diff --git a/neutron/tests/common/net_helpers.py b/neutron/tests/common/net_helpers.py
index 4f274935448..b436bdd0dd2 100644
--- a/neutron/tests/common/net_helpers.py
+++ b/neutron/tests/common/net_helpers.py
@@ -28,6 +28,7 @@ import time
 import fixtures
 import netaddr
 from neutron_lib import constants as n_const
+from neutron_lib import exceptions as n_exc
 from oslo_config import cfg
 from oslo_log import log as logging
 from oslo_utils import uuidutils
@@ -554,13 +555,22 @@ class NetcatTester(object):
         proc = RootHelperProcess(cmd, namespace=namespace)
         return proc
 
-    def stop_processes(self):
+    def stop_processes(self, skip_errors=None):
+        skip_errors = (['No such process'] if skip_errors is None
+                       else skip_errors)
         for proc_attr in ('_client_process', '_server_process'):
             proc = getattr(self, proc_attr)
             if proc:
-                if proc.poll() is None:
-                    proc.kill()
-                    proc.wait()
+                try:
+                    if proc.poll() is None:
+                        proc.kill()
+                        proc.wait()
+                except n_exc.ProcessExecutionError as exc:
+                    for skip_error in skip_errors:
+                        if skip_error in str(exc):
+                            break
+                    else:
+                        raise exc
                 setattr(self, proc_attr, None)
 
 
diff --git a/neutron/tests/functional/tests/common/test_net_helpers.py b/neutron/tests/functional/tests/common/test_net_helpers.py
new file mode 100644
index 00000000000..56be53ebe4f
--- /dev/null
+++ b/neutron/tests/functional/tests/common/test_net_helpers.py
@@ -0,0 +1,75 @@
+# Copyright 2019 Red Hat, Inc.
+#
+#    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.
+
+import signal
+
+import mock
+
+from neutron_lib import exceptions as n_exc
+
+from neutron.agent.linux import ip_lib
+from neutron.agent.linux import utils
+from neutron.common import utils as n_utils
+from neutron.tests.common import net_helpers
+from neutron.tests.functional import base
+
+
+class NetcatTesterTestCase(base.BaseSudoTestCase):
+
+    def setUp(self):
+        super(NetcatTesterTestCase, self).setUp()
+        self.ns1 = self.useFixture(net_helpers.NamespaceFixture('nc-')).name
+        self.ns2 = self.useFixture(net_helpers.NamespaceFixture('nc-')).name
+        self.nc = net_helpers.NetcatTester(self.ns1, self.ns2, '10.30.0.2',
+                                           '1234', 'tcp')
+        ip_wrapper = ip_lib.IPWrapper(namespace=self.ns1)
+        veth1, veth2 = ip_wrapper.add_veth('veth1', 'veth2', self.ns2)
+        veth1.link.set_up()
+        veth1.addr.add('10.30.0.1/24')
+        veth2.link.set_up()
+        veth2.addr.add('10.30.0.2/24')
+
+    def test_stop_process(self):
+        self.nc.test_connectivity()
+        server_pid = self.nc.server_process.child_pid
+        client_pid = self.nc.client_process.child_pid
+        self.assertTrue(utils.process_is_running(server_pid))
+        self.assertTrue(utils.process_is_running(client_pid))
+
+        self.nc.stop_processes()
+        self.assertFalse(utils.process_is_running(server_pid))
+        self.assertFalse(utils.process_is_running(client_pid))
+
+    def test_stop_process_no_process(self):
+        self.nc.test_connectivity()
+        client_pid = self.nc.client_process.child_pid
+        utils.execute(['kill', '-%d' % signal.SIGKILL, client_pid],
+                      run_as_root=True)
+        n_utils.wait_until_true(
+            lambda: not utils.process_is_running(client_pid), timeout=5)
+        with mock.patch.object(net_helpers.RootHelperProcess, 'poll',
+                               return_value=None):
+            self.assertRaises(n_exc.ProcessExecutionError,
+                              self.nc.stop_processes,
+                              skip_errors=[])
+
+    def test_stop_process_no_process_skip_no_process_exception(self):
+        self.nc.test_connectivity()
+        server_pid = self.nc.server_process.child_pid
+        utils.execute(['kill', '-%d' % signal.SIGKILL, server_pid],
+                      run_as_root=True)
+
+        with mock.patch.object(net_helpers.RootHelperProcess, 'poll',
+                               side_effect=[None, True, None, True]):
+            self.nc.stop_processes()