tests: refactor. Replace literal constant w/ named constant.
[vpp.git] / test / test_ip4.py
index b6553db..346904a 100644 (file)
@@ -4,6 +4,7 @@ import random
 import socket
 import unittest
 
+import scapy.compat
 from scapy.contrib.mpls import MPLS
 from scapy.layers.inet import IP, UDP, TCP, ICMP, icmptypes, icmpcodes
 from scapy.layers.l2 import Ether, Dot1Q, ARP
@@ -17,10 +18,20 @@ from vpp_ip_route import VppIpRoute, VppRoutePath, VppIpMRoute, \
     VppMplsTable, VppIpTable
 from vpp_sub_interface import VppSubInterface, VppDot1QSubint, VppDot1ADSubint
 
+NUM_PKTS = 67
+
 
 class TestIPv4(VppTestCase):
     """ IPv4 Test Case """
 
+    @classmethod
+    def setUpClass(cls):
+        super(TestIPv4, cls).setUpClass()
+
+    @classmethod
+    def tearDownClass(cls):
+        super(TestIPv4, cls).tearDownClass()
+
     def setUp(self):
         """
         Perform test setup before test case.
@@ -73,9 +84,10 @@ class TestIPv4(VppTestCase):
     def tearDown(self):
         """Run standard test teardown and log ``show ip arp``."""
         super(TestIPv4, self).tearDown()
-        if not self.vpp_dead:
-            self.logger.info(self.vapi.cli("show ip arp"))
-            # info(self.vapi.cli("show ip fib"))  # many entries
+
+    def show_commands_at_teardown(self):
+        self.logger.info(self.vapi.cli("show ip arp"))
+        # info(self.vapi.cli("show ip fib"))  # many entries
 
     def config_fib_entries(self, count):
         """For each interface add to the FIB table *count* routes to
@@ -95,8 +107,9 @@ class TestIPv4(VppTestCase):
         for i in self.interfaces:
             next_hop_address = i.local_ip4n
             for j in range(count / n_int):
-                self.vapi.ip_add_del_route(
-                    dest_addr, dest_addr_len, next_hop_address)
+                self.vapi.ip_add_del_route(dst_address=dest_addr,
+                                           dst_address_length=dest_addr_len,
+                                           next_hop_address=next_hop_address)
                 counter += 1
                 if counter / count * 100 > percent:
                     self.logger.info("Configure %d FIB entries .. %d%% done" %
@@ -168,7 +181,7 @@ class TestIPv4(VppTestCase):
             try:
                 ip = packet[IP]
                 udp = packet[UDP]
-                payload_info = self.payload_to_info(str(packet[Raw]))
+                payload_info = self.payload_to_info(packet[Raw])
                 packet_index = payload_info.index
                 self.assertEqual(payload_info.dst, dst_sw_if_index)
                 self.logger.debug(
@@ -227,6 +240,14 @@ class TestIPv4(VppTestCase):
 class TestICMPEcho(VppTestCase):
     """ ICMP Echo Test Case """
 
+    @classmethod
+    def setUpClass(cls):
+        super(TestICMPEcho, cls).setUpClass()
+
+    @classmethod
+    def tearDownClass(cls):
+        super(TestICMPEcho, cls).tearDownClass()
+
     def setUp(self):
         super(TestICMPEcho, self).setUp()
 
@@ -310,9 +331,10 @@ class TestIPv4FibCrud(VppTestCase):
         dest_addr_len = 32
         n_next_hop_addr = socket.inet_pton(socket.AF_INET, next_hop_addr)
         for _ in range(count):
-            n_dest_addr = '{:08x}'.format(dest_addr).decode('hex')
-            self.vapi.ip_add_del_route(n_dest_addr, dest_addr_len,
-                                       n_next_hop_addr)
+            n_dest_addr = binascii.unhexlify('{:08x}'.format(dest_addr))
+            self.vapi.ip_add_del_route(dst_address=n_dest_addr,
+                                       dst_address_length=dest_addr_len,
+                                       next_hop_address=n_next_hop_addr)
             added_ips.append(socket.inet_ntoa(n_dest_addr))
             dest_addr += 1
         return added_ips
@@ -325,9 +347,11 @@ class TestIPv4FibCrud(VppTestCase):
         dest_addr_len = 32
         n_next_hop_addr = socket.inet_pton(socket.AF_INET, next_hop_addr)
         for _ in range(count):
-            n_dest_addr = '{:08x}'.format(dest_addr).decode('hex')
-            self.vapi.ip_add_del_route(n_dest_addr, dest_addr_len,
-                                       n_next_hop_addr, is_add=0)
+            n_dest_addr = binascii.unhexlify('{:08x}'.format(dest_addr))
+            self.vapi.ip_add_del_route(dst_address=n_dest_addr,
+                                       dst_address_length=dest_addr_len,
+                                       next_hop_address=n_next_hop_addr,
+                                       is_add=0)
             removed_ips.append(socket.inet_ntoa(n_dest_addr))
             dest_addr += 1
         return removed_ips
@@ -351,8 +375,8 @@ class TestIPv4FibCrud(VppTestCase):
 
