClient(self._nb_ovn, self._sb_ovn)
+        return self._ovn_client
+
+    # Since we are not using the ovn mechanism driver while syncing,
+    # we override the post and pre commit methods so that original ones are
+    # not called.
+    def create_port_precommit(self, context):
+        pass
+
+    def create_port_postcommit(self, context):
+        port = context.current
+        self.ovn_client.create_port(port)
+
+    def update_port_precommit(self, context):
+        pass
+
+    def update_port_postcommit(self, context):
+        port = context.current
+        original_port = context.original
+        self.ovn_client.update_port(port, original_port)
+
+    def delete_port_precommit(self, context):
+        pass
+
+    def delete_port_postcommit(self, context):
+        port = copy.deepcopy(context.current)
+        port['network'] = context.network.current
+        # FIXME(lucasagomes): PortContext does not have a session, therefore
+        # we need to use the _plugin_context attribute.
+        self.ovn_client.delete_port(context._plugin_context, port['id'],
+                                    port_object=port)
+
+
+class AgentNotifierApi(object):
+    """Default Agent Notifier class for ovn-db-sync-util.
+
+    This class implements empty methods so that when creating resources in
+    the core plugin, the original ones don't get called and don't interfere
+    with the syncing process.
+    """
+    def __init__(self, topic):
+        self.topic = topic
+        self.topic_network_delete = topics.get_topic_name(topic,
+                                                          topics.NETWORK,
+                                                          topics.DELETE)
+        self.topic_port_update = topics.get_topic_name(topic,
+                                                       topics.PORT,
+                                                       topics.UPDATE)
+        self.topic_port_delete = topics.get_topic_name(topic,
+                                                       topics.PORT,
+                                                       topics.DELETE)
+        self.topic_network_update = topics.get_topic_name(topic,
+                                                          topics.NETWORK,
+                                                          topics.UPDATE)
+
+    def network_delete(self, context, network_id):
+        pass
+
+    def port_update(self, context, port, network_type, segmentation_id,
+                    physical_network):
+        pass
+
+    def port_delete(self, context, port_id):
+        pass
+
+    def network_update(self, context, network):
+        pass
+
+    def security_groups_provider_updated(self, context,
+                                         devices_to_udpate=None):
+        pass
+
+
+def setup_conf():
+    conf = cfg.CONF
+    ml2_group, ml2_opts = neutron_options.list_ml2_conf_opts()[0]
+    cfg.CONF.register_cli_opts(ml2_opts, ml2_group)
+    cfg.CONF.register_cli_opts(securitygroups_rpc.security_group_opts,
+                               'SECURITYGROUP')
+    ovn_group, ovn_opts = ovn_conf.list_opts()[0]
+    cfg.CONF.register_cli_opts(ovn_opts, group=ovn_group)
+    db_group, neutron_db_opts = db_options.list_opts()[0]
+    cfg.CONF.register_cli_opts(neutron_db_opts, db_group)
+    return conf
+
+
+def main():
+    """Main method for syncing neutron networks and ports with ovn nb db.
+
+    This script provides a utility for syncing the OVN Northbound Database
+    with the Neutron database.
+
+    This script is used for the migration from ML2/OVS to ML2/OVN.
+    """
+    conf = setup_conf()
+
+    # if no config file is passed or no configuration options are passed
+    # then load configuration from /etc/neutron/neutron.conf
+    try:
+        conf(project='neutron')
+    except TypeError:
+        LOG.error('Error parsing the configuration values. Please verify.')
+        return
+
+    logging.setup(conf, 'neutron_ovn_db_sync_util')
+    LOG.info('Started Neutron OVN db sync')
+    mode = ovn_conf.get_ovn_neutron_sync_mode()
+    if mode not in [ovn_db_sync.SYNC_MODE_LOG, ovn_db_sync.SYNC_MODE_REPAIR]:
+        LOG.error(
+            'Invalid sync mode : ["%s"]. Should be "log" or "repair"', mode)
+        return
+
+    # Validate and modify core plugin and ML2 mechanism drivers for syncing.
