tests: Add missing struct import
[vpp.git] / test / test_reassembly.py
index a8dc60a..e407252 100644 (file)
@@ -1,36 +1,41 @@
 #!/usr/bin/env python3
 
 import unittest
-from random import shuffle, choice, randrange
+from random import shuffle, randrange
 
-from framework import VppTestCase, VppTestRunner
+from framework import VppTestCase
+from asfframework import VppTestRunner
 
-import scapy.compat
 from scapy.packet import Raw
 from scapy.layers.l2 import Ether, GRE
-from scapy.layers.inet import IP, UDP, ICMP
-from scapy.layers.inet6 import HBHOptUnknown, ICMPv6ParamProblem,\
-    ICMPv6TimeExceeded, IPv6, IPv6ExtHdrFragment, IPv6ExtHdrHopByHop
-from framework import VppTestCase, VppTestRunner
-from util import ppp, ppc, fragment_rfc791, fragment_rfc8200
+from scapy.layers.inet import IP, UDP, ICMP, icmptypes
+from scapy.layers.inet6 import (
+    HBHOptUnknown,
+    ICMPv6ParamProblem,
+    ICMPv6TimeExceeded,
+    IPv6,
+    IPv6ExtHdrFragment,
+    IPv6ExtHdrHopByHop,
+    IPv6ExtHdrDestOpt,
+    PadN,
+    ICMPv6EchoRequest,
+    ICMPv6EchoReply,
+)
+from util import ppp, fragment_rfc791, fragment_rfc8200
 from vpp_gre_interface import VppGreInterface
-from vpp_ip import DpoProto
-from vpp_ip_route import VppIpRoute, VppRoutePath, FibPathProto
+from vpp_ip_route import VppIpRoute, VppRoutePath
 from vpp_papi import VppEnum
 
 # 35 is enough to have >257 400-byte fragments
 test_packet_count = 35
 
-# number of workers used for multi-worker test cases
-worker_count = 3
-
 
 class TestIPv4Reassembly(VppTestCase):
-    """ IPv4 Reassembly """
+    """IPv4 Reassembly"""
 
     @classmethod
     def setUpClass(cls):
-        super(TestIPv4Reassembly, cls).setUpClass()
+        super().setUpClass()
 
         cls.create_pg_interfaces([0, 1])
         cls.src_if = cls.pg0
@@ -50,23 +55,33 @@ class TestIPv4Reassembly(VppTestCase):
 
     @classmethod
     def tearDownClass(cls):
-        super(TestIPv4Reassembly, cls).tearDownClass()
+        super().tearDownClass()
 
     def setUp(self):
-        """ Test setup - force timeout on existing reassemblies """
-        super(TestIPv4Reassembly, self).setUp()
+        """Test setup - force timeout on existing reassemblies"""
+        super().setUp()
         self.vapi.ip_reassembly_enable_disable(
-            sw_if_index=self.src_if.sw_if_index, enable_ip4=True)
-        self.vapi.ip_reassembly_set(timeout_ms=0, max_reassemblies=1000,
-                                    max_reassembly_length=1000,
-                                    expire_walk_interval_ms=10)
-        self.sleep(.25)
-        self.vapi.ip_reassembly_set(timeout_ms=1000000, max_reassemblies=1000,
-                                    max_reassembly_length=1000,
-                                    expire_walk_interval_ms=10000)
+            sw_if_index=self.src_if.sw_if_index, enable_ip4=True
+        )
+        self.vapi.ip_reassembly_set(
+            timeout_ms=0,
+            max_reassemblies=1000,
+            max_reassembly_length=1000,
+            expire_walk_interval_ms=10,
+        )
+        self.virtual_sleep(0.25)
+        self.vapi.ip_reassembly_set(
+            timeout_ms=1000000,
+            max_reassemblies=1000,
+            max_reassembly_length=1000,
+            expire_walk_interval_ms=10000,
+        )
 
     def tearDown(self):
-        super(TestIPv4Reassembly, self).tearDown()
+        self.vapi.ip_reassembly_enable_disable(
+            sw_if_index=self.src_if.sw_if_index, enable_ip4=False
+        )
+        super().tearDown()
 
     def show_commands_at_teardown(self):
         self.logger.debug(self.vapi.ppcli("show ip4-full-reassembly details"))
@@ -81,11 +96,14 @@ class TestIPv4Reassembly(VppTestCase):
         for i in range(0, packet_count):
             info = cls.create_packet_info(cls.src_if, cls.src_if)
             payload = cls.info_to_payload(info)
-            p = (Ether(dst=cls.src_if.local_mac, src=cls.src_if.remote_mac) /
-                 IP(id=info.index, src=cls.src_if.remote_ip4,
-                    dst=cls.dst_if.remote_ip4) /
-                 UDP(sport=1234, dport=5678) /
-                 Raw(payload))
+            p = (
+                Ether(dst=cls.src_if.local_mac, src=cls.src_if.remote_mac)
+                / IP(
+                    id=info.index, src=cls.src_if.remote_ip4, dst=cls.dst_if.remote_ip4
+                )
+                / UDP(sport=1234, dport=5678)
+                / Raw(payload)
+            )
             size = packet_sizes[(i // 2) % len(packet_sizes)]
             cls.extend_packet(p, size, cls.padding)
             info.data = p
@@ -100,20 +118,21 @@ class TestIPv4Reassembly(VppTestCase):
             #                      p.__class__(scapy.compat.raw(p))))
             fragments_400 = fragment_rfc791(p, 400)
             fragments_300 = fragment_rfc791(p, 300)
-            fragments_200 = [
-                x for f in fragments_400 for x in fragment_rfc791(f, 200)]
-            cls.pkt_infos.append(
-                (index, fragments_400, fragments_300, fragments_200))
-        cls.fragments_400 = [
-            x for (_, frags, _, _) in cls.pkt_infos for x in frags]
-        cls.fragments_300 = [
-            x for (_, _, frags, _) in cls.pkt_infos for x in frags]
-        cls.fragments_200 = [
-            x for (_, _, _, frags) in cls.pkt_infos for x in frags]
-        cls.logger.debug("Fragmented %s packets into %s 400-byte fragments, "
-                         "%s 300-byte fragments and %s 200-byte fragments" %
-                         (len(infos), len(cls.fragments_400),
-                             len(cls.fragments_300), len(cls.fragments_200)))
+            fragments_200 = [x for f in fragments_400 for x in fragment_rfc791(f, 200)]
+            cls.pkt_infos.append((index, fragments_400, fragments_300, fragments_200))
+        cls.fragments_400 = [x for (_, frags, _, _) in cls.pkt_infos for x in frags]
+        cls.fragments_300 = [x for (_, _, frags, _) in cls.pkt_infos for x in frags]
+        cls.fragments_200 = [x for (_, _, _, frags) in cls.pkt_infos for x in frags]
+        cls.logger.debug(
+            "Fragmented %s packets into %s 400-byte fragments, "
+            "%s 300-byte fragments and %s 200-byte fragments"
+            % (
+                len(infos),
+                len(cls.fragments_400),
+                len(cls.fragments_300),
+                len(cls.fragments_200),
+            )
+        )
 
     def verify_capture(self, capture, dropped_packet_indexes=[]):
         """Verify captured packet stream.
@@ -131,7 +150,8 @@ class TestIPv4Reassembly(VppTestCase):
                 packet_index = payload_info.index
                 self.assertTrue(
                     packet_index not in dropped_packet_indexes,
-                    ppp("Packet received, but should be dropped:", packet))
+                    ppp("Packet received, but should be dropped:", packet),
+                )
                 if packet_index in seen:
                     raise Exception(ppp("Duplicate packet received", packet))
                 seen.add(packet_index)
@@ -147,11 +167,13 @@ class TestIPv4Reassembly(VppTestCase):
                 self.logger.error(ppp("Unexpected or invalid packet:", packet))
                 raise
         for index in self._packet_infos:
-            self.assertTrue(index in seen or index in dropped_packet_indexes,
-                            "Packet with packet_index %d not received" % index)
+            self.assertTrue(
+                index in seen or index in dropped_packet_indexes,
+                "Packet with packet_index %d not received" % index,
+            )
 
     def test_reassembly(self):
-        """ basic reassembly """
+        """basic reassembly"""
 
         self.pg_enable_capture()
         self.src_if.add_stream(self.fragments_200)
@@ -171,7 +193,7 @@ class TestIPv4Reassembly(VppTestCase):
         self.src_if.assert_nothing_captured()
 
     def test_verify_clear_trace_mid_reassembly(self):
-        """ verify clear trace works mid-reassembly """
+        """verify clear trace works mid-reassembly"""
 
         self.pg_enable_capture()
         self.src_if.add_stream(self.fragments_200[0:-1])
@@ -186,7 +208,7 @@ class TestIPv4Reassembly(VppTestCase):
         self.verify_capture(packets)
 
     def test_reversed(self):
-        """ reverse order reassembly """
+        """reverse order reassembly"""
 
         fragments = list(self.fragments_200)
         fragments.reverse()
@@ -209,27 +231,31 @@ class TestIPv4Reassembly(VppTestCase):
         self.src_if.assert_nothing_captured()
 
     def test_long_fragment_chain(self):
-        """ long fragment chain """
+        """long fragment chain"""
 
-        error_cnt_str = \
-            "/err/ip4-full-reassembly-feature/fragment chain too long (drop)"
+        error_cnt_str = "/err/ip4-full-reassembly-feature/reass_fragment_chain_too_long"
 
         error_cnt = self.statistics.get_err_counter(error_cnt_str)
 