     def _find_ip_match(self, find_in, pkt):
         for p in find_in:
-            if self.payload_to_info(str(p[Raw])) == \
-                    self.payload_to_info(str(pkt[Raw])):
+            if self.payload_to_info(p[Raw]) == \
+                    self.payload_to_info(pkt[Raw]):
                 if p[IP].src != pkt[IP].src:
                     break
                 if p[IP].dst != pkt[IP].dst:
@@ -437,6 +461,10 @@ class TestIPv4FibCrud(VppTestCase):
             super(TestIPv4FibCrud, cls).tearDownClass()
             raise
 
+    @classmethod
+    def tearDownClass(cls):
+        super(TestIPv4FibCrud, cls).tearDownClass()
+
     def setUp(self):
         super(TestIPv4FibCrud, self).setUp()
         self.reset_packet_infos()
@@ -563,6 +591,14 @@ class TestIPv4FibCrud(VppTestCase):
 class TestIPNull(VppTestCase):
     """ IPv4 routes via NULL """
 
+    @classmethod
+    def setUpClass(cls):
+        super(TestIPNull, cls).setUpClass()
+
+    @classmethod
+    def tearDownClass(cls):
+        super(TestIPNull, cls).tearDownClass()
+
     def setUp(self):
         super(TestIPNull, self).setUp()
 
@@ -653,7 +689,7 @@ class TestIPNull(VppTestCase):
                                       self.pg1.sw_if_index)])
         r1.add_vpp_config()
 
-        rx = self.send_and_expect(self.pg0, p * 65, self.pg1)
+        rx = self.send_and_expect(self.pg0, p * NUM_PKTS, self.pg1)
 
         #
         # insert a more specific as a drop
@@ -661,14 +697,22 @@ class TestIPNull(VppTestCase):
         r2 = VppIpRoute(self, "1.1.1.1", 32, [], is_drop=1)
         r2.add_vpp_config()
 
-        self.send_and_assert_no_replies(self.pg0, p * 65, "Drop Route")
+        self.send_and_assert_no_replies(self.pg0, p * NUM_PKTS, "Drop Route")
         r2.remove_vpp_config()
-        rx = self.send_and_expect(self.pg0, p * 65, self.pg1)
+        rx = self.send_and_expect(self.pg0, p * NUM_PKTS, self.pg1)
 
 
 class TestIPDisabled(VppTestCase):
     """ IPv4 disabled """
 
+    @classmethod
+    def setUpClass(cls):
+        super(TestIPDisabled, cls).setUpClass()
+
+    @classmethod
+    def tearDownClass(cls):
+        super(TestIPDisabled, cls).tearDownClass()
+
     def setUp(self):
         super(TestIPDisabled, self).setUp()
 
@@ -757,13 +801,21 @@ class TestIPDisabled(VppTestCase):
 class TestIPSubNets(VppTestCase):
     """ IPv4 Subnets """
 
+    @classmethod
+    def setUpClass(cls):
+        super(TestIPSubNets, cls).setUpClass()
+
+    @classmethod
+    def tearDownClass(cls):
+        super(TestIPSubNets, cls).tearDownClass()
+
     def setUp(self):
         super(TestIPSubNets, self).setUp()
 
         # create a 2 pg interfaces
         self.create_pg_interfaces(range(2))
 
-        # pg0 we will use to experiemnt
+        # pg0 we will use to experiment
         self.pg0.admin_up()
 
