diff --git a/devstack/plugin.sh b/devstack/plugin.sh
index 04cef2347..e7455ae70 100755
--- a/devstack/plugin.sh
+++ b/devstack/plugin.sh
@@ -38,12 +38,21 @@ function install_fwaas() {
     fi
 }
 
+function is_ovn_enabled {
+    [[ $Q_AGENT == "ovn" ]] && return 0
+    return 1
+}
+
 function configure_fwaas_v2() {
     # Add conf file
     cp $NEUTRON_FWAAS_DIR/etc/neutron_fwaas.conf.sample $NEUTRON_FWAAS_CONF
     neutron_server_config_add $NEUTRON_FWAAS_CONF
     inicomment $NEUTRON_FWAAS_CONF service_providers service_provider
-    iniadd $NEUTRON_FWAAS_CONF service_providers service_provider $NEUTRON_FWAAS_SERVICE_PROVIDERV2
+    if is_ovn_enabled; then
+        iniadd $NEUTRON_FWAAS_CONF service_providers service_provider $NEUTRON_FWAAS_SERVICE_PROVIDERV2_OVN
+    else
+        iniadd $NEUTRON_FWAAS_CONF service_providers service_provider $NEUTRON_FWAAS_SERVICE_PROVIDERV2
+    fi
 
     neutron_fwaas_configure_driver fwaas_v2
     if is_service_enabled q-l3; then
diff --git a/devstack/settings b/devstack/settings
index e3b3b58fa..90af2cac9 100644
--- a/devstack/settings
+++ b/devstack/settings
@@ -8,5 +8,6 @@ NEUTRON_FWAAS_CONF_FILE=neutron_fwaas.conf
 NEUTRON_FWAAS_CONF=$NEUTRON_CONF_DIR/$NEUTRON_FWAAS_CONF_FILE
 
 NEUTRON_FWAAS_SERVICE_PROVIDERV2=${NEUTRON_FWAAS_SERVICE_PROVIDERV2:-FIREWALL_V2:fwaas_db:neutron_fwaas.services.firewall.service_drivers.agents.agents.FirewallAgentDriver:default}
+NEUTRON_FWAAS_SERVICE_PROVIDERV2_OVN=${NEUTRON_FWAAS_SERVICE_PROVIDERV2:-FIREWALL_V2:fwaas_db:neutron_fwaas.services.firewall.service_drivers.ovn.firewall_l3_driver.OVNFwaasDriver:default}
 
 enable_service q-fwaas-v2
diff --git a/neutron_fwaas/services/firewall/service_drivers/ovn/__init__.py b/neutron_fwaas/services/firewall/service_drivers/ovn/__init__.py
new file mode 100644
index 000000000..e69de29bb
diff --git a/neutron_fwaas/services/firewall/service_drivers/ovn/acl.py b/neutron_fwaas/services/firewall/service_drivers/ovn/acl.py
new file mode 100644
index 000000000..9de721ea6
--- /dev/null
+++ b/neutron_fwaas/services/firewall/service_drivers/ovn/acl.py
@@ -0,0 +1,237 @@
+# Copyright 2022 EasyStack, 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.
+
+from neutron.common.ovn import utils as ovn_utils
+from neutron_lib import constants as const
+
+from neutron_fwaas.services.firewall.service_drivers.ovn import \
+    constants as ovn_const
+from neutron_fwaas.services.firewall.service_drivers.ovn import \
+    exceptions as ovn_fw_exc
+
+
+def acl_direction(direction, port_group=None):
+    if direction == const.INGRESS_DIRECTION:
+        portdir = 'inport'
+    else:
+        portdir = 'outport'
+    return '%s == @%s' % (portdir, port_group)
+
+
+def acl_ethertype(rule):
+    match = ''
+    ip_version = None
+    icmp = None
+    if rule['ip_version'] == const.IP_VERSION_4:
+        match = ' && ip4'
+        ip_version = 'ip4'
+        icmp = 'icmp4'
+    elif rule['ip_version'] == const.IP_VERSION_6:
+        match = ' && ip6'
+        ip_version = 'ip6'
+        icmp = 'icmp6'
+    return match, ip_version, icmp
+
+
+def acl_ip(rule, ip_version):
+    src_ip = rule.get('source_ip_address')
+    dst_ip = rule.get('destination_ip_address')
+    src = ' && %s.src == %s' % (ip_version, src_ip) if src_ip else ''
+    dst = ' && %s.dst == %s' % (ip_version, dst_ip) if dst_ip else ''
+    return src + dst
+
+
+def get_min_max_ports_from_range(port_range):
+    if not port_range:
+        return [None, None]
+    min_port, sep, max_port = port_range.partition(":")
+    if not max_port:
+        max_port = min_port
+    return [int(min_port), int(max_port)]
+
+
+def acl_protocol_ports(protocol, port_range, is_dst=True):
+    match = ''
+    min_port, max_port = get_min_max_ports_from_range(port_range)
+    dir = 'dst' if is_dst else 'src'
+    if protocol in ovn_const.TRANSPORT_PROTOCOLS:
+        if min_port is not None and min_port == max_port:
+            match += ' && %s.%s == %d' % (protocol, dir, min_port)
+        else:
+            if min_port is not None:
+                match += ' && %s.%s >= %d' % (protocol, dir, min_port)
+            if max_port is not None:
+                match += ' && %s.%s <= %d' % (protocol, dir, max_port)
+    return match
+
+
+def acl_protocol_and_ports(rule, icmp):
+    match = ''
+    protocol = rule.get('protocol')
+    if protocol is None:
+        return match
+    src_port = rule.get('source_port')
+    dst_port = rule.get('destination_port')
+    if protocol in ovn_const.TRANSPORT_PROTOCOLS:
+        match += ' && %s' % protocol
+        match += acl_protocol_ports(protocol, src_port, is_dst=False)
+        match += acl_protocol_ports(protocol, dst_port)
+    elif protocol in ovn_const.ICMP_PROTOCOLS:
+        protocol = icmp
+        match += ' && %s' % protocol
+    return match
+
+
+def acl_action_and_priority(rule, direction):
+    action = rule['action']
+    pos = rule.get('position', 0)
+    if action == 'deny' and rule.get(ovn_const.DEFAULT_RULE, False):
+        return (ovn_const.ACL_ACTION_DROP,
+                ovn_const.ACL_PRIORITY_DEFAULT)
+    if direction == const.INGRESS_DIRECTION:
+        priority = ovn_const.ACL_PRIORITY_INGRESS
+    else:
+        priority = ovn_const.ACL_PRIORITY_EGRESS
+    if action == 'allow':
+        return (ovn_const.ACL_ACTION_ALLOW_STATELESS,
+                priority - pos)
+    elif action == 'deny':
