diff --git a/dragonflow/controller/topology.py b/dragonflow/controller/topology.py
index 8a78e5c74..cd3477df9 100644
--- a/dragonflow/controller/topology.py
+++ b/dragonflow/controller/topology.py
@@ -64,9 +64,6 @@ class Topology(object):
         @return : None
         """
         LOG.info("Ovs port updated: %s", ovs_port)
-        # ignore port that misses some parameters
-        if not self._check_ovs_port_integrity(ovs_port):
-            return
         port_id = ovs_port.id
         old_port = self.ovs_ports.get(port_id)
         if old_port is None:
@@ -122,24 +119,6 @@ class Topology(object):
         finally:
             del self.ovs_ports[ovs_port.id]
 
-    def _check_ovs_port_integrity(self, ovs_port):
-        """
-        There are some cases that some para of ovs port is missing
-        then the event will be discarded
-        """
-
-        ofport = ovs_port.ofport
-        port_type = ovs_port.type
-
-        if (ofport is None) or (ofport < 0) or (port_type is None):
-            return False
-
-        if (port_type == constants.OVS_VM_INTERFACE and
-                ovs_port.lport is None):
-            return False
-
-        return True
-
     def _tunnel_port_added(self, ovs_port):
         self._tunnel_port_updated(ovs_port)
 
diff --git a/dragonflow/ovsdb/impl_idl.py b/dragonflow/ovsdb/impl_idl.py
index 52e528914..3bd2555d9 100644
--- a/dragonflow/ovsdb/impl_idl.py
+++ b/dragonflow/ovsdb/impl_idl.py
@@ -72,7 +72,7 @@ _HANDLED_INTERFACE_TYPES = (
 )
 
 
-def _is_ovsport_update_valid(ovsport):
+def _is_ovsport_update_valid(action, ovsport):
     if ovsport.name == cfg.CONF.df_metadata.metadata_interface:
         return True
 
@@ -82,6 +82,16 @@ def _is_ovsport_update_valid(ovsport):
     if ovsport.name.startswith('qg'):
         return False
 
+    if (ovsport.type == constants.OVS_VM_INTERFACE and
+            ovsport.lport is None):
+        return False
+
+    if action == 'set':
+        # No need for 'updated' event if the ofport is being deleted
+        ofport = ovsport.ofport
+        if (ofport is None) or (ofport < 0):
+            return False
+
     return True
 
 
@@ -98,7 +108,7 @@ class DFIdl(idl.Idl):
 
         local_interface = ovs.OvsPort.from_idl_row(row)
         action = event if event != 'update' else 'set'
-        if _is_ovsport_update_valid(local_interface):
+        if _is_ovsport_update_valid(action, local_interface):
             self.nb_api.db_change_callback(
                 local_interface.table_name,
                 local_interface.id,
diff --git a/dragonflow/tests/unit/test_ovsdb_monitor.py b/dragonflow/tests/unit/test_ovsdb_monitor.py
new file mode 100644
index 000000000..5f6985bfe
--- /dev/null
+++ b/dragonflow/tests/unit/test_ovsdb_monitor.py
@@ -0,0 +1,76 @@
+#    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 dragonflow.common import constants
+from dragonflow.db.models import ovs
+from dragonflow.ovsdb import impl_idl
+from dragonflow.tests import base as tests_base
+
+
+class TestDFIdl(tests_base.BaseTestCase):
+    def setUp(self):
+        super(TestDFIdl, self).setUp()
+
+    def test_port_update_qg(self):
+        self.assertFalse(
+            impl_idl._is_ovsport_update_valid(
+                'set',
+                ovs.OvsPort(
+                    ofport=1,
+                    name='qg-some-uuid',
+                ),
+            ),
+        )
+
+    def test_port_update_no_ofport(self):
+        self.assertFalse(
+            impl_idl._is_ovsport_update_valid(
+                'set',
+                ovs.OvsPort(
+                    name='tap-uuid',
+                ),
+            ),
+        )
+
+    def test_port_update_neg_ofport(self):
+        self.assertFalse(
+            impl_idl._is_ovsport_update_valid(
+                'set',
+                ovs.OvsPort(
+                    ofport=-1,
+                    name='tap-uuid',
+                ),
+            ),
+        )
+
+    def test_port_update_bad_type(self):
+        self.assertFalse(
+            impl_idl._is_ovsport_update_valid(
+                'set',
+                ovs.OvsPort(
+                    ofport=1,
+                    type=constants.OVS_PATCH_INTERFACE,
+                    name='tap-uuid',
+                ),
+            ),
+        )
+
+    def test_port_update_missing_lport(self):
+        self.assertFalse(
+            impl_idl._is_ovsport_update_valid(
+                'set',
+                ovs.OvsPort(
+                    ofport=1,
+                    type=constants.OVS_VM_INTERFACE,
+                    name='tap-uuid',
+                ),
+            ),
+        )
diff --git a/dragonflow/tests/unit/test_topology.py b/dragonflow/tests/unit/test_topology.py
index 6db9bb3ed..1239bd3c4 100644
--- a/dragonflow/tests/unit/test_topology.py
+++ b/dragonflow/tests/unit/test_topology.py
@@ -106,11 +106,6 @@ class TestTopology(test_app_base.DFAppTestBase):
         self.nb_api.subscriber.unregister_topic.assert_called_once_with(
             test_app_base.fake_local_port1.topic)
 
-        self.fake_invalid_ovs_port.ofport = -1
-        self.controller.update.reset_mock()
-        self.topology.ovs_port_updated(self.fake_invalid_ovs_port)
-        self.controller.update.assert_not_called()
-
     def test_vm_online_after_topology_pulled(self):
         self.nb_api.get_all.side_effect = nb_api_get_all_func(
             test_app_base.fake_logic_switch1,