diff --git a/neutron/agent/dhcp/agent.py b/neutron/agent/dhcp/agent.py
index 5b2b5dd036f..38cb6717723 100644
--- a/neutron/agent/dhcp/agent.py
+++ b/neutron/agent/dhcp/agent.py
@@ -541,11 +541,14 @@ class DhcpAgent(manager.Manager):
             return
         new_ips = {i['ip_address'] for i in created_port['fixed_ips']}
         for port_cached in network.ports:
-            # if there are other ports cached with the same ip address in
-            # the same network this indicate that the cache is out of sync
+            # if in the same network there are ports cached with the same
+            # ip address but different MAC address and/or different id,
+            # this indicate that the cache is out of sync
             cached_ips = {i['ip_address']
                           for i in port_cached['fixed_ips']}
-            if new_ips.intersection(cached_ips):
+            if (new_ips.intersection(cached_ips) and
+                (created_port['id'] != port_cached['id'] or
+                 created_port['mac_address'] != port_cached['mac_address'])):
                 self.schedule_resync("Duplicate IP addresses found, "
                                      "DHCP cache is out of sync",
                                      created_port.network_id)
diff --git a/neutron/tests/unit/agent/dhcp/test_agent.py b/neutron/tests/unit/agent/dhcp/test_agent.py
index 3139a15a05a..62764f7a603 100644
--- a/neutron/tests/unit/agent/dhcp/test_agent.py
+++ b/neutron/tests/unit/agent/dhcp/test_agent.py
@@ -1137,6 +1137,21 @@ class TestDhcpAgentEventHandler(base.BaseTestCase):
         self.reload_allocations.assert_called_once_with(fake_port2,
                                                         fake_network)
 
+    def test_port_create_end_no_resync_if_same_port_already_in_cache(self):
+        self.reload_allocations_p = mock.patch.object(self.dhcp,
+                                                      'reload_allocations')
+        self.reload_allocations = self.reload_allocations_p.start()
+        payload = dict(port=copy.deepcopy(fake_port2))
+        cached_port = copy.deepcopy(fake_port2)
+        new_fake_network = copy.deepcopy(fake_network)
+        new_fake_network.ports = [cached_port]
+        self.cache.get_network_by_id.return_value = new_fake_network
+        self.dhcp.port_create_end(None, payload)
+        self.dhcp._process_resource_update()
+        self.reload_allocations.assert_called_once_with(fake_port2,
+                                                        new_fake_network)
+        self.schedule_resync.assert_not_called()
+
     def test_port_update_change_ip_on_port(self):
         payload = dict(port=fake_port1, priority=FAKE_PRIORITY)
         self.cache.get_network_by_id.return_value = fake_network