         # pg1 is setup normally
@@ -870,6 +922,14 @@ class TestIPSubNets(VppTestCase):
 class TestIPLoadBalance(VppTestCase):
     """ IPv4 Load-Balancing """
 
+    @classmethod
+    def setUpClass(cls):
+        super(TestIPLoadBalance, cls).setUpClass()
+
+    @classmethod
+    def tearDownClass(cls):
+        super(TestIPLoadBalance, cls).tearDownClass()
+
     def setUp(self):
         super(TestIPLoadBalance, self).setUp()
 
@@ -894,9 +954,13 @@ class TestIPLoadBalance(VppTestCase):
         input.add_stream(pkts)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
+        rxs = []
         for oo in outputs:
             rx = oo._get_capture(1)
             self.assertNotEqual(0, len(rx))
+            for r in rx:
+                rxs.append(r)
+        return rxs
 
     def send_and_expect_one_itf(self, input, pkts, itf):
         input.add_stream(pkts)
@@ -919,7 +983,7 @@ class TestIPLoadBalance(VppTestCase):
         src_ip_pkts = []
         src_mpls_pkts = []
 
-        for ii in range(65):
+        for ii in range(NUM_PKTS):
             port_ip_hdr = (IP(dst="10.0.0.1", src="20.0.0.1") /
                            UDP(sport=1234, dport=1234 + ii) /
                            Raw('\xa5' * 100))
@@ -958,7 +1022,7 @@ class TestIPLoadBalance(VppTestCase):
         #    src,dst
         # We are not going to ensure equal amounts of packets across each link,
         # since the hash algorithm is statistical and therefore this can never
-        # be guaranteed. But wuth 64 different packets we do expect some
+        # be guaranteed. But with 64 different packets we do expect some
         # balancing. So instead just ensure there is traffic on each link.
         #
         self.send_and_expect_load_balancing(self.pg0, port_ip_pkts,
@@ -975,7 +1039,7 @@ class TestIPLoadBalance(VppTestCase):
         #  - now only the stream with differing source address will
         #    load-balance
         #
-        self.vapi.set_ip_flow_hash(0, src=1, dst=1, sport=0, dport=0)
+        self.vapi.set_ip_flow_hash(vrf_id=0, src=1, dst=1, sport=0, dport=0)
 
         self.send_and_expect_load_balancing(self.pg0, src_ip_pkts,
                                             [self.pg1, self.pg2])
@@ -987,7 +1051,7 @@ class TestIPLoadBalance(VppTestCase):
         #
         # change the flow hash config back to defaults
         #
-        self.vapi.set_ip_flow_hash(0, src=1, dst=1, sport=1, dport=1)
+        self.vapi.set_ip_flow_hash(vrf_id=0, src=1, dst=1, sport=1, dport=1)
 
         #
         # Recursive prefixes
@@ -1032,6 +1096,53 @@ class TestIPLoadBalance(VppTestCase):
                                             [self.pg1, self.pg2,
                                              self.pg3, self.pg4])
 
+        #
+        # bring down pg1 expect LB to adjust to use only those that are pu
+        #
+        self.pg1.link_down()
+
+        rx = self.send_and_expect_load_balancing(self.pg0, src_pkts,
+                                                 [self.pg2, self.pg3,
+                                                  self.pg4])
+        self.assertEqual(len(src_pkts), len(rx))
+
+        #
+        # bring down pg2 expect LB to adjust to use only those that are pu
+        #
+        self.pg2.link_down()
+
+        rx = self.send_and_expect_load_balancing(self.pg0, src_pkts,
+                                                 [self.pg3, self.pg4])
+        self.assertEqual(len(src_pkts), len(rx))
+
+        #
+        # bring the links back up - expect LB over all again
+        #
+        self.pg1.link_up()
+        self.pg2.link_up()
+
+        rx = self.send_and_expect_load_balancing(self.pg0, src_pkts,
+                                                 [self.pg1, self.pg2,
+                                                  self.pg3, self.pg4])
+        self.assertEqual(len(src_pkts), len(rx))
+
+        #
+        # The same link-up/down but this time admin state
+        #
+        self.pg1.admin_down()
+        self.pg2.admin_down()
+        rx = self.send_and_expect_load_balancing(self.pg0, src_pkts,
+                                                 [self.pg3, self.pg4])
+        self.assertEqual(len(src_pkts), len(rx))
+        self.pg1.admin_up()
+        self.pg2.admin_up()
+        self.pg1.resolve_arp()
+        self.pg2.resolve_arp()
+        rx = self.send_and_expect_load_balancing(self.pg0, src_pkts,
+                                                 [self.pg1, self.pg2,
+                                                  self.pg3, self.pg4])
+        self.assertEqual(len(src_pkts), len(rx))
+
         #
         # Recursive prefixes
         #  - testing that 2 stages of load-balancing, no choices
@@ -1055,15 +1166,53 @@ class TestIPLoadBalance(VppTestCase):
         route_1_1_1_2.add_vpp_config()
 