-        self.vapi.ip_reassembly_set(timeout_ms=100, max_reassemblies=1000,
-                                    max_reassembly_length=3,
-                                    expire_walk_interval_ms=50)
-
-        p1 = (Ether(dst=self.src_if.local_mac, src=self.src_if.remote_mac) /
-              IP(id=1000, src=self.src_if.remote_ip4,
-                 dst=self.dst_if.remote_ip4) /
-              UDP(sport=1234, dport=5678) /
-              Raw(b"X" * 1000))
-        p2 = (Ether(dst=self.src_if.local_mac, src=self.src_if.remote_mac) /
-              IP(id=1001, src=self.src_if.remote_ip4,
-                 dst=self.dst_if.remote_ip4) /
-              UDP(sport=1234, dport=5678) /
-              Raw(b"X" * 1000))
+        self.vapi.ip_reassembly_set(
+            timeout_ms=100,
+            max_reassemblies=1000,
+            max_reassembly_length=3,
+            expire_walk_interval_ms=50,
+        )
+
+        p1 = (
+            Ether(dst=self.src_if.local_mac, src=self.src_if.remote_mac)
+            / IP(id=1000, src=self.src_if.remote_ip4, dst=self.dst_if.remote_ip4)
+            / UDP(sport=1234, dport=5678)
+            / Raw(b"X" * 1000)
+        )
+        p2 = (
+            Ether(dst=self.src_if.local_mac, src=self.src_if.remote_mac)
+            / IP(id=1001, src=self.src_if.remote_ip4, dst=self.dst_if.remote_ip4)
+            / UDP(sport=1234, dport=5678)
+            / Raw(b"X" * 1000)
+        )
         frags = fragment_rfc791(p1, 200) + fragment_rfc791(p2, 500)
 
         self.pg_enable_capture()
@@ -240,22 +266,23 @@ class TestIPv4Reassembly(VppTestCase):
         self.assert_error_counter_equal(error_cnt_str, error_cnt + 1)
 
     def test_5737(self):
-        """ fragment length + ip header size > 65535 """
+        """fragment length + ip header size > 65535"""
         self.vapi.cli("clear errors")
-        raw = b'''E\x00\x00\x88,\xf8\x1f\xfe@\x01\x98\x00\xc0\xa8\n-\xc0\xa8\n\
+        raw = b"""E\x00\x00\x88,\xf8\x1f\xfe@\x01\x98\x00\xc0\xa8\n-\xc0\xa8\n\
 \x01\x08\x00\xf0J\xed\xcb\xf1\xf5Test-group: IPv4.IPv4.ipv4-message.\
-Ethernet-Payload.IPv4-Packet.IPv4-Header.Fragment-Offset; Test-case: 5737'''
-        malformed_packet = (Ether(dst=self.src_if.local_mac,
-                                  src=self.src_if.remote_mac) /
-                            IP(raw))
-        p = (Ether(dst=self.src_if.local_mac, src=self.src_if.remote_mac) /
-             IP(id=1000, src=self.src_if.remote_ip4,
-                dst=self.dst_if.remote_ip4) /
-             UDP(sport=1234, dport=5678) /
-             Raw(b"X" * 1000))
+Ethernet-Payload.IPv4-Packet.IPv4-Header.Fragment-Offset; Test-case: 5737"""
+        malformed_packet = Ether(
+            dst=self.src_if.local_mac, src=self.src_if.remote_mac
+        ) / IP(raw)
+        p = (
+            Ether(dst=self.src_if.local_mac, src=self.src_if.remote_mac)
+            / IP(id=1000, src=self.src_if.remote_ip4, dst=self.dst_if.remote_ip4)
+            / UDP(sport=1234, dport=5678)
+            / Raw(b"X" * 1000)
+        )
         valid_fragments = fragment_rfc791(p, 400)
 
-        counter = "/err/ip4-full-reassembly-feature/malformed packets"
+        counter = "/err/ip4-full-reassembly-feature/reass_malformed_packet"
         error_counter = self.statistics.get_err_counter(counter)
         self.pg_enable_capture()
         self.src_if.add_stream([malformed_packet] + valid_fragments)
@@ -263,33 +290,50 @@ Ethernet-Payload.IPv4-Packet.IPv4-Header.Fragment-Offset; Test-case: 5737'''
 
         self.dst_if.get_capture(1)
         self.logger.debug(self.vapi.ppcli("show error"))
-        self.assertEqual(self.statistics.get_err_counter(counter),
-                         error_counter + 1)
+        self.assertEqual(self.statistics.get_err_counter(counter), error_counter + 1)
 
     def test_44924(self):
-        """ compress tiny fragments """
-        packets = [(Ether(dst=self.src_if.local_mac,
-                          src=self.src_if.remote_mac) /
-                    IP(id=24339, flags="MF", frag=0, ttl=64,
-                       src=self.src_if.remote_ip4,
-                       dst=self.dst_if.remote_ip4) /
-                    ICMP(type="echo-request", code=0, id=0x1fe6, seq=0x2407) /
-                    Raw(load='Test-group: IPv4')),
-                   (Ether(dst=self.src_if.local_mac,
-                          src=self.src_if.remote_mac) /
-                    IP(id=24339, flags="MF", frag=3, ttl=64,
-                       src=self.src_if.remote_ip4,
-                       dst=self.dst_if.remote_ip4) /
-                    ICMP(type="echo-request", code=0, id=0x1fe6, seq=0x2407) /
-                    Raw(load='.IPv4.Fragmentation.vali')),
-                   (Ether(dst=self.src_if.local_mac,
-                          src=self.src_if.remote_mac) /
-                    IP(id=24339, frag=6, ttl=64,
-                       src=self.src_if.remote_ip4,
-                       dst=self.dst_if.remote_ip4) /
-                    ICMP(type="echo-request", code=0, id=0x1fe6, seq=0x2407) /
-                    Raw(load='d; Test-case: 44924'))
-                   ]
+        """compress tiny fragments"""
+        packets = [
+            (
+                Ether(dst=self.src_if.local_mac, src=self.src_if.remote_mac)
+                / IP(
+                    id=24339,
+                    flags="MF",
+                    frag=0,
+                    ttl=64,
+                    src=self.src_if.remote_ip4,
+                    dst=self.dst_if.remote_ip4,
+                )
+                / ICMP(type="echo-request", code=0, id=0x1FE6, seq=0x2407)
+                / Raw(load="Test-group: IPv4")
+            ),
+            (
+                Ether(dst=self.src_if.local_mac, src=self.src_if.remote_mac)
+                / IP(
+                    id=24339,
+                    flags="MF",
+                    frag=3,
+                    ttl=64,
+                    src=self.src_if.remote_ip4,
+                    dst=self.dst_if.remote_ip4,
+                )
+                / ICMP(type="echo-request", code=0, id=0x1FE6, seq=0x2407)
+                / Raw(load=".IPv4.Fragmentation.vali")
+            ),
+            (
+                Ether(dst=self.src_if.local_mac, src=self.src_if.remote_mac)
+                / IP(
+                    id=24339,
+                    frag=6,
+                    ttl=64,
+                    src=self.src_if.remote_ip4,
+                    dst=self.dst_if.remote_ip4,
+                )
+                / ICMP(type="echo-request", code=0, id=0x1FE6, seq=0x2407)
+                / Raw(load="d; Test-case: 44924")
+            ),
+        ]
 
         self.pg_enable_capture()
         self.src_if.add_stream(packets)
@@ -298,27 +342,42 @@ Ethernet-Payload.IPv4-Packet.IPv4-Header.Fragment-Offset; Test-case: 5737'''
         self.dst_if.get_capture(1)
 
     def test_frag_1(self):
-        """ fragment of size 1 """
+        """fragment of size 1"""
         self.vapi.cli("clear errors")
-        malformed_packets = [(Ether(dst=self.src_if.local_mac,
-                                    src=self.src_if.remote_mac) /
-                              IP(id=7, len=21, flags="MF", frag=0, ttl=64,
-                                 src=self.src_if.remote_ip4,
-                                 dst=self.dst_if.remote_ip4) /
-                              ICMP(type="echo-request")),
-                             (Ether(dst=self.src_if.local_mac,
-                                    src=self.src_if.remote_mac) /
-                              IP(id=7, len=21, frag=1, ttl=64,
-                                 src=self.src_if.remote_ip4,
-                                 dst=self.dst_if.remote_ip4) /
-                              Raw(load=b'\x08')),
-                             ]
-
-        p = (Ether(dst=self.src_if.local_mac, src=self.src_if.remote_mac) /
-             IP(id=1000, src=self.src_if.remote_ip4,
-                dst=self.dst_if.remote_ip4) /
-             UDP(sport=1234, dport=5678) /
-             Raw(b"X" * 1000))
+        malformed_packets = [
+            (
+                Ether(dst=self.src_if.local_mac, src=self.src_if.remote_mac)
+                / IP(
+                    id=7,
+                    len=21,
+                    flags="MF",
+                    frag=0,
+                    ttl=64,
+                    src=self.src_if.remote_ip4,
+                    dst=self.dst_if.remote_ip4,
+                )
+                / ICMP(type="echo-request")
+            ),
+            (
+                Ether(dst=self.src_if.local_mac, src=self.src_if.remote_mac)
+                / IP(
+                    id=7,
+                    len=21,
+                    frag=1,
+                    ttl=64,
+                    src=self.src_if.remote_ip4,
+                    dst=self.dst_if.remote_ip4,
+                )
+                / Raw(load=b"\x08")
+            ),
+        ]
+
+        p = (
+            Ether(dst=self.src_if.local_mac, src=self.src_if.remote_mac)
+            / IP(id=1000, src=self.src_if.remote_ip4, dst=self.dst_if.remote_ip4)
+            / UDP(sport=1234, dport=5678)
+            / Raw(b"X" * 1000)
+        )
         valid_fragments = fragment_rfc791(p, 400)
 
         self.pg_enable_capture()
@@ -331,10 +390,10 @@ Ethernet-Payload.IPv4-Packet.IPv4-Header.Fragment-Offset; Test-case: 5737'''
         # TODO remove above, uncomment below once clearing of counters
         # is supported
         # self.assert_packet_counter_equal(
-        #     "/err/ip4-full-reassembly-feature/malformed packets", 1)
+        #     "/err/ip4-full-reassembly-feature/reass_malformed_packet", 1)
 
     def test_random(self):
-        """ random order reassembly """
+        """random order reassembly"""
 
         fragments = list(self.fragments_200)
         shuffle(fragments)
@@ -357,10 +416,11 @@ Ethernet-Payload.IPv4-Packet.IPv4-Header.Fragment-Offset; Test-case: 5737'''
         self.src_if.assert_nothing_captured()
 
     def test_duplicates(self):
-        """ duplicate fragments """
+        """duplicate fragments"""
 
         fragments = [
-            x for (_, frags, _, _) in self.pkt_infos
+            x
+            for (_, frags, _, _) in self.pkt_infos
             for x in frags
             for _ in range(0, min(2, len(frags)))
         ]
@@ -374,7 +434,7 @@ Ethernet-Payload.IPv4-Packet.IPv4-Header.Fragment-Offset; Test-case: 5737'''
         self.src_if.assert_nothing_captured()
 
     def test_overlap1(self):
-        """ overlapping fragments case #1 """
+        """overlapping fragments case #1"""
 
         fragments = []
         for _, _, frags_300, frags_200 in self.pkt_infos:
@@ -403,7 +463,7 @@ Ethernet-Payload.IPv4-Packet.IPv4-Header.Fragment-Offset; Test-case: 5737'''
         self.src_if.assert_nothing_captured()
 
     def test_overlap2(self):
-        """ overlapping fragments case #2 """
+        """overlapping fragments case #2"""
 
         fragments = []
         for _, _, frags_300, frags_200 in self.pkt_infos:
@@ -438,88 +498,124 @@ Ethernet-Payload.IPv4-Packet.IPv4-Header.Fragment-Offset; Test-case: 5737'''
         self.src_if.assert_nothing_captured()
 
     def test_timeout_inline(self):
-        """ timeout (inline) """
+        """timeout (inline)"""
 
         dropped_packet_indexes = set(
             index for (index, frags, _, _) in self.pkt_infos if len(frags) > 1
         )
 