+        return (ovn_const.ACL_ACTION_DROP,
+                priority - pos)
+    elif action == 'reject':
+        return (ovn_const.ACL_ACTION_REJECT,
+                priority - pos)
+
+
+def acl_entry_for_port_group(port_group, rule, direction, match):
+    dir_map = {const.INGRESS_DIRECTION: 'from-lport',
+               const.EGRESS_DIRECTION: 'to-lport'}
+    action, priority = acl_action_and_priority(rule, direction)
+
+    acl = {"port_group": port_group,
+           "priority": priority,
+           "action": action,
+           "log": False,
+           "name": [],
+           "severity": [],
+           "direction": dir_map[direction],
+           "match": match,
+           ovn_const.OVN_FWR_EXT_ID_KEY: rule['id']}
+    return acl
+
+
+def get_rule_acl_for_port_group(port_group, rule, direction):
+    match = acl_direction(direction, port_group=port_group)
+    ip_match, ip_version, icmp = acl_ethertype(rule)
+    match += ip_match
+    match += acl_ip(rule, ip_version)
+    match += acl_protocol_and_ports(rule, icmp)
+    return acl_entry_for_port_group(port_group, rule, direction, match)
+
+
+def update_ports_for_pg(nb_idl, txn, pg_name, ports_add=None,
+                        ports_delete=None):
+    if ports_add is None:
+        ports_add = []
+    if ports_delete is None:
+        ports_delete = []
+    # Add ports to port_group
+    for port_id in ports_add:
+        txn.add(nb_idl.pg_add_ports(
+            pg_name, port_id))
+    for port_id in ports_delete:
+        txn.add(nb_idl.pg_del_ports(
+            pg_name, port_id, if_exists=True))
+
+
+def get_default_acls_for_pg(nb_idl, pg_name):
+    nb_acls = nb_idl.pg_acl_list(pg_name).execute(check_error=True)
+    default_acl_list = []
+    for nb_acl in nb_acls:
+        # Get acl whose external_ids has firewall_rule_id, then
+        # append it to list if its value equal to default_rule_id
+        ext_ids = getattr(nb_acl, 'external_ids', {})
+        if (ext_ids.get(ovn_const.OVN_FWR_EXT_ID_KEY) ==
+                ovn_const.DEFAULT_RULE_ID):
+            default_acl_list.append(nb_acl.uuid)
+    return default_acl_list
+
+
+def process_rule_for_pg(nb_idl, txn, pg_name, rule, direction,
+                        op=ovn_const.OP_ADD):
+    dir_map = {const.INGRESS_DIRECTION: 'from-lport',
+               const.EGRESS_DIRECTION: 'to-lport'}
+    supported_ops = [ovn_const.OP_ADD, ovn_const.OP_DEL,
+                     ovn_const.OP_MOD]
+    if op not in supported_ops:
+        raise ovn_fw_exc.OperatorNotSupported(
+            operator=op, valid_operators=supported_ops)
+
+    acl = get_rule_acl_for_port_group(
+        pg_name, rule, direction)
+
+    # Add acl
+    if op == ovn_const.OP_ADD:
+        txn.add(nb_idl.pg_acl_add(**acl, may_exist=True))
+    # Modify/Delete acl
+    else:
+        nb_acls = nb_idl.pg_acl_list(pg_name).execute(check_error=True)
+        for nb_acl in nb_acls:
+            # Get acl whose external_ids has firewall_rule_id,
+            # then change it if its value equal to rule's
+            ext_ids = getattr(nb_acl, 'external_ids', {})
+            if (ext_ids.get(ovn_const.OVN_FWR_EXT_ID_KEY) ==
+                    rule['id'] and dir_map[direction] == nb_acl.direction):
+                if op == ovn_const.OP_MOD:
+                    txn.add(nb_idl.db_set(
+                        'ACL', nb_acl.uuid,
+                        ('match', acl['match']),
+                        ('action', acl['action'])))
+                elif op == ovn_const.OP_DEL:
+                    txn.add(nb_idl.pg_acl_del(
+                        acl['port_group'],
+                        acl['direction'],
+                        nb_acl.priority,
+                        acl['match']))
+                break
+
+
+def create_pg_for_fwg(nb_idl, fwg_id):
+    pg_name = ovn_utils.ovn_port_group_name(fwg_id)
+    # Add port_group
+    with nb_idl.transaction(check_error=True) as txn:
+        ext_ids = {ovn_const.OVN_FWG_EXT_ID_KEY: fwg_id}
+        txn.add(nb_idl.pg_add(name=pg_name, acls=[],
+                              external_ids=ext_ids))
+
+
+def add_default_acls_for_pg(nb_idl, txn, pg_name):
+    # Traffic is default denied, ipv4 or ipv6 with two directions,
+    # so number of default acls is 4
+    default_rule_v4 = {'action': 'deny', 'ip_version': 4,
+                       'id': ovn_const.DEFAULT_RULE_ID,
+                       ovn_const.DEFAULT_RULE: True}
+    default_rule_v6 = {'action': 'deny', 'ip_version': 6,
+                       'id': ovn_const.DEFAULT_RULE_ID,
+                       ovn_const.DEFAULT_RULE: True}
+    for dir in [const.EGRESS_DIRECTION, const.INGRESS_DIRECTION]:
+        process_rule_for_pg(nb_idl, txn, pg_name,
+                            default_rule_v4,
+                            dir,
+                            op=ovn_const.OP_ADD)
+        process_rule_for_pg(nb_idl, txn, pg_name,
+                            default_rule_v6,
+                            dir,
+                            op=ovn_const.OP_ADD)
diff --git a/neutron_fwaas/services/firewall/service_drivers/ovn/constants.py b/neutron_fwaas/services/firewall/service_drivers/ovn/constants.py
new file mode 100644
index 000000000..606c54ee1
--- /dev/null
+++ b/neutron_fwaas/services/firewall/service_drivers/ovn/constants.py
@@ -0,0 +1,44 @@
+# Copyright 2022 EasyStack, 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.