         #
-        # inject the packet on pg0 - expect load-balancing across all 4 paths
+        # inject the packet on pg0 - rx only on via routes output interface
         #
         self.vapi.cli("clear trace")
         self.send_and_expect_one_itf(self.pg0, port_pkts, self.pg3)
 
+        #
+        # Add a LB route in the presence of a down link - expect no
+        # packets over the down link
+        #
+        self.pg3.link_down()
+
+        route_10_0_0_3 = VppIpRoute(self, "10.0.0.3", 32,
+                                    [VppRoutePath(self.pg3.remote_ip4,
+                                                  self.pg3.sw_if_index),
+                                     VppRoutePath(self.pg4.remote_ip4,
+                                                  self.pg4.sw_if_index)])
+        route_10_0_0_3.add_vpp_config()
+
+        port_pkts = []
+        for ii in range(257):
+            port_pkts.append(Ether(src=self.pg0.remote_mac,
+                                   dst=self.pg0.local_mac) /
+                             IP(dst="10.0.0.3", src="20.0.0.2") /
+                             UDP(sport=1234, dport=1234 + ii) /
+                             Raw('\xa5' * 100))
+
+        self.send_and_expect_one_itf(self.pg0, port_pkts, self.pg4)
+
+        # bring the link back up
+        self.pg3.link_up()
+
+        rx = self.send_and_expect_load_balancing(self.pg0, port_pkts,
+                                                 [self.pg3, self.pg4])
+        self.assertEqual(len(src_pkts), len(rx))
+
 
 class TestIPVlan0(VppTestCase):
     """ IPv4 VLAN-0 """
 
+    @classmethod
+    def setUpClass(cls):
+        super(TestIPVlan0, cls).setUpClass()
+
+    @classmethod
+    def tearDownClass(cls):
+        super(TestIPVlan0, cls).tearDownClass()
+
     def setUp(self):
         super(TestIPVlan0, self).setUp()
 
@@ -1093,7 +1242,7 @@ class TestIPVlan0(VppTestCase):
                 IP(dst=self.pg1.remote_ip4,
                    src=self.pg0.remote_ip4) /
                 UDP(sport=1234, dport=1234) /
-                Raw('\xa5' * 100)) * 65
+                Raw('\xa5' * 100)) * NUM_PKTS
 
         #
         # Expect that packets sent on VLAN-0 are forwarded on the
@@ -1105,6 +1254,14 @@ class TestIPVlan0(VppTestCase):
 class TestIPPunt(VppTestCase):
     """ IPv4 Punt Police/Redirect """
 
+    @classmethod
+    def setUpClass(cls):
+        super(TestIPPunt, cls).setUpClass()
+
+    @classmethod
+    def tearDownClass(cls):
+        super(TestIPPunt, cls).tearDownClass()
+
     def setUp(self):
         super(TestIPPunt, self).setUp()
 
@@ -1145,7 +1302,7 @@ class TestIPPunt(VppTestCase):
         #
         # add a policer
         #
-        policer = self.vapi.policer_add_del("ip4-punt", 400, 0, 10, 0,
+        policer = self.vapi.policer_add_del(b"ip4-punt", 400, 0, 10, 0,
                                             rate_type=1)
         self.vapi.ip_punt_police(policer.policer_index)
 
@@ -1155,7 +1312,7 @@ class TestIPPunt(VppTestCase):
         self.pg_start()
 
         #
-        # the number of packet recieved should be greater than 0,
+        # the number of packet received should be greater than 0,
         # but not equal to the number sent, since some were policed
         #
         rx = self.pg1._get_capture(1)
@@ -1163,10 +1320,10 @@ class TestIPPunt(VppTestCase):
         self.assertLess(len(rx), len(pkts))
 
