diff --git a/magnum/drivers/common/k8s_monitor.py b/magnum/drivers/common/k8s_monitor.py
index 7739569345..1e8cb9c285 100644
--- a/magnum/drivers/common/k8s_monitor.py
+++ b/magnum/drivers/common/k8s_monitor.py
@@ -50,10 +50,23 @@ class K8sMonitor(monitors.MonitorBase):
 
     def poll_health_status(self):
         k8s_api = k8s.create_k8s_api(self.context, self.cluster)
-        status, reason = self._poll_health_status(k8s_api)
+        if self._is_cluster_accessible():
+            status, reason = self._poll_health_status(k8s_api)
+        else:
+            status = m_fields.ClusterHealthStatus.UNKNOWN
+            reason = {"api": "The cluster %s is not accessible." %
+                      self.cluster.name}
+
         self.data['health_status'] = status
         self.data['health_status_reason'] = reason
 
+    def _is_cluster_accessible(self):
+        lb_fip = self.cluster.labels.get("master_lb_floating_ip_enabled")
+        lb_fip_enabled = strutils.bool_from_string(lb_fip)
+        return (self.cluster.floating_ip_enabled or
+                (lb_fip_enabled and
+                 self.cluster.cluster_template.master_lb_enabled))
+
     def _compute_res_util(self, res):
         res_total = 0
         for node in self.data['nodes']:
diff --git a/magnum/objects/fields.py b/magnum/objects/fields.py
index 6bb88b994d..64786f8afc 100644
--- a/magnum/objects/fields.py
+++ b/magnum/objects/fields.py
@@ -52,8 +52,9 @@ class ClusterStatus(fields.Enum):
 class ClusterHealthStatus(fields.Enum):
     HEALTHY = 'HEALTHY'
     UNHEALTHY = 'UNHEALTHY'
+    UNKNOWN = 'UNKNOWN'
 
-    ALL = (HEALTHY, UNHEALTHY)
+    ALL = (HEALTHY, UNHEALTHY, UNKNOWN)
 
     STATUS_FAILED = (UNHEALTHY)
 
diff --git a/magnum/tests/unit/conductor/test_monitors.py b/magnum/tests/unit/conductor/test_monitors.py
index 9e44272b49..73f5013f04 100644
--- a/magnum/tests/unit/conductor/test_monitors.py
+++ b/magnum/tests/unit/conductor/test_monitors.py
@@ -47,10 +47,10 @@ class MonitorsTestCase(base.TestCase):
 
     def setUp(self):
         super(MonitorsTestCase, self).setUp()
-
         cluster = utils.get_test_cluster(node_addresses=['1.2.3.4'],
                                          api_address='https://5.6.7.8:2376',
-                                         master_addresses=['10.0.0.6'])
+                                         master_addresses=['10.0.0.6'],
+                                         labels={})
         self.cluster = objects.Cluster(self.context, **cluster)
         nodegroups = utils.get_nodegroups_for_cluster(
             node_addresses=['1.2.3.4'], master_addresses=['10.0.0.6'])
@@ -511,3 +511,15 @@ class MonitorsTestCase(base.TestCase):
         self.assertEqual(self.k8s_monitor.data['health_status_reason'],
                          {'api': 'ok', 'k8s-cluster-node-0.Ready': False,
                           'api': 'ok', 'k8s-cluster-node-1.Ready': True})
+
+    @mock.patch('magnum.conductor.k8s_api.create_k8s_api')
+    def test_k8s_monitor_health_unreachable_cluster(self, mock_k8s_api):
+        mock_nodes = mock.MagicMock()
+        mock_node = mock.MagicMock()
+        mock_node.status = mock.MagicMock()
+        mock_nodes.items = [mock_node]
+        self.k8s_monitor.cluster.floating_ip_enabled = False
+
+        self.k8s_monitor.poll_health_status()
+        self.assertEqual(self.k8s_monitor.data['health_status'],
+                         m_fields.ClusterHealthStatus.UNKNOWN)
diff --git a/magnum/tests/unit/objects/test_objects.py b/magnum/tests/unit/objects/test_objects.py
index ec565133a8..5aa0eceed1 100644
--- a/magnum/tests/unit/objects/test_objects.py
+++ b/magnum/tests/unit/objects/test_objects.py
@@ -355,7 +355,7 @@ class TestObject(test_base.TestCase, _TestObject):
 # For more information on object version testing, read
 # https://docs.openstack.org/magnum/latest/contributor/objects.html
 object_data = {
-    'Cluster': '1.21-11ab13dfd5cb53578d398008d758dab8',
+    'Cluster': '1.21-e28dc2dd599433a6249f7901ebf7b162',
     'ClusterTemplate': '1.19-3b0b2b3933d0955abf3ab40111744960',
     'Certificate': '1.1-1924dc077daa844f0f9076332ef96815',
     'MyObj': '1.0-34c4b1aadefd177b13f9a2f894cc23cd',