+
+from neutron_lib import constants as const
+
+OVN_FWG_EXT_ID_KEY = 'neutron:firewall_group_id'
+OVN_FWR_EXT_ID_KEY = 'neutron:firewall_rule_id'
+ACL_ACTION_DROP = 'drop'
+ACL_ACTION_REJECT = 'reject'
+ACL_ACTION_ALLOW_STATELESS = 'allow-stateless'
+ACL_ACTION_ALLOW = 'allow'
+ACL_PRIORITY_INGRESS = 2000
+ACL_PRIORITY_EGRESS = 2000
+ACL_PRIORITY_DEFAULT = 1001
+OP_ADD = 'add'
+OP_DEL = 'del'
+OP_MOD = 'mod'
+DEFAULT_RULE = 'is_default'
+DEFAULT_RULE_ID = 'default_rule'
+
+# Drop acls of ipv4 or ipv6 with two directions, so number of
+# default acls is 4
+DEFAULT_ACL_NUM = 4
+
+# Group of transport protocols supported
+TRANSPORT_PROTOCOLS = (const.PROTO_NAME_TCP,
+                       const.PROTO_NAME_UDP,
+                       const.PROTO_NAME_SCTP)
+
+# Group of versions of the ICMP protocol supported
+ICMP_PROTOCOLS = (const.PROTO_NAME_ICMP,
+                  const.PROTO_NAME_IPV6_ICMP)
diff --git a/neutron_fwaas/services/firewall/service_drivers/ovn/exceptions.py b/neutron_fwaas/services/firewall/service_drivers/ovn/exceptions.py
new file mode 100644
index 000000000..517b1b004
--- /dev/null
+++ b/neutron_fwaas/services/firewall/service_drivers/ovn/exceptions.py
@@ -0,0 +1,33 @@
+# Copyright 2022 EasyStack, 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.
+
+from neutron._i18n import _
+from neutron_lib import exceptions as n_exc
+
+
+class MechanismDriverNotFound(n_exc.NotFound):
+    message = _("None of the supported mechanism drivers found: "
+                "%(mechanism_drivers)s. Check your configuration.")
+
+
+class ProtocolNotSupported(n_exc.NeutronException):
+    message = _('The protocol "%(protocol)s" is not supported. Valid '
+                'protocols are: %(valid_protocols)s; or protocol '
+                'numbers ranging from 0 to 255.')
+
+
+class OperatorNotSupported(n_exc.NeutronException):
+    message = _('The operator "%(operator)s" is not supported. Valid '
+                'operators are: %(valid_operators)s.')
diff --git a/neutron_fwaas/services/firewall/service_drivers/ovn/firewall_l3_driver.py b/neutron_fwaas/services/firewall/service_drivers/ovn/firewall_l3_driver.py
new file mode 100644
index 000000000..715bd86bd
--- /dev/null
+++ b/neutron_fwaas/services/firewall/service_drivers/ovn/firewall_l3_driver.py
@@ -0,0 +1,358 @@
+# Copyright 2022 EasyStack, 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.
+
+from neutron.common.ovn import utils as ovn_utils
+from neutron_lib import constants as const
+from oslo_log import log as logging
+
+from neutron_fwaas.services.firewall.service_drivers import driver_api
+from neutron_fwaas.services.firewall.service_drivers.ovn import \
+    acl as ovn_acl
+from neutron_fwaas.services.firewall.service_drivers.ovn import \
+    constants as ovn_const
+from neutron_fwaas.services.firewall.service_drivers.ovn import \
+    exceptions as ovn_fw_exc
+
+LOG = logging.getLogger(__name__)
+
+
+class OVNFwaasDriver(driver_api.FirewallDriverDB):
+    """OVN l3 acl driver to implement
+
+    Depends on ml2/ovn, use ovn_client to put acl rules to the lsp which
+    is a peer of the lrp.
+    """
+
+    def __init__(self, service_plugin):
+        super(OVNFwaasDriver, self).__init__(service_plugin)
+        self._mech = None
+
+    def is_supported_l2_port(self, port):
+        return False
+
+    def is_supported_l3_port(self, port):
+        return True
+
+    def start_rpc_listener(self):
+        return []
+
+    @property
+    def _nb_ovn(self):
+        return self._mech_driver.nb_ovn
+
+    @property
+    def _mech_driver(self):
+        if self._mech is None:
+            drivers = ('ovn', 'ovn-sync')
+            for driver in drivers:
+                try:
+                    self._mech = \
+                        self._core_plugin.mechanism_manager.mech_drivers[
+                            driver].obj
+                    break
+                except KeyError:
+                    pass
+            else:
+                raise ovn_fw_exc.MechanismDriverNotFound(
+                    mechanism_drivers=drivers)
+        return self._mech
+
+    def _init_firewall_group(self, txn, fwg_id):
+        """Add port_group for firewall_group
+
+        After create port_group for fwg, add default drop acls to it
+        """
+        pg_name = ovn_utils.ovn_port_group_name(fwg_id)
+        ovn_acl.create_pg_for_fwg(self._nb_ovn, fwg_id)
+        ovn_acl.add_default_acls_for_pg(self._nb_ovn, txn, pg_name)
+        LOG.info("Successfully created port_group for firewall_group: %s",
+                 fwg_id)
+
+    def _add_rules_for_firewall_group(self, context, txn, fwg_id,
+                                      rule_id=None):
+        """Add all rules belong to firewall_group
+        """
+        fwg_with_rules = \
+            self.firewall_db.make_firewall_group_dict_with_rules(
+                context, fwg_id)
+        egress_rule_list = fwg_with_rules['egress_rule_list']
+        ingress_rule_list = fwg_with_rules['ingress_rule_list']
+        pg_name = ovn_utils.ovn_port_group_name(fwg_id)
+        rule_map = {const.INGRESS_DIRECTION: ingress_rule_list,
+                    const.EGRESS_DIRECTION: egress_rule_list}
+        for dir, rule_list in rule_map.items():
+            position = 0
+            for rule in rule_list:
+                rule['position'] = position
+                position += 1
+                if not rule['enabled']:
+                    continue
+                if rule_id:
+                    # For specify rule id
+                    if rule_id == rule['id']:
+                        ovn_acl.process_rule_for_pg(self._nb_ovn, txn,
+                                                    pg_name, rule, dir,
+                                                    op=ovn_const.OP_ADD)
+                        LOG.info("Successfully enable rule %(rule)s to "
+                                 "firewall_group %(fwg)s",
+                                 {"rule": rule_id,