         #
-        # remove the poilcer. back to full rx
+        # remove the policer. back to full rx
         #
         self.vapi.ip_punt_police(policer.policer_index, is_add=0)
-        self.vapi.policer_add_del("ip4-punt", 400, 0, 10, 0,
+        self.vapi.policer_add_del(b"ip4-punt", 400, 0, 10, 0,
                                   rate_type=1, is_add=0)
         self.send_and_expect(self.pg0, pkts, self.pg1)
 
@@ -1231,6 +1388,14 @@ class TestIPPunt(VppTestCase):
 class TestIPDeag(VppTestCase):
     """ IPv4 Deaggregate Routes """
 
+    @classmethod
+    def setUpClass(cls):
+        super(TestIPDeag, cls).setUpClass()
+
+    @classmethod
+    def tearDownClass(cls):
+        super(TestIPDeag, cls).tearDownClass()
+
     def setUp(self):
         super(TestIPDeag, self).setUp()
 
@@ -1340,6 +1505,14 @@ class TestIPDeag(VppTestCase):
 class TestIPInput(VppTestCase):
     """ IPv4 Input Exceptions """
 
+    @classmethod
+    def setUpClass(cls):
+        super(TestIPInput, cls).setUpClass()
+
+    @classmethod
+    def tearDownClass(cls):
+        super(TestIPInput, cls).tearDownClass()
+
     def setUp(self):
         super(TestIPInput, self).setUp()
 
@@ -1373,7 +1546,7 @@ class TestIPInput(VppTestCase):
                    UDP(sport=1234, dport=1234) /
                    Raw('\xa5' * 100))
 
-        rx = self.send_and_expect(self.pg0, p_short * 65, self.pg1)
+        rx = self.send_and_expect(self.pg0, p_short * NUM_PKTS, self.pg1)
 
         #
         # Packet too long - this is dropped
@@ -1386,7 +1559,7 @@ class TestIPInput(VppTestCase):
                   UDP(sport=1234, dport=1234) /
                   Raw('\xa5' * 100))
 
-        rx = self.send_and_assert_no_replies(self.pg0, p_long * 65,
+        rx = self.send_and_assert_no_replies(self.pg0, p_long * NUM_PKTS,
                                              "too long")
 
         #
@@ -1400,7 +1573,7 @@ class TestIPInput(VppTestCase):
                     UDP(sport=1234, dport=1234) /
                     Raw('\xa5' * 100))
 
-        rx = self.send_and_assert_no_replies(self.pg0, p_chksum * 65,
+        rx = self.send_and_assert_no_replies(self.pg0, p_chksum * NUM_PKTS,
                                              "bad checksum")
 
         #
@@ -1414,7 +1587,7 @@ class TestIPInput(VppTestCase):
                  UDP(sport=1234, dport=1234) /
                  Raw('\xa5' * 100))
 
-        rx = self.send_and_assert_no_replies(self.pg0, p_ver * 65,
+        rx = self.send_and_assert_no_replies(self.pg0, p_ver * NUM_PKTS,
                                              "funky version")
 
         #
@@ -1428,7 +1601,7 @@ class TestIPInput(VppTestCase):
                   UDP(sport=1234, dport=1234) /
                   Raw('\xa5' * 100))
 
-        rx = self.send_and_assert_no_replies(self.pg0, p_frag * 65,
+        rx = self.send_and_assert_no_replies(self.pg0, p_frag * NUM_PKTS,
                                              "frag offset")
 
         #
@@ -1442,7 +1615,7 @@ class TestIPInput(VppTestCase):
                  UDP(sport=1234, dport=1234) /
                  Raw('\xa5' * 100))
 
-        rx = self.send_and_expect(self.pg0, p_ttl * 65, self.pg0)
+        rx = self.send_and_expect(self.pg0, p_ttl * NUM_PKTS, self.pg0)
 
         rx = rx[0]
         icmp = rx[ICMP]
@@ -1466,7 +1639,7 @@ class TestIPInput(VppTestCase):
 
         self.vapi.sw_interface_set_mtu(self.pg1.sw_if_index, [1500, 0, 0, 0])
 
-        rx = self.send_and_expect(self.pg0, p_mtu * 65, self.pg0)
+        rx = self.send_and_expect(self.pg0, p_mtu * NUM_PKTS, self.pg0)
         rx = rx[0]
         icmp = rx[ICMP]
 