-        self.vapi.ip_reassembly_set(timeout_ms=0, max_reassemblies=1000,
-                                    max_reassembly_length=3,
-                                    expire_walk_interval_ms=10000)
+        self.vapi.ip_reassembly_set(
+            timeout_ms=0,
+            max_reassemblies=1000,
+            max_reassembly_length=3,
+            expire_walk_interval_ms=10000,
+        )
 
         self.pg_enable_capture()
         self.src_if.add_stream(self.fragments_400)
         self.pg_start()
 
         packets = self.dst_if.get_capture(
-            len(self.pkt_infos) - len(dropped_packet_indexes))
+            len(self.pkt_infos) - len(dropped_packet_indexes)
+        )
         self.verify_capture(packets, dropped_packet_indexes)
         self.src_if.assert_nothing_captured()
 
     def test_timeout_cleanup(self):
-        """ timeout (cleanup) """
+        """timeout (cleanup)"""
 
         # whole packets + fragmented packets sans last fragment
         fragments = [
-            x for (_, frags_400, _, _) in self.pkt_infos
-            for x in frags_400[:-1 if len(frags_400) > 1 else None]
+            x
+            for (_, frags_400, _, _) in self.pkt_infos
+            for x in frags_400[: -1 if len(frags_400) > 1 else None]
         ]
 
         # last fragments for fragmented packets
-        fragments2 = [frags_400[-1]
-                      for (_, frags_400, _, _) in self.pkt_infos
-                      if len(frags_400) > 1]
+        fragments2 = [
+            frags_400[-1]
+            for (_, frags_400, _, _) in self.pkt_infos
+            if len(frags_400) > 1
+        ]
 
         dropped_packet_indexes = set(
-            index for (index, frags_400, _, _) in self.pkt_infos
-            if len(frags_400) > 1)
+            index for (index, frags_400, _, _) in self.pkt_infos if len(frags_400) > 1
+        )
 
-        self.vapi.ip_reassembly_set(timeout_ms=100, max_reassemblies=1000,
-                                    max_reassembly_length=1000,
-                                    expire_walk_interval_ms=50)
+        self.vapi.ip_reassembly_set(
+            timeout_ms=100,
+            max_reassemblies=1000,
+            max_reassembly_length=1000,
+            expire_walk_interval_ms=50,
+        )
 
         self.pg_enable_capture()
         self.src_if.add_stream(fragments)
         self.pg_start()
 
-        self.sleep(.25, "wait before sending rest of fragments")
+        self.virtual_sleep(0.25, "wait before sending rest of fragments")
 
         self.src_if.add_stream(fragments2)
         self.pg_start()
 
         packets = self.dst_if.get_capture(
-            len(self.pkt_infos) - len(dropped_packet_indexes))
+            len(self.pkt_infos) - len(dropped_packet_indexes)
+        )
         self.verify_capture(packets, dropped_packet_indexes)
         self.src_if.assert_nothing_captured()
 
     def test_disabled(self):
-        """ reassembly disabled """
+        """reassembly disabled"""
 
         dropped_packet_indexes = set(
-            index for (index, frags_400, _, _) in self.pkt_infos
-            if len(frags_400) > 1)
+            index for (index, frags_400, _, _) in self.pkt_infos if len(frags_400) > 1
+        )
 
-        self.vapi.ip_reassembly_set(timeout_ms=1000, max_reassemblies=0,
-                                    max_reassembly_length=3,
-                                    expire_walk_interval_ms=10000)
+        self.vapi.ip_reassembly_set(
+            timeout_ms=1000,
+            max_reassemblies=0,
+            max_reassembly_length=3,
+            expire_walk_interval_ms=10000,
+        )
 
         self.pg_enable_capture()
         self.src_if.add_stream(self.fragments_400)
         self.pg_start()
 
         packets = self.dst_if.get_capture(
-            len(self.pkt_infos) - len(dropped_packet_indexes))
+            len(self.pkt_infos) - len(dropped_packet_indexes)
+        )
         self.verify_capture(packets, dropped_packet_indexes)
         self.src_if.assert_nothing_captured()
 
+    def test_local_enable_disable(self):
+        """local reassembly enabled/disable"""
+        self.vapi.ip_reassembly_enable_disable(
+            sw_if_index=self.src_if.sw_if_index, enable_ip4=False
+        )
+        self.vapi.ip_local_reass_enable_disable(enable_ip4=True)
+        p = (
+            Ether(src=self.src_if.remote_mac, dst=self.src_if.local_mac)
+            / IP(src=self.src_if.remote_ip4, dst=self.src_if.local_ip4)
+            / ICMP(id=1234, type="echo-request")
+            / Raw("x" * 1000)
+        )
+        frags = fragment_rfc791(p, 400)
+        r = self.send_and_expect(self.src_if, frags, self.src_if, n_rx=1)[0]
+        self.assertEqual(1234, r[ICMP].id)
+        self.assertEqual(icmptypes[r[ICMP].type], "echo-reply")
+        self.vapi.ip_local_reass_enable_disable()
+
+        self.send_and_assert_no_replies(self.src_if, frags)
+        self.vapi.ip_local_reass_enable_disable(enable_ip4=True)
+
 
 class TestIPv4SVReassembly(VppTestCase):
-    """ IPv4 Shallow Virtual Reassembly """
+    """IPv4 Shallow Virtual Reassembly"""
 
     @classmethod
     def setUpClass(cls):
-        super(TestIPv4SVReassembly, cls).setUpClass()
+        super().setUpClass()
 
         cls.create_pg_interfaces([0, 1])
         cls.src_if = cls.pg0
@@ -532,30 +628,36 @@ class TestIPv4SVReassembly(VppTestCase):
             i.resolve_arp()
 
     def setUp(self):
-        """ Test setup - force timeout on existing reassemblies """
-        super(TestIPv4SVReassembly, self).setUp()
+        """Test setup - force timeout on existing reassemblies"""
+        super().setUp()
         self.vapi.ip_reassembly_enable_disable(
-            sw_if_index=self.src_if.sw_if_index, enable_ip4=True,
-            type=VppEnum.vl_api_ip_reass_type_t.IP_REASS_TYPE_SHALLOW_VIRTUAL)
+            sw_if_index=self.src_if.sw_if_index,
+            enable_ip4=True,
+            type=VppEnum.vl_api_ip_reass_type_t.IP_REASS_TYPE_SHALLOW_VIRTUAL,
+        )
         self.vapi.ip_reassembly_set(
-            timeout_ms=0, max_reassemblies=1000,
+            timeout_ms=0,
+            max_reassemblies=1000,
             max_reassembly_length=1000,
             type=VppEnum.vl_api_ip_reass_type_t.IP_REASS_TYPE_SHALLOW_VIRTUAL,
-            expire_walk_interval_ms=10)
-        self.sleep(.25)
+            expire_walk_interval_ms=10,
+        )
+        self.virtual_sleep(0.25)
         self.vapi.ip_reassembly_set(
-            timeout_ms=1000000, max_reassemblies=1000,
+            timeout_ms=1000000,
+            max_reassemblies=1000,
             max_reassembly_length=1000,
             type=VppEnum.vl_api_ip_reass_type_t.IP_REASS_TYPE_SHALLOW_VIRTUAL,
-            expire_walk_interval_ms=10000)
+            expire_walk_interval_ms=10000,
+        )
 
     def tearDown(self):
-        super(TestIPv4SVReassembly, self).tearDown()
+        super().tearDown()
         self.logger.debug(self.vapi.ppcli("show ip4-sv-reassembly details"))
         self.logger.debug(self.vapi.ppcli("show buffers"))
 
     def test_basic(self):
-        """ basic reassembly """
+        """basic reassembly"""
         payload_len = 1000
         payload = ""
         counter = 0
@@ -563,12 +665,13 @@ class TestIPv4SVReassembly(VppTestCase):
             payload += "%u " % counter
             counter += 1
 
-        p = (Ether(dst=self.src_if.local_mac, src=self.src_if.remote_mac) /
-             IP(id=1, src=self.src_if.remote_ip4,
-                dst=self.dst_if.remote_ip4) /
-             UDP(sport=1234, dport=5678) /
-             Raw(payload))
-        fragments = fragment_rfc791(p, payload_len/4)
+        p = (
+            Ether(dst=self.src_if.local_mac, src=self.src_if.remote_mac)
+            / IP(id=1, src=self.src_if.remote_ip4, dst=self.dst_if.remote_ip4)
+            / UDP(sport=1234, dport=5678)
+            / Raw(payload)
+        )
+        fragments = fragment_rfc791(p, payload_len / 4)
 
         # send fragment #2 - should be cached inside reassembly
         self.pg_enable_capture()
@@ -604,7 +707,7 @@ class TestIPv4SVReassembly(VppTestCase):
             self.assertEqual(sent[Raw].payload, recvd[Raw].payload)
 
     def test_verify_clear_trace_mid_reassembly(self):
-        """ verify clear trace works mid-reassembly """
+        """verify clear trace works mid-reassembly"""
         payload_len = 1000
         payload = ""
         counter = 0
@@ -612,12 +715,13 @@ class TestIPv4SVReassembly(VppTestCase):
             payload += "%u " % counter
             counter += 1
 
-        p = (Ether(dst=self.src_if.local_mac, src=self.src_if.remote_mac) /
-             IP(id=1, src=self.src_if.remote_ip4,
-                dst=self.dst_if.remote_ip4) /
-             UDP(sport=1234, dport=5678) /
-             Raw(payload))
-        fragments = fragment_rfc791(p, payload_len/4)
+        p = (
+            Ether(dst=self.src_if.local_mac, src=self.src_if.remote_mac)
+            / IP(id=1, src=self.src_if.remote_ip4, dst=self.dst_if.remote_ip4)
+            / UDP(sport=1234, dport=5678)
+            / Raw(payload)
+        )
+        fragments = fragment_rfc791(p, payload_len / 4)
 
         self.pg_enable_capture()
         self.src_if.add_stream(fragments[1])
@@ -640,7 +744,7 @@ class TestIPv4SVReassembly(VppTestCase):
         self.dst_if.get_capture(len(fragments[2:]))
 
     def test_timeout(self):
-        """ reassembly timeout """
+        """reassembly timeout"""
         payload_len = 1000
         payload = ""
         counter = 0
@@ -648,18 +752,21 @@ class TestIPv4SVReassembly(VppTestCase):
             payload += "%u " % counter
             counter += 1
 
