diff --git a/neutron/services/metering/drivers/iptables/iptables_driver.py b/neutron/services/metering/drivers/iptables/iptables_driver.py
index 5c2c080f094..b6570e0bcbd 100644
--- a/neutron/services/metering/drivers/iptables/iptables_driver.py
+++ b/neutron/services/metering/drivers/iptables/iptables_driver.py
@@ -135,7 +135,11 @@ class IptablesMeteringDriver(abstract_driver.MeteringAbstractDriver):
     def _process_metering_label_rules(self, rm, rules, label_chain,
                                       rules_chain):
         im = rm.iptables_manager
-        ext_dev = self.get_external_device_name(rm.router['gw_port_id'])
+        ex_gw_port = rm.router.get('gw_port_id')
+        if not ex_gw_port:
+            return
+
+        ext_dev = self.get_external_device_name(ex_gw_port)
         if not ext_dev:
             return
 
diff --git a/neutron/tests/unit/services/metering/drivers/test_iptables.py b/neutron/tests/unit/services/metering/drivers/test_iptables.py
index a33a18b2880..0b71413cdc0 100644
--- a/neutron/tests/unit/services/metering/drivers/test_iptables.py
+++ b/neutron/tests/unit/services/metering/drivers/test_iptables.py
@@ -166,6 +166,36 @@ class IptablesDriverTestCase(base.BaseTestCase):
 
         self.v4filter_inst.assert_has_calls(calls)
 
+    def test_process_metering_label_rules_with_no_gateway_router(self):
+        routers = copy.deepcopy(TEST_ROUTERS)
+        for router in routers:
+            router['gw_port_id'] = None
+
+        self.metering.add_metering_label(None, routers)
+
+        calls = [mock.call.add_chain('neutron-meter-l-c5df2fe5-c60',
+                                     wrap=False),
+                 mock.call.add_chain('neutron-meter-r-c5df2fe5-c60',
+                                     wrap=False),
+                 mock.call.add_rule('neutron-meter-FORWARD', '-j '
+                                    'neutron-meter-r-c5df2fe5-c60',
+                                    wrap=False),
+                 mock.call.add_rule('neutron-meter-l-c5df2fe5-c60',
+                                    '',
+                                    wrap=False),
+                 mock.call.add_chain('neutron-meter-l-eeef45da-c60',
+                                     wrap=False),
+                 mock.call.add_chain('neutron-meter-r-eeef45da-c60',
+                                     wrap=False),
+                 mock.call.add_rule('neutron-meter-FORWARD', '-j '
+                                    'neutron-meter-r-eeef45da-c60',
+                                    wrap=False),
+                 mock.call.add_rule('neutron-meter-l-eeef45da-c60',
+                                    '',
+                                    wrap=False)]
+
+        self.v4filter_inst.assert_has_calls(calls, any_order=False)
+
     def test_add_metering_label_with_rules(self):
         routers = copy.deepcopy(TEST_ROUTERS)
         routers[1]['_metering_labels'][0]['rules'][0].update({