+                                  "fwg": fwg_id})
+                        break
+                else:
+                    ovn_acl.process_rule_for_pg(self._nb_ovn, txn, pg_name,
+                                                rule, dir,
+                                                op=ovn_const.OP_ADD)
+        LOG.info("Successfully added rules for firewall_group %s",
+                 fwg_id)
+
+    def _clear_rules_for_firewall_group(self, context, txn, fwg_id):
+        """Clear acls belong to firewall_group
+
+        Delete all rule acls but remain the default acls
+        """
+        pg_name = ovn_utils.ovn_port_group_name(fwg_id)
+        default_acls = ovn_acl.get_default_acls_for_pg(self._nb_ovn, pg_name)
+        if len(default_acls) == ovn_const.DEFAULT_ACL_NUM:
+            txn.add(self._nb_ovn.db_set(
+                'Port_Group', pg_name,
+                ('acls', default_acls)))
+        else:
+            ovn_acl.add_default_acls_for_pg(self._nb_ovn, txn, pg_name)
+        LOG.info("Successfully clear rules for firewall_group %s",
+                 fwg_id)
+
+    def _process_acls_by_policies_or_rule(self, context, policy_ids,
+                                          rule_info=None,
+                                          op=ovn_const.OP_ADD):
+        """Delete/Update/Add the acls by rule or policies
+        """
+        ing_fwg_list = []
+        eg_fwg_list = []
+        if not policy_ids:
+            return
+        for policy_id in policy_ids:
+            ing_fwg_ids, eg_fwg_ids = self.firewall_db.get_fwgs_with_policy(
+                context, policy_id)
+            ing_fwg_list += ing_fwg_ids
+            eg_fwg_list += eg_fwg_ids
+
+        if not rule_info and op == ovn_const.OP_ADD:
+            # Add acls
+            rule_info = {}
+            for fwg_id in list(set(ing_fwg_list + eg_fwg_list)):
+                pg_name = ovn_utils.ovn_port_group_name(fwg_id)
+                with self._nb_ovn.transaction(check_error=True) as txn:
+                    if self._nb_ovn.get_port_group(pg_name):
+                        self._clear_rules_for_firewall_group(context, txn,
+                                                             fwg_id)
+                    else:
+                        self._init_firewall_group(txn, fwg_id)
+                    self._add_rules_for_firewall_group(context, txn, fwg_id)
+        elif rule_info and op == ovn_const.OP_ADD:
+            # Process the rule when enabled
+            for fwg_id in list(set(ing_fwg_list + eg_fwg_list)):
+                pg_name = ovn_utils.ovn_port_group_name(fwg_id)
+                with self._nb_ovn.transaction(check_error=True) as txn:
+                    if self._nb_ovn.get_port_group(pg_name):
+                        self._add_rules_for_firewall_group(context, txn,
+                                                           fwg_id,
+                                                           rule_info['id'])
+        elif rule_info:
+            # Delete/Update acls
+            fwg_map = {const.INGRESS_DIRECTION: list(set(ing_fwg_list)),
+                       const.EGRESS_DIRECTION: list(set(eg_fwg_list))}
+            for dir, fwg_list in fwg_map.items():
+                for fwg_id in fwg_list:
+                    pg_name = ovn_utils.ovn_port_group_name(fwg_id)
+                    with self._nb_ovn.transaction(check_error=True) as txn:
+                        if not self._nb_ovn.get_port_group(pg_name):
+                            LOG.warning("Cannot find Port_Group with name: %s",
+                                        pg_name)
+                            continue
+                        ovn_acl.process_rule_for_pg(self._nb_ovn, txn,
+                                                    pg_name, rule_info,
+                                                    dir, op=op)
+        LOG.info("Successfully %(op)s acls by rule %(rule)s "
+                 "and policies %(p_ids)s",
+                 {"op": op,
+                  "rule": rule_info.get('id'),
+                  "p_ids": policy_ids})
+
+    def create_firewall_group_precommit(self, context, firewall_group):
+        if not firewall_group['ports']:
+            LOG.info("No ports bound to firewall_group: %s, "
+                     "set it to inactive", firewall_group['id'])
+            status = const.INACTIVE
+        else:
+            status = const.PENDING_CREATE
+        with self._nb_ovn.transaction(check_error=True) as txn:
+            self._init_firewall_group(txn, firewall_group['id'])
+        firewall_group['status'] = status
+
+    def create_firewall_group_postcommit(self, context, firewall_group):
+        pg_name = ovn_utils.ovn_port_group_name(firewall_group['id'])
+        try:
+            with self._nb_ovn.transaction(check_error=True) as txn:
+                if (firewall_group['ingress_firewall_policy_id'] or
+                        firewall_group['egress_firewall_policy_id']):
+                    # Add rule acls to port_group
+                    self._add_rules_for_firewall_group(context, txn,
+                                                       firewall_group['id'])
+
+                if firewall_group['ports']:
+                    # Add ports to port_group
+                    ovn_acl.update_ports_for_pg(self._nb_ovn,
+                                                txn, pg_name,
+                                                firewall_group['ports'])
+                    firewall_group['status'] = const.ACTIVE
+                    LOG.info("Successfully added ports for firewall_group %s",
+                             firewall_group['id'])
+        except Exception:
+            with self._nb_ovn.transaction(check_error=True) as txn:
+                if self._nb_ovn.get_port_group(pg_name):
+                    txn.add(self._nb_ovn.pg_del(name=pg_name, if_exists=True))
+            LOG.error("Failed to create_firewall_group_postcommit.")