-        p = (Ether(dst=self.src_if.local_mac, src=self.src_if.remote_mac) /
-             IP(id=1, src=self.src_if.remote_ip4,
-                dst=self.dst_if.remote_ip4) /
-             UDP(sport=1234, dport=5678) /
-             Raw(payload))
-        fragments = fragment_rfc791(p, payload_len/4)
+        p = (
+            Ether(dst=self.src_if.local_mac, src=self.src_if.remote_mac)
+            / IP(id=1, src=self.src_if.remote_ip4, dst=self.dst_if.remote_ip4)
+            / UDP(sport=1234, dport=5678)
+            / Raw(payload)
+        )
+        fragments = fragment_rfc791(p, payload_len / 4)
 
         self.vapi.ip_reassembly_set(
-            timeout_ms=100, max_reassemblies=1000,
+            timeout_ms=100,
+            max_reassemblies=1000,
             max_reassembly_length=1000,
             expire_walk_interval_ms=50,
-            type=VppEnum.vl_api_ip_reass_type_t.IP_REASS_TYPE_SHALLOW_VIRTUAL)
+            type=VppEnum.vl_api_ip_reass_type_t.IP_REASS_TYPE_SHALLOW_VIRTUAL,
+        )
 
         # send fragments #2 and #1 - should be forwarded
         self.pg_enable_capture()
@@ -675,7 +782,7 @@ class TestIPv4SVReassembly(VppTestCase):
             self.assertEqual(sent[Raw].payload, recvd[Raw].payload)
 
         # wait for cleanup
-        self.sleep(.25, "wait before sending rest of fragments")
+        self.virtual_sleep(0.25, "wait before sending rest of fragments")
 
         # send rest of fragments - shouldn't be forwarded
         self.pg_enable_capture()
@@ -684,13 +791,15 @@ class TestIPv4SVReassembly(VppTestCase):
         self.dst_if.assert_nothing_captured()
 
     def test_lru(self):
-        """ reassembly reuses LRU element """
+        """reassembly reuses LRU element"""
 
         self.vapi.ip_reassembly_set(
-            timeout_ms=1000000, max_reassemblies=1,
+            timeout_ms=1000000,
+            max_reassemblies=1,
             max_reassembly_length=1000,
             type=VppEnum.vl_api_ip_reass_type_t.IP_REASS_TYPE_SHALLOW_VIRTUAL,
-            expire_walk_interval_ms=10000)
+            expire_walk_interval_ms=10000,
+        )
 
         payload_len = 1000
         payload = ""
@@ -701,15 +810,17 @@ class TestIPv4SVReassembly(VppTestCase):
 
         packet_count = 10
 
-        fragments = [f
-                     for i in range(packet_count)
-                     for p in (Ether(dst=self.src_if.local_mac,
-                                     src=self.src_if.remote_mac) /
-                               IP(id=i, src=self.src_if.remote_ip4,
-                                   dst=self.dst_if.remote_ip4) /
-                               UDP(sport=1234, dport=5678) /
-                               Raw(payload))
-                     for f in fragment_rfc791(p, payload_len/4)]
+        fragments = [
+            f
+            for i in range(packet_count)
+            for p in (
+                Ether(dst=self.src_if.local_mac, src=self.src_if.remote_mac)
+                / IP(id=i, src=self.src_if.remote_ip4, dst=self.dst_if.remote_ip4)
+                / UDP(sport=1234, dport=5678)
+                / Raw(payload)
+            )
+            for f in fragment_rfc791(p, payload_len / 4)
+        ]
 
         self.pg_enable_capture()
         self.src_if.add_stream(fragments)
@@ -723,16 +834,20 @@ class TestIPv4SVReassembly(VppTestCase):
     def send_mixed_and_verify_capture(self, traffic):
         stream = []
         for t in traffic:
-            for c in range(t['count']):
+            for c in range(t["count"]):
                 stream.append(
-                    (Ether(dst=self.src_if.local_mac,
-                           src=self.src_if.remote_mac) /
-                     IP(id=self.counter,
-                        flags=t['flags'],
-                        src=self.src_if.remote_ip4,
-                        dst=self.dst_if.remote_ip4) /
-                     UDP(sport=1234, dport=5678) /
-                     Raw("abcdef")))
+                    (
+                        Ether(dst=self.src_if.local_mac, src=self.src_if.remote_mac)
+                        / IP(
+                            id=self.counter,
+                            flags=t["flags"],
+                            src=self.src_if.remote_ip4,
+                            dst=self.dst_if.remote_ip4,
+                        )
+                        / UDP(sport=1234, dport=5678)
+                        / Raw("abcdef")
+                    )
+                )
                 self.counter = self.counter + 1
 
         self.pg_enable_capture()
@@ -744,58 +859,89 @@ class TestIPv4SVReassembly(VppTestCase):
         self.dst_if.get_capture(len(stream))
 
     def test_mixed(self):
-        """ mixed traffic correctly passes through SVR """
+        """mixed traffic correctly passes through SVR"""
         self.counter = 1
 
-        self.send_mixed_and_verify_capture([{'count': 1, 'flags': ''}])
-        self.send_mixed_and_verify_capture([{'count': 2, 'flags': ''}])
-        self.send_mixed_and_verify_capture([{'count': 3, 'flags': ''}])
-        self.send_mixed_and_verify_capture([{'count': 8, 'flags': ''}])
-        self.send_mixed_and_verify_capture([{'count': 257, 'flags': ''}])
+        self.send_mixed_and_verify_capture([{"count": 1, "flags": ""}])
+        self.send_mixed_and_verify_capture([{"count": 2, "flags": ""}])
+        self.send_mixed_and_verify_capture([{"count": 3, "flags": ""}])
+        self.send_mixed_and_verify_capture([{"count": 8, "flags": ""}])
+        self.send_mixed_and_verify_capture([{"count": 257, "flags": ""}])
 
-        self.send_mixed_and_verify_capture([{'count': 1, 'flags': 'MF'}])
-        self.send_mixed_and_verify_capture([{'count': 2, 'flags': 'MF'}])
-        self.send_mixed_and_verify_capture([{'count': 3, 'flags': 'MF'}])
-        self.send_mixed_and_verify_capture([{'count': 8, 'flags': 'MF'}])
-        self.send_mixed_and_verify_capture([{'count': 257, 'flags': 'MF'}])
+        self.send_mixed_and_verify_capture([{"count": 1, "flags": "MF"}])
+        self.send_mixed_and_verify_capture([{"count": 2, "flags": "MF"}])
+        self.send_mixed_and_verify_capture([{"count": 3, "flags": "MF"}])
+        self.send_mixed_and_verify_capture([{"count": 8, "flags": "MF"}])
+        self.send_mixed_and_verify_capture([{"count": 257, "flags": "MF"}])
 
         self.send_mixed_and_verify_capture(
-            [{'count': 1, 'flags': ''}, {'count': 1, 'flags': 'MF'}])
+            [{"count": 1, "flags": ""}, {"count": 1, "flags": "MF"}]
+        )
         self.send_mixed_and_verify_capture(
-            [{'count': 2, 'flags': ''}, {'count': 2, 'flags': 'MF'}])
+            [{"count": 2, "flags": ""}, {"count": 2, "flags": "MF"}]
+        )
         self.send_mixed_and_verify_capture(
-            [{'count': 3, 'flags': ''}, {'count': 3, 'flags': 'MF'}])
+            [{"count": 3, "flags": ""}, {"count": 3, "flags": "MF"}]
+        )
         self.send_mixed_and_verify_capture(
-            [{'count': 8, 'flags': ''}, {'count': 8, 'flags': 'MF'}])
+            [{"count": 8, "flags": ""}, {"count": 8, "flags": "MF"}]
+        )
         self.send_mixed_and_verify_capture(
-            [{'count': 129, 'flags': ''}, {'count': 129, 'flags': 'MF'}])
+            [{"count": 129, "flags": ""}, {"count": 129, "flags": "MF"}]
+        )
 
         self.send_mixed_and_verify_capture(
-            [{'count': 1, 'flags': ''}, {'count': 1, 'flags': 'MF'},
-             {'count': 1, 'flags': ''}, {'count': 1, 'flags': 'MF'}])
+            [
+                {"count": 1, "flags": ""},
+                {"count": 1, "flags": "MF"},
+                {"count": 1, "flags": ""},
+                {"count": 1, "flags": "MF"},
+            ]
+        )
         self.send_mixed_and_verify_capture(
-            [{'count': 2, 'flags': ''}, {'count': 2, 'flags': 'MF'},
-             {'count': 2, 'flags': ''}, {'count': 2, 'flags': 'MF'}])
+            [
+                {"count": 2, "flags": ""},
+                {"count": 2, "flags": "MF"},
+                {"count": 2, "flags": ""},
+                {"count": 2, "flags": "MF"},
+            ]
+        )
         self.send_mixed_and_verify_capture(
-            [{'count': 3, 'flags': ''}, {'count': 3, 'flags': 'MF'},
-             {'count': 3, 'flags': ''}, {'count': 3, 'flags': 'MF'}])
+            [
+                {"count": 3, "flags": ""},
+                {"count": 3, "flags": "MF"},
+                {"count": 3, "flags": ""},
+                {"count": 3, "flags": "MF"},
+            ]
+        )
         self.send_mixed_and_verify_capture(
-            [{'count': 8, 'flags': ''}, {'count': 8, 'flags': 'MF'},
-             {'count': 8, 'flags': ''}, {'count': 8, 'flags': 'MF'}])
+            [
+                {"count": 8, "flags": ""},
+                {"count": 8, "flags": "MF"},
+                {"count": 8, "flags": ""},
+                {"count": 8, "flags": "MF"},
+            ]
+        )
         self.send_mixed_and_verify_capture(
-            [{'count': 65, 'flags': ''}, {'count': 65, 'flags': 'MF'},
-             {'count': 65, 'flags': ''}, {'count': 65, 'flags': 'MF'}])
+            [
+                {"count": 65, "flags": ""},
+                {"count": 65, "flags": "MF"},
+                {"count": 65, "flags": ""},
+                {"count": 65, "flags": "MF"},
+            ]
+        )
 
 
 class TestIPv4MWReassembly(VppTestCase):
-    """ IPv4 Reassembly (multiple workers) """
-    worker_config = "workers %d" % worker_count
+    """IPv4 Reassembly (multiple workers)"""
+
+    vpp_worker_count = 3
 
     @classmethod
     def setUpClass(cls):
-        super(TestIPv4MWReassembly, cls).setUpClass()
+        super().setUpClass()
 
