diff --git a/ryu/tests/integrated/bgp/base.py b/ryu/tests/integrated/bgp/base.py
index 8d4bb6fe..39186bb6 100644
--- a/ryu/tests/integrated/bgp/base.py
+++ b/ryu/tests/integrated/bgp/base.py
@@ -16,6 +16,7 @@
 
 from __future__ import absolute_import
 
+import logging
 import unittest
 
 from ryu.tests.integrated.common import docker_base as ctn_base
@@ -23,16 +24,17 @@ from ryu.tests.integrated.common import ryubgp
 from ryu.tests.integrated.common import quagga
 
 
-class BgpSpeakerTestBase(unittest.TestCase):
+LOG = logging.getLogger(__name__)
 
+
+class BgpSpeakerTestBase(unittest.TestCase):
+    images = []
+    containers = []
+    bridges = []
     checktime = 120
 
     @classmethod
     def setUpClass(cls):
-        cls.images = []
-        cls.containers = []
-        cls.bridges = []
-
         cls.brdc1 = ctn_base.Bridge(name='brdc1',
                                     subnet='192.168.10.0/24')
         cls.bridges.append(cls.brdc1)
@@ -72,7 +74,7 @@ class BgpSpeakerTestBase(unittest.TestCase):
             try:
                 ctn.stop()
             except ctn_base.CommandError as e:
-                pass
+                LOG.exception('Exception when stopping containers: %s', e)
             ctn.remove()
         for br in cls.bridges:
             br.delete()
diff --git a/ryu/tests/integrated/bgp/base_ip6.py b/ryu/tests/integrated/bgp/base_ip6.py
index c68a2738..ebe4e5b6 100644
--- a/ryu/tests/integrated/bgp/base_ip6.py
+++ b/ryu/tests/integrated/bgp/base_ip6.py
@@ -16,6 +16,7 @@
 
 from __future__ import absolute_import
 
+import logging
 import unittest
 
 from ryu.tests.integrated.common import docker_base as ctn_base
@@ -23,16 +24,17 @@ from ryu.tests.integrated.common import ryubgp
 from ryu.tests.integrated.common import quagga
 
 
-class BgpSpeakerTestBase(unittest.TestCase):
+LOG = logging.getLogger(__name__)
 
+
+class BgpSpeakerTestBase(unittest.TestCase):
+    images = []
+    containers = []
+    bridges = []
     checktime = 120
 
     @classmethod
     def setUpClass(cls):
-        cls.images = []
-        cls.containers = []
-        cls.bridges = []
-
         cls.brdc1 = ctn_base.Bridge(name='brip6dc1',
                                     subnet='2001:10::/32')
         cls.bridges.append(cls.brdc1)
@@ -72,7 +74,7 @@ class BgpSpeakerTestBase(unittest.TestCase):
             try:
                 ctn.stop()
             except ctn_base.CommandError as e:
-                pass
+                LOG.exception('Exception when stopping containers: %s', e)
             ctn.remove()
         for br in cls.bridges:
             br.delete()
diff --git a/ryu/tests/integrated/bgp/test_basic.py b/ryu/tests/integrated/bgp/test_basic.py
index 63211911..7c6c8cf5 100644
--- a/ryu/tests/integrated/bgp/test_basic.py
+++ b/ryu/tests/integrated/bgp/test_basic.py
@@ -18,8 +18,8 @@ from __future__ import absolute_import
 
 import time
 
-from . import base
 from ryu.tests.integrated.common import docker_base as ctn_base
+from . import base
 
 
 class BgpSpeakerBasicTest(base.BgpSpeakerTestBase):
@@ -29,7 +29,8 @@ class BgpSpeakerBasicTest(base.BgpSpeakerTestBase):
         self.r1.start_ryubgp(retry=True)
 
     def test_check_neighbor_established(self):
-        for i in range(0, self.checktime):
+        neighbor_state = ctn_base.BGP_FSM_IDLE
+        for _ in range(0, self.checktime):
             neighbor_state = self.q1.get_neighbor_state(self.r1)
             if neighbor_state == ctn_base.BGP_FSM_ESTABLISHED:
                 break
@@ -37,7 +38,8 @@ class BgpSpeakerBasicTest(base.BgpSpeakerTestBase):
         self.assertEqual(neighbor_state, ctn_base.BGP_FSM_ESTABLISHED)
 
     def test_check_rib_nexthop(self):
-        for i in range(0, self.checktime):
+        neighbor_state = ctn_base.BGP_FSM_IDLE
+        for _ in range(0, self.checktime):
             neighbor_state = self.q1.get_neighbor_state(self.r1)
             if neighbor_state == ctn_base.BGP_FSM_ESTABLISHED:
                 break
diff --git a/ryu/tests/integrated/bgp/test_ip6_basic.py b/ryu/tests/integrated/bgp/test_ip6_basic.py
index 9b27e3cf..288e9e68 100644
--- a/ryu/tests/integrated/bgp/test_ip6_basic.py
+++ b/ryu/tests/integrated/bgp/test_ip6_basic.py
@@ -18,8 +18,8 @@ from __future__ import absolute_import
 
 import time
 
-from . import base_ip6 as base
 from ryu.tests.integrated.common import docker_base as ctn_base
+from . import base_ip6 as base
 
 
 class BgpSpeakerBasicTest(base.BgpSpeakerTestBase):
@@ -29,7 +29,8 @@ class BgpSpeakerBasicTest(base.BgpSpeakerTestBase):
         self.r1.start_ryubgp(retry=True)
 
     def test_check_neighbor_established(self):
-        for i in range(0, self.checktime):
+        neighbor_state = ctn_base.BGP_FSM_IDLE
+        for _ in range(0, self.checktime):
             neighbor_state = self.q1.get_neighbor_state(self.r1)
             if neighbor_state == ctn_base.BGP_FSM_ESTABLISHED:
                 break
@@ -37,7 +38,8 @@ class BgpSpeakerBasicTest(base.BgpSpeakerTestBase):
         self.assertEqual(neighbor_state, ctn_base.BGP_FSM_ESTABLISHED)
 
     def test_check_rib_nexthop(self):
-        for i in range(0, self.checktime):
+        neighbor_state = ctn_base.BGP_FSM_IDLE
+        for _ in range(0, self.checktime):
             neighbor_state = self.q1.get_neighbor_state(self.r1)
             if neighbor_state == ctn_base.BGP_FSM_ESTABLISHED:
                 break