+            raise
+        else:
+            self.firewall_db.update_firewall_group_status(
+                context, firewall_group['id'], firewall_group['status'])
+
+    def update_firewall_group_precommit(self, context, old_firewall_group,
+                                        new_firewall_group):
+        port_updated = (set(new_firewall_group['ports']) !=
+                        set(old_firewall_group['ports']))
+        policies_updated = (
+                new_firewall_group['ingress_firewall_policy_id'] !=
+                old_firewall_group['ingress_firewall_policy_id'] or
+                new_firewall_group['egress_firewall_policy_id'] !=
+                old_firewall_group['egress_firewall_policy_id']
+        )
+        if port_updated or policies_updated:
+            new_firewall_group['status'] = const.PENDING_UPDATE
+
+    def update_firewall_group_postcommit(self, context, old_firewall_group,
+                                         new_firewall_group):
+        if new_firewall_group['status'] != const.PENDING_UPDATE:
+            return
+        old_ports = set(old_firewall_group['ports'])
+        new_ports = set(new_firewall_group['ports'])
+        old_ing_policy = old_firewall_group['ingress_firewall_policy_id']
+        new_ing_policy = new_firewall_group['ingress_firewall_policy_id']
+        old_eg_policy = old_firewall_group['egress_firewall_policy_id']
+        new_eg_policy = new_firewall_group['egress_firewall_policy_id']
+        pg_name = ovn_utils.ovn_port_group_name(new_firewall_group['id'])
+
+        # We except it would be active
+        # If no ports, set it to inactive
+        new_firewall_group['status'] = const.ACTIVE
+        if not new_ports:
+            LOG.info("No ports bound to firewall_group: %s, "
+                     "set it to inactive", new_firewall_group['id'])
+            new_firewall_group['status'] = const.INACTIVE
+
+        # If port_group is not exist, recreate it,
+        # add acls and ports.
+        if not self._nb_ovn.get_port_group(pg_name):
+            with self._nb_ovn.transaction(check_error=True) as txn:
+                self._init_firewall_group(txn, new_firewall_group['id'])
+                if new_ports:
+                    ovn_acl.update_ports_for_pg(self._nb_ovn, txn,
+                                                pg_name, new_ports)
+                if new_ing_policy or new_eg_policy:
+                    self._add_rules_for_firewall_group(
+                        context, txn, new_firewall_group['id'])
+        else:
+            with self._nb_ovn.transaction(check_error=True) as txn:
+                # Process changes of ports
+                if old_ports != new_ports:
+                    ports_add = list(new_ports - old_ports)
+                    ports_delete = list(old_ports - new_ports)
+                    ovn_acl.update_ports_for_pg(self._nb_ovn, txn, pg_name,
+                                                ports_add, ports_delete)
+                # Process changes of policies
+                if (old_ing_policy != new_ing_policy or
+                        old_eg_policy != new_eg_policy):
+                    # Clear rules first
+                    self._clear_rules_for_firewall_group(
+                        context, txn, new_firewall_group['id'])
+                    # Add rules if it has
+                    if new_ing_policy or new_eg_policy:
+                        self._add_rules_for_firewall_group(
+                            context, txn, new_firewall_group['id'])
+
+        self.firewall_db.update_firewall_group_status(
+            context, new_firewall_group['id'],
+            new_firewall_group['status'])
+
+    def delete_firewall_group_precommit(self, context, firewall_group):
+        pg_name = ovn_utils.ovn_port_group_name(firewall_group['id'])
+        with self._nb_ovn.transaction(check_error=True) as txn:
+            if self._nb_ovn.get_port_group(pg_name):
+                txn.add(self._nb_ovn.pg_del(name=pg_name, if_exists=True))
+
+    def update_firewall_policy_postcommit(self, context, old_firewall_policy,
+                                          new_firewall_policy):
+        old_rules = old_firewall_policy['firewall_rules']
+        new_rules = new_firewall_policy['firewall_rules']
+        if old_rules == new_rules:
+            return
+        self._process_acls_by_policies_or_rule(context,
+                                               [new_firewall_policy['id']])
+
+    def update_firewall_rule_postcommit(self, context, old_firewall_rule,
+                                        new_firewall_rule):
+        NEED_UPDATE_FIELDS = ['enabled', 'protocol', 'ip_version',
+                              'source_ip_address', 'destination_ip_address',
+                              'source_port', 'destination_port', 'action']
+        need_update = False
+        for field in NEED_UPDATE_FIELDS:
+            if old_firewall_rule[field] != new_firewall_rule[field]:
+                need_update = True
+        if not need_update:
+            return
+        firewall_policy_ids = old_firewall_rule.get('firewall_policy_id')
+
+        # If rule is enabled, its acls should be inserted
+        # If rule is disabled, its acls should be removed
+        # If rule is always disabled, nothing to do
+        if not old_firewall_rule['enabled'] and new_firewall_rule['enabled']:
+            self._process_acls_by_policies_or_rule(context,
+                                                   firewall_policy_ids,
+                                                   new_firewall_rule)
+            return
+        elif old_firewall_rule['enabled'] and not new_firewall_rule['enabled']:
+            self._process_acls_by_policies_or_rule(context,
+                                                   firewall_policy_ids,
+                                                   old_firewall_rule,
+                                                   ovn_const.OP_DEL)
+            return
+        elif not new_firewall_rule['enabled']:
+            return
+
+        # Process changes of rule
+        self._process_acls_by_policies_or_rule(
+            context, firewall_policy_ids, new_firewall_rule, ovn_const.OP_MOD)
+        LOG.info("Successfully updated acls for rule: %s",
+                 new_firewall_rule['id'])
+
+    def insert_rule_postcommit(self, context, policy_id, rule_info):
+        # Add acls by policy_id
+        self._process_acls_by_policies_or_rule(context, [policy_id])
+
+    def remove_rule_postcommit(self, context, policy_id, rule_info):
+        rule_detail = self.firewall_db.get_firewall_rule(
+            context, rule_info['firewall_rule_id'])
+        self._process_acls_by_policies_or_rule(
+            context, [policy_id], rule_detail, ovn_const.OP_DEL)
diff --git a/neutron_fwaas/tests/unit/services/firewall/service_drivers/ovn/__init__.py b/neutron_fwaas/tests/unit/services/firewall/service_drivers/ovn/__init__.py
new file mode 100644
index 000000000..e69de29bb
diff --git a/neutron_fwaas/tests/unit/services/firewall/service_drivers/ovn/test_firewall_l3_driver.py b/neutron_fwaas/tests/unit/services/firewall/service_drivers/ovn/test_firewall_l3_driver.py
new file mode 100644
index 000000000..57d045c3c
--- /dev/null
+++ b/neutron_fwaas/tests/unit/services/firewall/service_drivers/ovn/test_firewall_l3_driver.py
@@ -0,0 +1,452 @@
+# Copyright 2022 EasyStack, 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.
+
+from unittest import mock
+
+from neutron import extensions as neutron_extensions
+from neutron.tests.unit.extensions import test_l3
+from neutron.tests.unit import fake_resources as fakes
+from neutron_lib import constants as nl_constants
+from neutron_lib import context
+
+from neutron_fwaas.services.firewall.service_drivers import driver_api
+from neutron_fwaas.services.firewall.service_drivers.ovn import \
+    firewall_l3_driver as ovn_driver
+from neutron_fwaas.tests.unit.services.firewall import test_fwaas_plugin_v2
+
+
+OVN_FWAAS_DRIVER = ('neutron_fwaas.services.firewall.service_drivers.'