-        cls.create_pg_interfaces(range(worker_count+1))
+        cls.create_pg_interfaces(range(cls.vpp_worker_count + 1))
         cls.src_if = cls.pg0
         cls.send_ifs = cls.pg_interfaces[:-1]
         cls.dst_if = cls.pg_interfaces[-1]
@@ -809,32 +955,47 @@ class TestIPv4MWReassembly(VppTestCase):
         # packets sizes reduced here because we are generating packets without
         # Ethernet headers, which are added later (diff fragments go via
         # different interfaces)
-        cls.packet_sizes = [64-len(Ether()), 512-len(Ether()),
-                            1518-len(Ether()), 9018-len(Ether())]
+        cls.packet_sizes = [
+            64 - len(Ether()),
+            512 - len(Ether()),
+            1518 - len(Ether()),
+            9018 - len(Ether()),
+        ]
         cls.padding = " abcdefghijklmn"
         cls.create_stream(cls.packet_sizes)
         cls.create_fragments()
 
     @classmethod
     def tearDownClass(cls):
-        super(TestIPv4MWReassembly, cls).tearDownClass()
+        super().tearDownClass()
 
     def setUp(self):
-        """ Test setup - force timeout on existing reassemblies """
-        super(TestIPv4MWReassembly, self).setUp()
+        """Test setup - force timeout on existing reassemblies"""
+        super().setUp()
         for intf in self.send_ifs:
             self.vapi.ip_reassembly_enable_disable(
-                sw_if_index=intf.sw_if_index, enable_ip4=True)
-        self.vapi.ip_reassembly_set(timeout_ms=0, max_reassemblies=1000,
-                                    max_reassembly_length=1000,
-                                    expire_walk_interval_ms=10)
-        self.sleep(.25)
-        self.vapi.ip_reassembly_set(timeout_ms=1000000, max_reassemblies=1000,
-                                    max_reassembly_length=1000,
-                                    expire_walk_interval_ms=10000)
+                sw_if_index=intf.sw_if_index, enable_ip4=True
+            )
+        self.vapi.ip_reassembly_set(
+            timeout_ms=0,
+            max_reassemblies=1000,
+            max_reassembly_length=1000,
+            expire_walk_interval_ms=10,
+        )
+        self.virtual_sleep(0.25)
+        self.vapi.ip_reassembly_set(
+            timeout_ms=1000000,
+            max_reassemblies=1000,
+            max_reassembly_length=1000,
+            expire_walk_interval_ms=10000,
+        )
 
     def tearDown(self):
-        super(TestIPv4MWReassembly, self).tearDown()
+        for intf in self.send_ifs:
+            self.vapi.ip_reassembly_enable_disable(
+                sw_if_index=intf.sw_if_index, enable_ip4=False
+            )
+        super().tearDown()
 
     def show_commands_at_teardown(self):
         self.logger.debug(self.vapi.ppcli("show ip4-full-reassembly details"))
@@ -849,10 +1010,11 @@ class TestIPv4MWReassembly(VppTestCase):
         for i in range(0, packet_count):
             info = cls.create_packet_info(cls.src_if, cls.src_if)
             payload = cls.info_to_payload(info)
-            p = (IP(id=info.index, src=cls.src_if.remote_ip4,
-                    dst=cls.dst_if.remote_ip4) /
-                 UDP(sport=1234, dport=5678) /
-                 Raw(payload))
+            p = (
+                IP(id=info.index, src=cls.src_if.remote_ip4, dst=cls.dst_if.remote_ip4)
+                / UDP(sport=1234, dport=5678)
+                / Raw(payload)
+            )
             size = packet_sizes[(i // 2) % len(packet_sizes)]
             cls.extend_packet(p, size, cls.padding)
             info.data = p
@@ -867,10 +1029,11 @@ class TestIPv4MWReassembly(VppTestCase):
             #                      p.__class__(scapy.compat.raw(p))))
             fragments_400 = fragment_rfc791(p, 400)
             cls.pkt_infos.append((index, fragments_400))
-        cls.fragments_400 = [
-            x for (_, frags) in cls.pkt_infos for x in frags]
-        cls.logger.debug("Fragmented %s packets into %s 400-byte fragments, " %
-                         (len(infos), len(cls.fragments_400)))
+        cls.fragments_400 = [x for (_, frags) in cls.pkt_infos for x in frags]
+        cls.logger.debug(
+            "Fragmented %s packets into %s 400-byte fragments, "
+            % (len(infos), len(cls.fragments_400))
+        )
 
     def verify_capture(self, capture, dropped_packet_indexes=[]):
         """Verify captured packet stream.
@@ -888,7 +1051,8 @@ class TestIPv4MWReassembly(VppTestCase):
                 packet_index = payload_info.index
                 self.assertTrue(
                     packet_index not in dropped_packet_indexes,
-                    ppp("Packet received, but should be dropped:", packet))
+                    ppp("Packet received, but should be dropped:", packet),
+                )
                 if packet_index in seen:
                     raise Exception(ppp("Duplicate packet received", packet))
                 seen.add(packet_index)
@@ -904,39 +1068,44 @@ class TestIPv4MWReassembly(VppTestCase):
                 self.logger.error(ppp("Unexpected or invalid packet:", packet))
                 raise
         for index in self._packet_infos:
-            self.assertTrue(index in seen or index in dropped_packet_indexes,
-                            "Packet with packet_index %d not received" % index)
+            self.assertTrue(
+                index in seen or index in dropped_packet_indexes,
+                "Packet with packet_index %d not received" % index,
+            )
 
     def send_packets(self, packets):
-        for counter in range(worker_count):
+        for counter in range(self.vpp_worker_count):
             if 0 == len(packets[counter]):
                 continue
             send_if = self.send_ifs[counter]
             send_if.add_stream(
-                (Ether(dst=send_if.local_mac, src=send_if.remote_mac) / x
-                 for x in packets[counter]),
-                worker=counter)
+                (
+                    Ether(dst=send_if.local_mac, src=send_if.remote_mac) / x
+                    for x in packets[counter]
+                ),
+                worker=counter,
+            )
         self.pg_start()
 
     def test_worker_conflict(self):
-        """ 1st and FO=0 fragments on different workers """
+        """1st and FO=0 fragments on different workers"""
 
         # in first wave we send fragments which don't start at offset 0
         # then we send fragments with offset 0 on a different thread
         # then the rest of packets on a random thread
-        first_packets = [[] for n in range(worker_count)]
-        second_packets = [[] for n in range(worker_count)]
-        rest_of_packets = [[] for n in range(worker_count)]
-        for (_, p) in self.pkt_infos:
-            wi = randrange(worker_count)
+        first_packets = [[] for n in range(self.vpp_worker_count)]
+        second_packets = [[] for n in range(self.vpp_worker_count)]
+        rest_of_packets = [[] for n in range(self.vpp_worker_count)]
+        for _, p in self.pkt_infos:
+            wi = randrange(self.vpp_worker_count)
             second_packets[wi].append(p[0])
             if len(p) <= 1:
                 continue
             wi2 = wi
             while wi2 == wi:
-                wi2 = randrange(worker_count)
+                wi2 = randrange(self.vpp_worker_count)
             first_packets[wi2].append(p[1])
-            wi3 = randrange(worker_count)
+            wi3 = randrange(self.vpp_worker_count)
             rest_of_packets[wi3].extend(p[2:])
 
         self.pg_enable_capture()
@@ -966,11 +1135,11 @@ class TestIPv4MWReassembly(VppTestCase):
 
 
 class TestIPv6Reassembly(VppTestCase):
-    """ IPv6 Reassembly """
+    """IPv6 Reassembly"""
 
     @classmethod
     def setUpClass(cls):
-        super(TestIPv6Reassembly, cls).setUpClass()
+        super().setUpClass()
 
         cls.create_pg_interfaces([0, 1])
         cls.src_if = cls.pg0
@@ -990,25 +1159,37 @@ class TestIPv6Reassembly(VppTestCase):
 
     @classmethod
     def tearDownClass(cls):
-        super(TestIPv6Reassembly, cls).tearDownClass()
+        super().tearDownClass()
 
     def setUp(self):
-        """ Test setup - force timeout on existing reassemblies """
-        super(TestIPv6Reassembly, self).setUp()
+        """Test setup - force timeout on existing reassemblies"""
+        super().setUp()
         self.vapi.ip_reassembly_enable_disable(
-            sw_if_index=self.src_if.sw_if_index, enable_ip6=True)
-        self.vapi.ip_reassembly_set(timeout_ms=0, max_reassemblies=1000,
-                                    max_reassembly_length=1000,
-                                    expire_walk_interval_ms=10, is_ip6=1)
-        self.sleep(.25)
-        self.vapi.ip_reassembly_set(timeout_ms=1000000, max_reassemblies=1000,
-                                    max_reassembly_length=1000,
-                                    expire_walk_interval_ms=10000, is_ip6=1)
+            sw_if_index=self.src_if.sw_if_index, enable_ip6=True
+        )
+        self.vapi.ip_reassembly_set(
+            timeout_ms=0,
+            max_reassemblies=1000,
+            max_reassembly_length=1000,
+            expire_walk_interval_ms=10,
+            is_ip6=1,
+        )
+        self.virtual_sleep(0.25)
+        self.vapi.ip_reassembly_set(
+            timeout_ms=1000000,
+            max_reassemblies=1000,
+            max_reassembly_length=1000,
+            expire_walk_interval_ms=10000,
+            is_ip6=1,
+        )
         self.logger.debug(self.vapi.ppcli("show ip6-full-reassembly details"))
         self.logger.debug(self.vapi.ppcli("show buffers"))
 
     def tearDown(self):
-        super(TestIPv6Reassembly, self).tearDown()
+        self.vapi.ip_reassembly_enable_disable(
+            sw_if_index=self.src_if.sw_if_index, enable_ip6=False
+        )
+        super().tearDown()
 