+    if (cfg.CONF.core_plugin.endswith('.Ml2Plugin') or
+            cfg.CONF.core_plugin == 'ml2'):
+        cfg.CONF.core_plugin = (
+            'neutron.cmd.ovn.neutron_ovn_db_sync_util.Ml2Plugin')
+        if not cfg.CONF.ml2.mechanism_drivers:
+            LOG.error('please use --config-file to specify '
+                      'neutron and ml2 configuration file.')
+            return
+        if 'ovn' not in cfg.CONF.ml2.mechanism_drivers:
+            LOG.error('No "ovn" mechanism driver found : "%s".',
+                      cfg.CONF.ml2.mechanism_drivers)
+            return
+        cfg.CONF.set_override('mechanism_drivers', ['ovn-sync'], 'ml2')
+        conf.service_plugins = [
+            'neutron.services.ovn_l3.plugin.OVNL3RouterPlugin']
+    else:
+        LOG.error('Invalid core plugin : ["%s"].', cfg.CONF.core_plugin)
+        return
+
+    try:
+        conn = impl_idl_ovn.get_connection(impl_idl_ovn.OvsdbNbOvnIdl)
+        ovn_api = impl_idl_ovn.OvsdbNbOvnIdl(conn)
+    except RuntimeError:
+        LOG.error('Invalid --ovn-ovn_nb_connection parameter provided.')
+        return
+
+    try:
+        sb_conn = impl_idl_ovn.get_connection(impl_idl_ovn.OvsdbSbOvnIdl)
+        ovn_sb_api = impl_idl_ovn.OvsdbSbOvnIdl(sb_conn)
+    except RuntimeError:
+        LOG.error('Invalid --ovn-ovn_sb_connection parameter provided.')
+        return
+
+    manager.init()
+    core_plugin = directory.get_plugin()
+    ovn_driver = core_plugin.mechanism_manager.mech_drivers['ovn-sync'].obj
+    ovn_driver._nb_ovn = ovn_api
+    ovn_driver._sb_ovn = ovn_sb_api
+
+    synchronizer = ovn_db_sync.OvnNbSynchronizer(
+        core_plugin, ovn_api, ovn_sb_api, mode, ovn_driver)
+
+    LOG.info('Sync for Northbound db started with mode : %s', mode)
+    synchronizer.do_sync()
+    LOG.info('Sync completed for Northbound db')
+
+    sb_synchronizer = ovn_db_sync.OvnSbSynchronizer(
+        core_plugin, ovn_sb_api, ovn_driver)
+
+    LOG.info('Sync for Southbound db started with mode : %s', mode)
+    sb_synchronizer.do_sync()
+    LOG.info('Sync completed for Southbound db')
diff --git a/setup.cfg b/setup.cfg
index ae2a7e5fdb8..457eec936b9 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -55,6 +55,8 @@ console_scripts =
     neutron-sanity-check = neutron.cmd.sanity_check:main
     neutron-status = neutron.cmd.status:main
     neutron-ovn-metadata-agent = neutron.cmd.eventlet.agents.ovn_metadata:main
+    neutron-ovn-migration-mtu = neutron.cmd.ovn.migration_mtu:main
+    neutron-ovn-db-sync-util = neutron.cmd.ovn.neutron_ovn_db_sync_util:main
 neutron.core_plugins =
     ml2 = neutron.plugins.ml2.plugin:Ml2Plugin
 neutron.service_plugins =
@@ -94,6 +96,7 @@ neutron.ml2.mechanism_drivers =
     l2population = neutron.plugins.ml2.drivers.l2pop.mech_driver:L2populationMechanismDriver
     sriovnicswitch = neutron.plugins.ml2.drivers.mech_sriov.mech_driver.mech_driver:SriovNicSwitchMechanismDriver
     ovn = neutron.plugins.ml2.drivers.ovn.mech_driver.mech_driver:OVNMechanismDriver
+    ovn-sync = neutron.cmd.ovn.neutron_ovn_db_sync_util:OVNMechanismDriver
     fake_agent = neutron.tests.unit.plugins.ml2.drivers.mech_fake_agent:FakeAgentMechanismDriver
     fake_agent_l3 = neutron.tests.unit.plugins.ml2.drivers.mech_fake_agent:FakeAgentMechanismDriverL3
     another_fake_agent = neutron.tests.unit.plugins.ml2.drivers.mech_fake_agent:AnotherFakeAgentMechanismDriver