+                    'ovn.firewall_l3_driver.OVNFwaasDriver')
+
+
+class TestOVNFwaasDriver(test_fwaas_plugin_v2.FirewallPluginV2TestCase,
+                         test_l3.L3NatTestCaseMixin):
+
+    def setUp(self):
+        l3_plugin_str = ('neutron.tests.unit.extensions.test_l3.'
+                         'TestL3NatServicePlugin')
+        l3_plugin = {'l3_plugin_name': l3_plugin_str}
+        super(TestOVNFwaasDriver, self).setUp(
+            service_provider=OVN_FWAAS_DRIVER,
+            extra_service_plugins=l3_plugin,
+            extra_extension_paths=neutron_extensions.__path__)
+        self.db = self.plugin.driver.firewall_db
+        self.mech_driver = mock.MagicMock()
+        self.nb_ovn = fakes.FakeOvsdbNbOvnIdl()
+        self.sb_ovn = fakes.FakeOvsdbSbOvnIdl()
+        self.mech_driver._nb_ovn = self.nb_ovn
+        self.mech_driver._sb_ovn = self.sb_ovn
+
+    @property
+    def _self_context(self):
+        return context.Context('', self._tenant_id)
+
+    def test_create_firewall_group_ports_not_specified(self):
+        with self.firewall_policy(as_admin=True) as fwp, \
+            mock.patch.object(driver_api.FirewallDriver,
+                              '_core_plugin') as mock_ml2:
+            fwp_id = fwp['firewall_policy']['id']
+            mock_ml2.mechanism_manager = mock.MagicMock()
+            mock_ml2.mechanism_manager.mech_drivers = {
+                'ovn': self.mech_driver}
+            with self.firewall_group(
+                    name='test',
+                    ingress_firewall_policy_id=fwp_id,
+                    egress_firewall_policy_id=fwp_id,
+                    admin_state_up=True,
+                    as_admin=True) as fwg1:
+                self.assertEqual(nl_constants.INACTIVE,
+                    fwg1['firewall_group']['status'])
+
+    def test_create_firewall_group_with_ports(self):
+        with self.router(name='router1', admin_state_up=True,
+            tenant_id=self._tenant_id, as_admin=True) as r, \
+                self.subnet(as_admin=True) as s1, \
+                self.subnet(cidr='20.0.0.0/24', as_admin=True) as s2:
+            body = self._router_interface_action(
+                'add',
+                r['router']['id'],
+                s1['subnet']['id'],
+                None,
+                as_admin=True)
+            port_id1 = body['port_id']
+
+            body = self._router_interface_action(
+                'add',
+                r['router']['id'],
+                s2['subnet']['id'],
+                None,
+                as_admin=True)
+            port_id2 = body['port_id']
+            fwg_ports = [port_id1, port_id2]
+            with self.firewall_policy(do_delete=False,
+                                      as_admin=True) as fwp, \
+                mock.patch.object(ovn_driver.OVNFwaasDriver,
+                                  '_nb_ovn') as mock_nb_ovn:
+                fwp_id = fwp['firewall_policy']['id']
+                mock_nb_ovn.return_value = self.nb_ovn
+                with self.firewall_group(
+                        name='test',
+                        ingress_firewall_policy_id=fwp_id,
+                        egress_firewall_policy_id=fwp_id,
+                        ports=fwg_ports, admin_state_up=True,
+                        do_delete=False, as_admin=True) as fwg1:
+                    self.assertEqual(nl_constants.ACTIVE,
+                                     fwg1['firewall_group']['status'])
+
+    def test_update_firewall_group_with_new_ports(self):
+        with self.router(name='router1', admin_state_up=True,
+            tenant_id=self._tenant_id, as_admin=True) as r, \
+                self.subnet(as_admin=True) as s1, \
+                self.subnet(cidr='20.0.0.0/24', as_admin=True) as s2, \
+                self.subnet(cidr='30.0.0.0/24', as_admin=True) as s3:
+            body = self._router_interface_action(
+                'add',
+                r['router']['id'],
+                s1['subnet']['id'],
+                None,
+                as_admin=True)
+            port_id1 = body['port_id']
+
+            body = self._router_interface_action(
+                'add',
+                r['router']['id'],
+                s2['subnet']['id'],
+                None,
+                as_admin=True)
+            port_id2 = body['port_id']
+
+            body = self._router_interface_action(
+                'add',
+                r['router']['id'],
+                s3['subnet']['id'],
+                None,
+                as_admin=True)
+            port_id3 = body['port_id']
+            fwg_ports = [port_id1, port_id2]
+            with self.firewall_policy(do_delete=False,
+                                      as_admin=True) as fwp, \
+                mock.patch.object(ovn_driver.OVNFwaasDriver,
+                                  '_nb_ovn') as mock_nb_ovn:
+                fwp_id = fwp['firewall_policy']['id']
+                mock_nb_ovn.return_value = self.nb_ovn
+                with self.firewall_group(
+                        name='test',
+                        ingress_firewall_policy_id=fwp_id,
+                        egress_firewall_policy_id=fwp_id,
+                        ports=fwg_ports, admin_state_up=True,
+                        do_delete=False, as_admin=True) as fwg1:
+                    self.assertEqual(nl_constants.ACTIVE,
+                         fwg1['firewall_group']['status'])
+                    data = {'firewall_group': {'ports': [port_id2, port_id3]}}
+                    req = self.new_update_request('firewall_groups', data,
+                                                  fwg1['firewall_group']['id'],
+                                                  context=self._self_context,
+                                                  as_admin=True)
+                    res = self.deserialize(self.fmt,
+                                           req.get_response(self.ext_api))
+
+                    self.assertEqual(sorted([port_id2, port_id3]),
+                                     sorted(res['firewall_group']['ports']))
+
+                    self.assertEqual(nl_constants.ACTIVE,
+                                     res['firewall_group']['status'])
+
+    def test_update_firewall_group_with_ports_and_policy(self):
+        with self.router(name='router1', admin_state_up=True,
+                         tenant_id=self._tenant_id, as_admin=True) as r, \
+                self.subnet(as_admin=True) as s1, \
+                self.subnet(cidr='20.0.0.0/24', as_admin=True) as s2:
+            body = self._router_interface_action(
+                'add',
+                r['router']['id'],
+                s1['subnet']['id'],
+                None,
+                as_admin=True)
+            port_id1 = body['port_id']
+
+            body = self._router_interface_action(
+                'add',
+                r['router']['id'],
+                s2['subnet']['id'],
+                None,
+                as_admin=True)
+            port_id2 = body['port_id']
+
+            fwg_ports = [port_id1, port_id2]
+            with self.firewall_rule(do_delete=False, as_admin=True) as fwr, \
+                mock.patch.object(ovn_driver.OVNFwaasDriver,
+                                  '_nb_ovn') as mock_nb_ovn:
+                mock_nb_ovn.return_value = self.nb_ovn
+                with self.firewall_policy(
+                        firewall_rules=[fwr['firewall_rule']['id']],
+                        do_delete=False,
+                        as_admin=True) as fwp:
+                    with self.firewall_group(
+                            name='test',
+                            default_policy=False,
+                            ports=fwg_ports,
+                            admin_state_up=True,
+                            do_delete=False,
+                            as_admin=True) as fwg1:
+                        self.assertEqual(nl_constants.ACTIVE,
+                             fwg1['firewall_group']['status'])
+
+                        fwp_id = fwp["firewall_policy"]["id"]
+                        data = {'firewall_group': {'ports': fwg_ports}}
+                        req = (self.