     def show_commands_at_teardown(self):
         self.logger.debug(self.vapi.ppcli("show ip6-full-reassembly details"))
@@ -1023,11 +1204,12 @@ class TestIPv6Reassembly(VppTestCase):
         for i in range(0, packet_count):
             info = cls.create_packet_info(cls.src_if, cls.src_if)
             payload = cls.info_to_payload(info)
-            p = (Ether(dst=cls.src_if.local_mac, src=cls.src_if.remote_mac) /
-                 IPv6(src=cls.src_if.remote_ip6,
-                      dst=cls.dst_if.remote_ip6) /
-                 UDP(sport=1234, dport=5678) /
-                 Raw(payload))
+            p = (
+                Ether(dst=cls.src_if.local_mac, src=cls.src_if.remote_mac)
+                / IPv6(src=cls.src_if.remote_ip6, dst=cls.dst_if.remote_ip6)
+                / UDP(sport=1234, dport=5678)
+                / Raw(payload)
+            )
             size = packet_sizes[(i // 2) % len(packet_sizes)]
             cls.extend_packet(p, size, cls.padding)
             info.data = p
@@ -1043,14 +1225,13 @@ class TestIPv6Reassembly(VppTestCase):
             fragments_400 = fragment_rfc8200(p, info.index, 400)
             fragments_300 = fragment_rfc8200(p, info.index, 300)
             cls.pkt_infos.append((index, fragments_400, fragments_300))
-        cls.fragments_400 = [
-            x for _, frags, _ in cls.pkt_infos for x in frags]
-        cls.fragments_300 = [
-            x for _, _, frags in cls.pkt_infos for x in frags]
-        cls.logger.debug("Fragmented %s packets into %s 400-byte fragments, "
-                         "and %s 300-byte fragments" %
-                         (len(infos), len(cls.fragments_400),
-                             len(cls.fragments_300)))
+        cls.fragments_400 = [x for _, frags, _ in cls.pkt_infos for x in frags]
+        cls.fragments_300 = [x for _, _, frags in cls.pkt_infos for x in frags]
+        cls.logger.debug(
+            "Fragmented %s packets into %s 400-byte fragments, "
+            "and %s 300-byte fragments"
+            % (len(infos), len(cls.fragments_400), len(cls.fragments_300))
+        )
 
     def verify_capture(self, capture, dropped_packet_indexes=[]):
         """Verify captured packet strea .
@@ -1068,7 +1249,8 @@ class TestIPv6Reassembly(VppTestCase):
                 packet_index = payload_info.index
                 self.assertTrue(
                     packet_index not in dropped_packet_indexes,
-                    ppp("Packet received, but should be dropped:", packet))
+                    ppp("Packet received, but should be dropped:", packet),
+                )
                 if packet_index in seen:
                     raise Exception(ppp("Duplicate packet received", packet))
                 seen.add(packet_index)
@@ -1084,11 +1266,13 @@ class TestIPv6Reassembly(VppTestCase):
                 self.logger.error(ppp("Unexpected or invalid packet:", packet))
                 raise
         for index in self._packet_infos:
-            self.assertTrue(index in seen or index in dropped_packet_indexes,
-                            "Packet with packet_index %d not received" % index)
+            self.assertTrue(
+                index in seen or index in dropped_packet_indexes,
+                "Packet with packet_index %d not received" % index,
+            )
 
     def test_reassembly(self):
-        """ basic reassembly """
+        """basic reassembly"""
 
         self.pg_enable_capture()
         self.src_if.add_stream(self.fragments_400)
@@ -1108,16 +1292,16 @@ class TestIPv6Reassembly(VppTestCase):
         self.src_if.assert_nothing_captured()
 
     def test_buffer_boundary(self):
-        """ fragment header crossing buffer boundary """
-
-        p = (Ether(dst=self.src_if.local_mac, src=self.src_if.remote_mac) /
-             IPv6(src=self.src_if.remote_ip6,
-                  dst=self.src_if.local_ip6) /
-             IPv6ExtHdrHopByHop(
-                 options=[HBHOptUnknown(otype=0xff, optlen=0)] * 1000) /
-             IPv6ExtHdrFragment(m=1) /
-             UDP(sport=1234, dport=5678) /
-             Raw())
+        """fragment header crossing buffer boundary"""
+
+        p = (
+            Ether(dst=self.src_if.local_mac, src=self.src_if.remote_mac)
+            / IPv6(src=self.src_if.remote_ip6, dst=self.src_if.local_ip6)
+            / IPv6ExtHdrHopByHop(options=[HBHOptUnknown(otype=0xFF, optlen=0)] * 1000)
+            / IPv6ExtHdrFragment(m=1)
+            / UDP(sport=1234, dport=5678)
+            / Raw()
+        )
         self.pg_enable_capture()
         self.src_if.add_stream([p])
         self.pg_start()
@@ -1125,7 +1309,7 @@ class TestIPv6Reassembly(VppTestCase):
         self.dst_if.assert_nothing_captured()
 
     def test_verify_clear_trace_mid_reassembly(self):
-        """ verify clear trace works mid-reassembly """
+        """verify clear trace works mid-reassembly"""
 
         self.pg_enable_capture()
         self.src_if.add_stream(self.fragments_400[0:-1])
@@ -1140,7 +1324,7 @@ class TestIPv6Reassembly(VppTestCase):
         self.verify_capture(packets)
 
     def test_reversed(self):
-        """ reverse order reassembly """
+        """reverse order reassembly"""
 
         fragments = list(self.fragments_400)
         fragments.reverse()
@@ -1163,7 +1347,7 @@ class TestIPv6Reassembly(VppTestCase):
         self.src_if.assert_nothing_captured()
 
     def test_random(self):
-        """ random order reassembly """
+        """random order reassembly"""
 
         fragments = list(self.fragments_400)
         shuffle(fragments)
@@ -1186,10 +1370,11 @@ class TestIPv6Reassembly(VppTestCase):
         self.src_if.assert_nothing_captured()
 
     def test_duplicates(self):
-        """ duplicate fragments """
+        """duplicate fragments"""
 
         fragments = [
-            x for (_, frags, _) in self.pkt_infos
+            x
+            for (_, frags, _) in self.pkt_infos
             for x in frags
             for _ in range(0, min(2, len(frags)))
         ]
@@ -1203,22 +1388,26 @@ class TestIPv6Reassembly(VppTestCase):
         self.src_if.assert_nothing_captured()
 
     def test_long_fragment_chain(self):
-        """ long fragment chain """
+        """long fragment chain"""
 
-        error_cnt_str = \
-            "/err/ip6-full-reassembly-feature/fragment chain too long (drop)"
+        error_cnt_str = "/err/ip6-full-reassembly-feature/reass_fragment_chain_too_long"
 
         error_cnt = self.statistics.get_err_counter(error_cnt_str)
 
-        self.vapi.ip_reassembly_set(timeout_ms=100, max_reassemblies=1000,
-                                    max_reassembly_length=3,
-                                    expire_walk_interval_ms=50, is_ip6=1)
+        self.vapi.ip_reassembly_set(
+            timeout_ms=100,
+            max_reassemblies=1000,
+            max_reassembly_length=3,
+            expire_walk_interval_ms=50,
+            is_ip6=1,
+        )
 
-        p = (Ether(dst=self.src_if.local_mac, src=self.src_if.remote_mac) /
-             IPv6(src=self.src_if.remote_ip6,
-                  dst=self.dst_if.remote_ip6) /
-             UDP(sport=1234, dport=5678) /
-             Raw(b"X" * 1000))
+        p = (
+            Ether(dst=self.src_if.local_mac, src=self.src_if.remote_mac)
+            / IPv6(src=self.src_if.remote_ip6, dst=self.dst_if.remote_ip6)
+            / UDP(sport=1234, dport=5678)
+            / Raw(b"X" * 1000)
+        )
         frags = fragment_rfc8200(p, 1, 300) + fragment_rfc8200(p, 2, 500)
 
         self.pg_enable_capture()
@@ -1229,7 +1418,7 @@ class TestIPv6Reassembly(VppTestCase):
         self.assert_error_counter_equal(error_cnt_str, error_cnt + 1)
 
     def test_overlap1(self):
-        """ overlapping fragments case #1 """
+        """overlapping fragments case #1"""
 
         fragments = []
         for _, frags_400, frags_300 in self.pkt_infos:
@@ -1249,12 +1438,13 @@ class TestIPv6Reassembly(VppTestCase):
         self.pg_start()
 
         packets = self.dst_if.get_capture(
-            len(self.pkt_infos) - len(dropped_packet_indexes))
+            len(self.pkt_infos) - len(dropped_packet_indexes)
+        )
         self.verify_capture(packets, dropped_packet_indexes)
         self.src_if.assert_nothing_captured()
 
     def test_overlap2(self):
-        """ overlapping fragments case #2 """
+        """overlapping fragments case #2"""
 
         fragments = []
         for _, frags_400, frags_300 in self.pkt_infos:
@@ -1280,30 +1470,35 @@ class TestIPv6Reassembly(VppTestCase):
         self.pg_start()
 
         packets = self.dst_if.get_capture(
-            len(self.pkt_infos) - len(dropped_packet_indexes))
+            len(self.pkt_infos) - len(dropped_packet_indexes)
+        )
         self.verify_capture(packets, dropped_packet_indexes)
         self.src_if.assert_nothing_captured()
 
     def test_timeout_inline(self):
-        """ timeout (inline) """
+        """timeout (inline)"""
 
         dropped_packet_indexes = set(
             index for (index, frags, _) in self.pkt_infos if len(frags) > 1
         )
 
-        self.vapi.ip_reassembly_set(timeout_ms=0, max_reassemblies=1000,
-                                    max_reassembly_length=3,
-                                    expire_walk_interval_ms=10000, is_ip6=1)
+        self.vapi.ip_reassembly_set(
+            timeout_ms=0,
+            max_reassemblies=1000,
+            max_reassembly_length=3,
+            expire_walk_interval_ms=10000,
+            is_ip6=1,
+        )
 
         self.pg_enable_capture()
         self.src_if.add_stream(self.fragments_400)
         self.pg_start()
 
         packets = self.dst_if.get_capture(
-            len(self.pkt_infos) - len(dropped_packet_indexes))
+            len(self.pkt_infos) - len(dropped_packet_indexes)
+        )
         self.verify_capture(packets, dropped_packet_indexes)
-        pkts = self.src_if.get_capture(
-            expected_count=len(dropped_packet_indexes))
+        pkts = self.src_if._get_capture(1)
         for icmp in pkts:
             self.assertIn(ICMPv6TimeExceeded, icmp)
             self.assertIn(IPv6ExtHdrFragment, icmp)
@@ -1311,45 +1506,53 @@ class TestIPv6Reassembly(VppTestCase):
             dropped_packet_indexes.remove(icmp[IPv6ExtHdrFragment].id)
 
     def test_timeout_cleanup(self):
-        """ timeout (cleanup) """
+        """timeout (cleanup)"""
 
         # whole packets + fragmented packets sans last fragment
         fragments = [
-            x for (_, frags_400, _) in self.pkt_infos
-            for x in frags_400[:-1 if len(frags_400) > 1 else None]
+            x
+            for (_, frags_400, _) in self.pkt_infos
+            for x in frags_400[: -1 if len(frags_400) > 1 else None]
         ]
 
         # last fragments for fragmented packets
-        fragments2 = [frags_400[-1]
-                      for (_, frags_400, _) in self.pkt_infos
-                      if len(frags_400) > 1]
+        fragments2 = [
+            frags_400[-1] for (_, frags_400, _) in self.pkt_infos if len(frags_400) > 1
+        ]
 
         dropped_packet_indexes = set(
-            index for (index, frags_400, _) in self.pkt_infos
-            if len(frags_400) > 1)
+            index for (index, frags_400, _) in self.pkt_infos if len(frags_400) > 1
+        )
 