@@ -1477,7 +1650,7 @@ class TestIPInput(VppTestCase):
         self.assertEqual(icmp.dst, self.pg1.remote_ip4)
 
         self.vapi.sw_interface_set_mtu(self.pg1.sw_if_index, [2500, 0, 0, 0])
-        rx = self.send_and_expect(self.pg0, p_mtu * 65, self.pg1)
+        rx = self.send_and_expect(self.pg0, p_mtu * NUM_PKTS, self.pg1)
 
         # Reset MTU for subsequent tests
         self.vapi.sw_interface_set_mtu(self.pg1.sw_if_index, [9000, 0, 0, 0])
@@ -1505,6 +1678,14 @@ class TestIPInput(VppTestCase):
 class TestIPDirectedBroadcast(VppTestCase):
     """ IPv4 Directed Broadcast """
 
+    @classmethod
+    def setUpClass(cls):
+        super(TestIPDirectedBroadcast, cls).setUpClass()
+
+    @classmethod
+    def tearDownClass(cls):
+        super(TestIPDirectedBroadcast, cls).tearDownClass()
+
     def setUp(self):
         super(TestIPDirectedBroadcast, self).setUp()
 
@@ -1548,10 +1729,10 @@ class TestIPDirectedBroadcast(VppTestCase):
         #
         # test packet is L2 broadcast
         #
-        rx = self.send_and_expect(self.pg1, p0 * 65, self.pg0)
+        rx = self.send_and_expect(self.pg1, p0 * NUM_PKTS, self.pg0)
         self.assertTrue(rx[0][Ether].dst, "ff:ff:ff:ff:ff:ff")
 
-        self.send_and_assert_no_replies(self.pg0, p1 * 65,
+        self.send_and_assert_no_replies(self.pg0, p1 * NUM_PKTS,
                                         "directed broadcast disabled")
 
         #
@@ -1559,12 +1740,12 @@ class TestIPDirectedBroadcast(VppTestCase):
         #
         self.vapi.sw_interface_set_ip_directed_broadcast(
             self.pg0.sw_if_index, 0)
-        self.send_and_assert_no_replies(self.pg1, p0 * 65,
+        self.send_and_assert_no_replies(self.pg1, p0 * NUM_PKTS,
                                         "directed broadcast disabled")
 
         self.vapi.sw_interface_set_ip_directed_broadcast(
             self.pg0.sw_if_index, 1)
-        rx = self.send_and_expect(self.pg1, p0 * 65, self.pg0)
+        rx = self.send_and_expect(self.pg1, p0 * NUM_PKTS, self.pg0)
 
         self.pg0.unconfig_ip4()
         self.pg1.unconfig_ip4()
@@ -1573,6 +1754,14 @@ class TestIPDirectedBroadcast(VppTestCase):
 class TestIPLPM(VppTestCase):
     """ IPv4 longest Prefix Match """
 
+    @classmethod
+    def setUpClass(cls):
+        super(TestIPLPM, cls).setUpClass()
+
+    @classmethod
+    def tearDownClass(cls):
+        super(TestIPLPM, cls).tearDownClass()
+
     def setUp(self):
         super(TestIPLPM, self).setUp()
 
@@ -1615,8 +1804,8 @@ class TestIPLPM(VppTestCase):
                 Raw('\xa5' * 2000))
 
         self.logger.info(self.vapi.cli("sh ip fib mtrie"))
-        rx = self.send_and_expect(self.pg0, p_8 * 65, self.pg2)
-        rx = self.send_and_expect(self.pg0, p_24 * 65, self.pg1)
+        rx = self.send_and_expect(self.pg0, p_8 * NUM_PKTS, self.pg2)
+        rx = self.send_and_expect(self.pg0, p_24 * NUM_PKTS, self.pg1)
 
 
 class TestIPv4Frag(VppTestCase):
@@ -1636,6 +1825,10 @@ class TestIPv4Frag(VppTestCase):
             i.config_ip4()
             i.resolve_arp()
 
+    @classmethod
+    def tearDownClass(cls):
+        super(TestIPv4Frag, cls).tearDownClass()
+
     def test_frag_large_packets(self):
         """ Fragmentation of large packets """