+                               new_update_request('firewall_groups', data,
+                                                  fwg1['firewall_group']['id'],
+                                                  context=self._self_context,
+                                                  as_admin=True))
+                        res = self.deserialize(self.fmt,
+                                               req.get_response(self.ext_api))
+                        self.assertEqual(nl_constants.ACTIVE,
+                                         res['firewall_group']['status'])
+
+                        data = {'firewall_group': {
+                            'ingress_firewall_policy_id': fwp_id}}
+                        req = (self.
+                               new_update_request('firewall_groups', data,
+                                                  fwg1['firewall_group']['id'],
+                                                  context=self._self_context,
+                                                  as_admin=True))
+                        res = self.deserialize(self.fmt,
+                                               req.get_response(self.ext_api))
+                        self.assertEqual(nl_constants.ACTIVE,
+                                         res['firewall_group']['status'])
+
+    def test_update_firewall_policy_with_new_rules(self):
+        with self.firewall_rule(do_delete=False, as_admin=True) as fwr, \
+            self.firewall_rule(name='firewall_rule2', action='reject',
+                               do_delete=False, as_admin=True) as fwr2, \
+            self.firewall_rule(name='firewall_rule3', action='deny',
+                               do_delete=False, as_admin=True) as fwr3, \
+            mock.patch.object(ovn_driver.OVNFwaasDriver,
+                              '_nb_ovn') as mock_nb_ovn:
+            mock_nb_ovn.return_value = self.nb_ovn
+            fwr_id = fwr['firewall_rule']['id']
+            fwr2_id = fwr2['firewall_rule']['id']
+            fwr3_id = fwr3['firewall_rule']['id']
+            with self.firewall_policy(
+                    firewall_rules=[fwr_id],
+                    do_delete=False,
+                    as_admin=True) as fwp:
+                fwp_id = fwp['firewall_policy']['id']
+                with self.firewall_group(
+                        name='test',
+                        default_policy=False,
+                        admin_state_up=True,
+                        ingress_firewall_policy_id=fwp_id,
+                        egress_firewall_policy_id=fwp_id,
+                        do_delete=False,
+                        as_admin=True) as fwg1:
+                    self.assertEqual(nl_constants.INACTIVE,
+                         fwg1['firewall_group']['status'])
+
+                    new_rules = [fwr_id, fwr2_id, fwr3_id]
+                    data = {'firewall_policy': {'firewall_rules':
+                                                new_rules}}
+                    req = (self.
+                           new_update_request('firewall_policies', data,
+                                              fwp_id,
+                                              context=self._self_context,
+                                              as_admin=True))
+                    res = self.deserialize(self.fmt,
+                                           req.get_response(self.ext_api))
+
+                    self.assertEqual(new_rules,
+                                     res['firewall_policy']['firewall_rules'])
+
+    def test_disable_firewall_rule(self):
+        with self.firewall_rule(do_delete=False, as_admin=True) as fwr, \
+            mock.patch.object(ovn_driver.OVNFwaasDriver,
+                              '_nb_ovn') as mock_nb_ovn:
+            mock_nb_ovn.return_value = self.nb_ovn
+            fwr_id = fwr['firewall_rule']['id']
+            with self.firewall_policy(
+                    firewall_rules=[fwr_id],
+                    do_delete=False,
+                    as_admin=True) as fwp:
+                fwp_id = fwp['firewall_policy']['id']
+                with self.firewall_group(
+                        name='test',
+                        default_policy=False,
+                        admin_state_up=True,
+                        ingress_firewall_policy_id=fwp_id,
+                        egress_firewall_policy_id=fwp_id,
+                        do_delete=False,
+                        as_admin=True) as fwg1:
+                    self.assertEqual(nl_constants.INACTIVE,
+                         fwg1['firewall_group']['status'])
+
+                    data = {'firewall_rule': {'enabled': False}}
+                    req = (self.
+                           new_update_request('firewall_rules', data,
+                                              fwr_id,
+                                              context=self._self_context,
+                                              as_admin=True))
+                    res = self.deserialize(self.fmt,
+                                           req.get_response(self.ext_api))
+
+                    self.assertEqual(False,
+                                     res['firewall_rule']['enabled'])
+
+    def test_enable_firewall_rule(self):
+        with self.firewall_rule(enabled=False, do_delete=False,
+                                as_admin=True) as fwr, \
+            mock.patch.object(ovn_driver.OVNFwaasDriver,
+                              '_nb_ovn') as mock_nb_ovn:
+            mock_nb_ovn.return_value = self.nb_ovn
+            fwr_id = fwr['firewall_rule']['id']
+            with self.firewall_policy(
+                    firewall_rules=[fwr_id],
+                    do_delete=False,
+                    as_admin=True) as fwp:
+                fwp_id = fwp['firewall_policy']['id']
+                with self.firewall_group(
+                        name='test',
+                        default_policy=False,
+                        admin_state_up=True,
+                        ingress_firewall_policy_id=fwp_id,
+                        egress_firewall_policy_id=fwp_id,
+                        do_delete=False,
+                        as_admin=True) as fwg1:
+                    self.assertEqual(nl_constants.INACTIVE,
+                         fwg1['firewall_group']['status'])
+
+                    data = {'firewall_rule': {'enabled': True}}
+                    req = (self.