-        self.vapi.ip_reassembly_set(timeout_ms=100, max_reassemblies=1000,
-                                    max_reassembly_length=1000,
-                                    expire_walk_interval_ms=50)
+        self.vapi.ip_reassembly_set(
+            timeout_ms=100,
+            max_reassemblies=1000,
+            max_reassembly_length=1000,
+            expire_walk_interval_ms=50,
+        )
 
-        self.vapi.ip_reassembly_set(timeout_ms=100, max_reassemblies=1000,
-                                    max_reassembly_length=1000,
-                                    expire_walk_interval_ms=50, is_ip6=1)
+        self.vapi.ip_reassembly_set(
+            timeout_ms=100,
+            max_reassemblies=1000,
+            max_reassembly_length=1000,
+            expire_walk_interval_ms=50,
+            is_ip6=1,
+        )
 
         self.pg_enable_capture()
         self.src_if.add_stream(fragments)
         self.pg_start()
 
-        self.sleep(.25, "wait before sending rest of fragments")
+        self.virtual_sleep(0.25, "wait before sending rest of fragments")
 
         self.src_if.add_stream(fragments2)
         self.pg_start()
 
         packets = self.dst_if.get_capture(
-            len(self.pkt_infos) - len(dropped_packet_indexes))
+            len(self.pkt_infos) - len(dropped_packet_indexes)
+        )
         self.verify_capture(packets, dropped_packet_indexes)
-        pkts = self.src_if.get_capture(
-            expected_count=len(dropped_packet_indexes))
+        pkts = self.src_if._get_capture(1)
         for icmp in pkts:
             self.assertIn(ICMPv6TimeExceeded, icmp)
             self.assertIn(IPv6ExtHdrFragment, icmp)
@@ -1357,52 +1560,68 @@ class TestIPv6Reassembly(VppTestCase):
             dropped_packet_indexes.remove(icmp[IPv6ExtHdrFragment].id)
 
     def test_disabled(self):
-        """ reassembly disabled """
+        """reassembly disabled"""
 
         dropped_packet_indexes = set(
-            index for (index, frags_400, _) in self.pkt_infos
-            if len(frags_400) > 1)
+            index for (index, frags_400, _) in self.pkt_infos if len(frags_400) > 1
+        )
 
-        self.vapi.ip_reassembly_set(timeout_ms=1000, max_reassemblies=0,
-                                    max_reassembly_length=3,
-                                    expire_walk_interval_ms=10000, is_ip6=1)
+        self.vapi.ip_reassembly_set(
+            timeout_ms=1000,
+            max_reassemblies=0,
+            max_reassembly_length=3,
+            expire_walk_interval_ms=10000,
+            is_ip6=1,
+        )
 
         self.pg_enable_capture()
         self.src_if.add_stream(self.fragments_400)
         self.pg_start()
 
         packets = self.dst_if.get_capture(
-            len(self.pkt_infos) - len(dropped_packet_indexes))
+            len(self.pkt_infos) - len(dropped_packet_indexes)
+        )
         self.verify_capture(packets, dropped_packet_indexes)
         self.src_if.assert_nothing_captured()
 
     def test_missing_upper(self):
-        """ missing upper layer """
-        p = (Ether(dst=self.src_if.local_mac, src=self.src_if.remote_mac) /
-             IPv6(src=self.src_if.remote_ip6,
-                  dst=self.src_if.local_ip6) /
-             UDP(sport=1234, dport=5678) /
-             Raw())
-        self.extend_packet(p, 1000, self.padding)
-        fragments = fragment_rfc8200(p, 1, 500)
-        bad_fragment = p.__class__(scapy.compat.raw(fragments[1]))
-        bad_fragment[IPv6ExtHdrFragment].nh = 59
-        bad_fragment[IPv6ExtHdrFragment].offset = 0
+        """missing upper layer"""
+        optdata = "\x00" * 100
+        p = (
+            Ether(dst=self.src_if.local_mac, src=self.src_if.remote_mac)
+            / IPv6(src=self.src_if.remote_ip6, dst=self.src_if.local_ip6)
+            / IPv6ExtHdrFragment(m=1)
+            / IPv6ExtHdrDestOpt(
+                nh=17, options=PadN(optdata="\101" * 255) / PadN(optdata="\102" * 255)
+            )
+        )
+
         self.pg_enable_capture()
-        self.src_if.add_stream([bad_fragment])
+        self.src_if.add_stream([p])
         self.pg_start()
         pkts = self.src_if.get_capture(expected_count=1)
         icmp = pkts[0]
         self.assertIn(ICMPv6ParamProblem, icmp)
         self.assert_equal(icmp[ICMPv6ParamProblem].code, 3, "ICMP code")
 
+    def test_truncated_fragment(self):
+        """truncated fragment"""
+        pkt = (
+            Ether(src=self.pg0.local_mac, dst=self.pg0.remote_mac)
+            / IPv6(src=self.pg0.remote_ip6, dst=self.pg0.local_ip6, nh=44, plen=2)
+            / IPv6ExtHdrFragment(nh=6)
+        )
+
+        self.send_and_assert_no_replies(self.pg0, [pkt], self.pg0)
+
     def test_invalid_frag_size(self):
-        """ fragment size not a multiple of 8 """
-        p = (Ether(dst=self.src_if.local_mac, src=self.src_if.remote_mac) /
-             IPv6(src=self.src_if.remote_ip6,
-                  dst=self.src_if.local_ip6) /
-             UDP(sport=1234, dport=5678) /
-             Raw())
+        """fragment size not a multiple of 8"""
+        p = (
+            Ether(dst=self.src_if.local_mac, src=self.src_if.remote_mac)
+            / IPv6(src=self.src_if.remote_ip6, dst=self.src_if.local_ip6)
+            / UDP(sport=1234, dport=5678)
+            / Raw()
+        )
         self.extend_packet(p, 1000, self.padding)
         fragments = fragment_rfc8200(p, 1, 500)
         bad_fragment = fragments[0]
@@ -1416,12 +1635,13 @@ class TestIPv6Reassembly(VppTestCase):
         self.assert_equal(icmp[ICMPv6ParamProblem].code, 0, "ICMP code")
 
     def test_invalid_packet_size(self):
-        """ total packet size > 65535 """
-        p = (Ether(dst=self.src_if.local_mac, src=self.src_if.remote_mac) /
-             IPv6(src=self.src_if.remote_ip6,
-                  dst=self.src_if.local_ip6) /
-             UDP(sport=1234, dport=5678) /
-             Raw())
+        """total packet size > 65535"""
+        p = (
+            Ether(dst=self.src_if.local_mac, src=self.src_if.remote_mac)
+            / IPv6(src=self.src_if.remote_ip6, dst=self.src_if.local_ip6)
+            / UDP(sport=1234, dport=5678)
+            / Raw()
+        )
         self.extend_packet(p, 1000, self.padding)
         fragments = fragment_rfc8200(p, 1, 500)
         bad_fragment = fragments[1]
@@ -1434,16 +1654,124 @@ class TestIPv6Reassembly(VppTestCase):
         self.assertIn(ICMPv6ParamProblem, icmp)
         self.assert_equal(icmp[ICMPv6ParamProblem].code, 0, "ICMP code")
 
+    def test_atomic_fragment(self):
+        """IPv6 atomic fragment"""
+        pkt = (
+            Ether(src=self.pg0.local_mac, dst=self.pg0.remote_mac)
+            / IPv6(src=self.pg0.remote_ip6, dst=self.pg0.local_ip6, nh=44, plen=65535)
+            / IPv6ExtHdrFragment(
+                offset=8191, m=1, res1=0xFF, res2=0xFF, nh=255, id=0xFFFF
+            )
+            / ("X" * 1452)
+        )
+
+        rx = self.send_and_expect(self.pg0, [pkt], self.pg0)
+        self.assertIn(ICMPv6ParamProblem, rx[0])
+
+    def test_truncated_fragment(self):
+        """IPv6 truncated fragment header"""
+        pkt = (
+            Ether(src=self.pg0.local_mac, dst=self.pg0.remote_mac)
+            / IPv6(src=self.pg0.remote_ip6, dst=self.pg0.local_ip6, nh=44, plen=2)
+            / IPv6ExtHdrFragment(nh=6)
+        )
+
+        self.send_and_assert_no_replies(self.pg0, [pkt])
+
+        pkt = (
+            Ether(src=self.pg0.local_mac, dst=self.pg0.remote_mac)
+            / IPv6(src=self.pg0.remote_ip6, dst=self.pg0.remote_ip6)
+            / ICMPv6EchoRequest()
+        )
+        rx = self.send_and_expect(self.pg0, [pkt], self.pg0)
+
+    def test_one_fragment(self):
+        """whole packet in one fragment processed independently"""
+        pkt = (
+            Ether(src=self.pg0.local_mac, dst=self.pg0.remote_mac)
+            / IPv6(src=self.pg0.remote_ip6, dst=self.pg0.local_ip6)
+            / ICMPv6EchoRequest()
+            / Raw("X" * 1600)
+        )
+        frags = fragment_rfc8200(pkt, 1, 400)
+
+        # send a fragment with known id
+        self.send_and_assert_no_replies(self.pg0, [frags[0]])
+
+        # send an atomic fragment with same id - should be reassembled
+        pkt = (
+            Ether(src=self.pg0.local_mac, dst=self.pg0.remote_mac)
+            / IPv6(src=self.pg0.remote_ip6, dst=self.pg0.local_ip6)
+            / IPv6ExtHdrFragment(id=1)
+            / ICMPv6EchoRequest()
+        )
+        rx = self.send_and_expect(self.pg0, [pkt], self.pg0)
+        self.assertNotIn(IPv6ExtHdrFragment, rx)
+
+        # now finish the original reassembly, this should still be possible
+        rx = self.send_and_expect(self.pg0, frags[1:], self.pg0, n_rx=1)
+        self.assertNotIn(IPv6ExtHdrFragment, rx)
+
+    def test_bunch_of_fragments(self):
+        """valid fragments followed by rogue fragments and atomic fragment"""
+        pkt = (
+            Ether(src=self.pg0.local_mac, dst=self.pg0.remote_mac)
+            / IPv6(src=self.pg0.remote_ip6, dst=self.pg0.local_ip6)
+            / ICMPv6EchoRequest()
+            / Raw("X" * 1600)
+        )
+        frags = fragment_rfc8200(pkt, 1, 400)
+        self.send_and_expect(self.pg0, frags, self.pg0, n_rx=1)
+
+        inc_frag = (
+            Ether(src=self.pg0.local_mac, dst=self.pg0.remote_mac)
+            / IPv6(src=self.pg0.remote_ip6, dst=self.pg0.local_ip6)
+            / IPv6ExtHdrFragment(id=1, nh=58, offset=608)
+            / Raw("X" * 308)
+        )
+
+        self.send_and_assert_no_replies(self.pg0, inc_frag * 604)
+
+        pkt = (
+            Ether(src=self.pg0.local_mac, dst=self.pg0.remote_mac)
+            / IPv6(src=self.pg0.remote_ip6, dst=self.pg0.local_ip6)
+            / IPv6ExtHdrFragment(id=1)
+            / ICMPv6EchoRequest()
+        )
+        rx = self.send_and_expect(self.pg0, [pkt], self.pg0)
+        self.assertNotIn(IPv6ExtHdrFragment, rx)
+
+    def test_local_enable_disable(self):
+        """local reassembly enabled/disable"""
+        self.vapi.ip_reassembly_enable_disable(
+            sw_if_index=self.src_if.sw_if_index, enable_ip6=False
+        )
+        self.vapi.ip_local_reass_enable_disable(enable_ip6=True)
+        pkt = (
+            Ether(src=self.src_if.local_mac, dst=self.src_if.remote_mac)
+            / IPv6(src=self.src_if.remote_ip6, dst=self.src_if.local_ip6)
+            / ICMPv6EchoRequest(id=1234)
+            / Raw("X" * 1600)
+        )
+        frags = fragment_rfc8200(pkt, 1, 400)
+        r = self.send_and_expect(self.src_if, frags, self.src_if, n_rx=1)[0]
+        self.assertEqual(1234, r[ICMPv6EchoReply].id)
+        self.vapi.ip_local_reass_enable_disable()
+
+        self.send_and_assert_no_replies(self.src_if, frags)
+        self.vapi.ip_local_reass_enable_disable(enable_ip6=True)
+
 