+                           new_update_request('firewall_rules', data,
+                                              fwr_id,
+                                              context=self._self_context,
+                                              as_admin=True))
+                    res = self.deserialize(self.fmt,
+                                           req.get_response(self.ext_api))
+
+                    self.assertEqual(True,
+                                     res['firewall_rule']['enabled'])
+
+    def test_update_firewall_rule_with_action(self):
+        with self.firewall_rule(source_port=None, destination_port=None,
+                                protocol='icmp', do_delete=False,
+                                as_admin=True) as fwr, \
+            mock.patch.object(ovn_driver.OVNFwaasDriver,
+                              '_nb_ovn') as mock_nb_ovn:
+            mock_nb_ovn.return_value = self.nb_ovn
+            fwr_id = fwr['firewall_rule']['id']
+            with self.firewall_policy(
+                    firewall_rules=[fwr_id],
+                    do_delete=False,
+                    as_admin=True) as fwp:
+                fwp_id = fwp['firewall_policy']['id']
+                with self.firewall_group(
+                        name='test',
+                        default_policy=False,
+                        admin_state_up=True,
+                        ingress_firewall_policy_id=fwp_id,
+                        egress_firewall_policy_id=fwp_id,
+                        do_delete=False,
+                        as_admin=True) as fwg1:
+                    self.assertEqual(nl_constants.INACTIVE,
+                         fwg1['firewall_group']['status'])
+
+                    data = {'firewall_rule': {'action': 'deny'}}
+                    req = (self.
+                           new_update_request('firewall_rules', data,
+                                              fwr_id,
+                                              context=self._self_context,
+                                              as_admin=True))
+                    res = self.deserialize(self.fmt,
+                                           req.get_response(self.ext_api))
+
+                    self.assertEqual('deny',
+                                     res['firewall_rule']['action'])
+
+    def test_insert_rule_into_firewall_policy(self):
+        with self.firewall_rule(do_delete=False, as_admin=True) as fwr, \
+            self.firewall_rule(name='firewall_rule2', action='reject',
+                               do_delete=False, as_admin=True) as fwr2, \
+            mock.patch.object(ovn_driver.OVNFwaasDriver,
+                              '_nb_ovn') as mock_nb_ovn:
+            mock_nb_ovn.return_value = self.nb_ovn
+            fwr_id = fwr['firewall_rule']['id']
+            fwr2_id = fwr2['firewall_rule']['id']
+            with self.firewall_policy(
+                    firewall_rules=[fwr_id],
+                    do_delete=False,
+                    as_admin=True) as fwp:
+                fwp_id = fwp['firewall_policy']['id']
+                with self.firewall_group(
+                        name='test',
+                        default_policy=False,
+                        admin_state_up=True,
+                        ingress_firewall_policy_id=fwp_id,
+                        egress_firewall_policy_id=fwp_id,
+                        do_delete=False,
+                        as_admin=True) as fwg1:
+                    self.assertEqual(nl_constants.INACTIVE,
+                         fwg1['firewall_group']['status'])
+
+                    data = {'firewall_rule_id': fwr2_id,
+                            'insert_after': fwr_id}
+                    req = (self.
+                           new_update_request('firewall_policies', data,
+                                              fwp_id,
+                                              subresource='insert_rule',
+                                              context=self._self_context,
+                                              as_admin=True))
+                    res = self.deserialize(self.fmt,
+                                           req.get_response(self.ext_api))
+
+                    self.assertEqual([fwr_id, fwr2_id],
+                                     res['firewall_rules'])
+
+    def test_remove_rules_from_firewall_policy(self):
+        with self.firewall_rule(do_delete=False, as_admin=True) as fwr, \
+            self.firewall_rule(name='firewall_rule2', action='reject',
+                               do_delete=False, as_admin=True) as fwr2, \
+            mock.patch.object(ovn_driver.OVNFwaasDriver,
+                              '_nb_ovn') as mock_nb_ovn:
+            mock_nb_ovn.return_value = self.nb_ovn
+            fwr_id = fwr['firewall_rule']['id']
+            fwr2_id = fwr2['firewall_rule']['id']
+            with self.firewall_policy(
+                    firewall_rules=[fwr_id, fwr2_id],
+                    do_delete=False, as_admin=True) as fwp:
+                fwp_id = fwp['firewall_policy']['id']
+                with self.firewall_group(
+                        name='test',
+                        default_policy=False,
+                        admin_state_up=True,
+                        ingress_firewall_policy_id=fwp_id,
+                        egress_firewall_policy_id=fwp_id,
+                        do_delete=False,
+                        as_admin=True) as fwg1:
+                    self.assertEqual(nl_constants.INACTIVE,
+                         fwg1['firewall_group']['status'])
+
+                    data = {'firewall_rule_id': fwr2_id}
+                    req = (self.
+                           new_update_request('firewall_policies', data,
+                                              fwp_id,
+                                              subresource='remove_rule',
+                                              context=self._self_context,
+                                              as_admin=True))
+                    res = self.deserialize(self.fmt,
+                                           req.get_response(self.ext_api))
+
+                    self.assertEqual([fwr_id],
+                                     res['firewall_rules'])
diff --git a/releasenotes/notes/support-l3-firewall-for-ovn-driver-3f5632ad13cf35fd.yaml b/releasenotes/notes/support-l3-firewall-for-ovn-driver-3f5632ad13cf35fd.yaml
new file mode 100644
index 000000000..442252e3b
--- /dev/null
+++ b/releasenotes/notes/support-l3-firewall-for-ovn-driver-3f5632ad13cf35fd.yaml
@@ -0,0 +1,15 @@
+---
+features:
+  - L3 stateless firewall support for ML2/OVN driver is implemented.
+issues:
+  - |
+    If the user configures stateful security group rules for VMs ports and
+    stateless L3 firewall rules for gateway ports like this:
+
+        - SG ingress rules: --remote_ip_prefix 0.0.0.0/0
+        - FW ingress rules: --destination_ip_address 0.0.0.0/0 --action allow
+
+    It only opens ingress traffic for another network to access VM, but the
+    reply traffic (egress direction) also passes because it matches the
+    committed conntrack entry.
+    So it only works well with stateless security groups for VMs.