 class TestIPv6MWReassembly(VppTestCase):
-    """ IPv6 Reassembly (multiple workers) """
-    worker_config = "workers %d" % worker_count
+    """IPv6 Reassembly (multiple workers)"""
+
+    vpp_worker_count = 3
 
     @classmethod
     def setUpClass(cls):
-        super(TestIPv6MWReassembly, cls).setUpClass()
+        super().setUpClass()
 
-        cls.create_pg_interfaces(range(worker_count+1))
+        cls.create_pg_interfaces(range(cls.vpp_worker_count + 1))
         cls.src_if = cls.pg0
         cls.send_ifs = cls.pg_interfaces[:-1]
         cls.dst_if = cls.pg_interfaces[-1]
@@ -1457,32 +1785,49 @@ class TestIPv6MWReassembly(VppTestCase):
         # packets sizes reduced here because we are generating packets without
         # Ethernet headers, which are added later (diff fragments go via
         # different interfaces)
-        cls.packet_sizes = [64-len(Ether()), 512-len(Ether()),
-                            1518-len(Ether()), 9018-len(Ether())]
+        cls.packet_sizes = [
+            64 - len(Ether()),
+            512 - len(Ether()),
+            1518 - len(Ether()),
+            9018 - len(Ether()),
+        ]
         cls.padding = " abcdefghijklmn"
         cls.create_stream(cls.packet_sizes)
         cls.create_fragments()
 
     @classmethod
     def tearDownClass(cls):
-        super(TestIPv6MWReassembly, cls).tearDownClass()
+        super().tearDownClass()
 
     def setUp(self):
-        """ Test setup - force timeout on existing reassemblies """
-        super(TestIPv6MWReassembly, self).setUp()
+        """Test setup - force timeout on existing reassemblies"""
+        super().setUp()
         for intf in self.send_ifs:
             self.vapi.ip_reassembly_enable_disable(
-                sw_if_index=intf.sw_if_index, enable_ip6=True)
-        self.vapi.ip_reassembly_set(timeout_ms=0, max_reassemblies=1000,
-                                    max_reassembly_length=1000,
-                                    expire_walk_interval_ms=10, is_ip6=1)
-        self.sleep(.25)
-        self.vapi.ip_reassembly_set(timeout_ms=1000000, max_reassemblies=1000,
-                                    max_reassembly_length=1000,
-                                    expire_walk_interval_ms=1000, is_ip6=1)
+                sw_if_index=intf.sw_if_index, enable_ip6=True
+            )
+        self.vapi.ip_reassembly_set(
+            timeout_ms=0,
+            max_reassemblies=1000,
+            max_reassembly_length=1000,
+            expire_walk_interval_ms=10,
+            is_ip6=1,
+        )
+        self.virtual_sleep(0.25)
+        self.vapi.ip_reassembly_set(
+            timeout_ms=1000000,
+            max_reassemblies=1000,
+            max_reassembly_length=1000,
+            expire_walk_interval_ms=1000,
+            is_ip6=1,
+        )
 
     def tearDown(self):
-        super(TestIPv6MWReassembly, self).tearDown()
+        for intf in self.send_ifs:
+            self.vapi.ip_reassembly_enable_disable(
+                sw_if_index=intf.sw_if_index, enable_ip6=False
+            )
+        super().tearDown()
 
     def show_commands_at_teardown(self):
         self.logger.debug(self.vapi.ppcli("show ip6-full-reassembly details"))
@@ -1497,10 +1842,11 @@ class TestIPv6MWReassembly(VppTestCase):
         for i in range(0, packet_count):
             info = cls.create_packet_info(cls.src_if, cls.src_if)
             payload = cls.info_to_payload(info)
-            p = (IPv6(src=cls.src_if.remote_ip6,
-                      dst=cls.dst_if.remote_ip6) /
-                 UDP(sport=1234, dport=5678) /
-                 Raw(payload))
+            p = (
+                IPv6(src=cls.src_if.remote_ip6, dst=cls.dst_if.remote_ip6)
+                / UDP(sport=1234, dport=5678)
+                / Raw(payload)
+            )
             size = packet_sizes[(i // 2) % len(packet_sizes)]
             cls.extend_packet(p, size, cls.padding)
             info.data = p
@@ -1515,10 +1861,11 @@ class TestIPv6MWReassembly(VppTestCase):
             #                      p.__class__(scapy.compat.raw(p))))
             fragments_400 = fragment_rfc8200(p, index, 400)
             cls.pkt_infos.append((index, fragments_400))
-        cls.fragments_400 = [
-            x for (_, frags) in cls.pkt_infos for x in frags]
-        cls.logger.debug("Fragmented %s packets into %s 400-byte fragments, " %
-                         (len(infos), len(cls.fragments_400)))
+        cls.fragments_400 = [x for (_, frags) in cls.pkt_infos for x in frags]
+        cls.logger.debug(
+            "Fragmented %s packets into %s 400-byte fragments, "
+            % (len(infos), len(cls.fragments_400))
+        )
 
     def verify_capture(self, capture, dropped_packet_indexes=[]):
         """Verify captured packet strea .
@@ -1536,7 +1883,8 @@ class TestIPv6MWReassembly(VppTestCase):
                 packet_index = payload_info.index
                 self.assertTrue(
                     packet_index not in dropped_packet_indexes,
-                    ppp("Packet received, but should be dropped:", packet))
+                    ppp("Packet received, but should be dropped:", packet),
+                )
                 if packet_index in seen:
                     raise Exception(ppp("Duplicate packet received", packet))
                 seen.add(packet_index)
@@ -1552,39 +1900,44 @@ class TestIPv6MWReassembly(VppTestCase):
                 self.logger.error(ppp("Unexpected or invalid packet:", packet))
                 raise
         for index in self._packet_infos:
-            self.assertTrue(index in seen or index in dropped_packet_indexes,
-                            "Packet with packet_index %d not received" % index)
+            self.assertTrue(
+                index in seen or index in dropped_packet_indexes,
+                "Packet with packet_index %d not received" % index,
+            )
 
     def send_packets(self, packets):
-        for counter in range(worker_count):
+        for counter in range(self.vpp_worker_count):
             if 0 == len(packets[counter]):
                 continue
             send_if = self.send_ifs[counter]
             send_if.add_stream(
-                (Ether(dst=send_if.local_mac, src=send_if.remote_mac) / x
-                 for x in packets[counter]),
-                worker=counter)
+                (
+                    Ether(dst=send_if.local_mac, src=send_if.remote_mac) / x
+                    for x in packets[counter]
+                ),
+                worker=counter,
+            )
         self.pg_start()
 
     def test_worker_conflict(self):
-        """ 1st and FO=0 fragments on different workers """
+        """1st and FO=0 fragments on different workers"""
 
         # in first wave we send fragments which don't start at offset 0
         # then we send fragments with offset 0 on a different thread
         # then the rest of packets on a random thread
-        first_packets = [[] for n in range(worker_count)]
-        second_packets = [[] for n in range(worker_count)]
-        rest_of_packets = [[] for n in range(worker_count)]
-        for (_, p) in self.pkt_infos:
-            wi = randrange(worker_count)
+        first_packets = [[] for n in range(self.vpp_worker_count)]
+        second_packets = [[] for n in range(self.vpp_worker_count)]
+        rest_of_packets = [[] for n in range(self.vpp_worker_count)]
+        for _, p in self.pkt_infos:
+            wi = randrange(self.vpp_worker_count)
             second_packets[wi].append(p[0])
             if len(p) <= 1:
                 continue
             wi2 = wi
             while wi2 == wi:
-                wi2 = randrange(worker_count)
+                wi2 = randrange(self.vpp_worker_count)
             first_packets[wi2].append(p[1])
-            wi3 = randrange(worker_count)
+            wi3 = randrange(self.vpp_worker_count)
             rest_of_packets[wi3].extend(p[2:])
 
         self.pg_enable_capture()
@@ -1614,11 +1967,11 @@ class TestIPv6MWReassembly(VppTestCase):
 
 
 class TestIPv6SVReassembly(VppTestCase):
-    """ IPv6 Shallow Virtual Reassembly """
+    """IPv6 Shallow Virtual Reassembly"""
 
     @classmethod
     def setUpClass(cls):
-        super(TestIPv6SVReassembly, cls).setUpClass()
+        super().setUpClass()
 
         cls.create_pg_interfaces([0, 1])
         cls.src_if = cls.pg0
@@ -1631,30 +1984,38 @@ class TestIPv6SVReassembly(VppTestCase):
             i.resolve_ndp()
 
     def setUp(self):
-        """ Test setup - force timeout on existing reassemblies """
-        super(TestIPv6SVReassembly, self).setUp()
+        """Test setup - force timeout on existing reassemblies"""
+        super().setUp()
         self.vapi.ip_reassembly_enable_disable(
-            sw_if_index=self.src_if.sw_if_index, enable_ip6=True,
-            type=VppEnum.vl_api_ip_reass_type_t.IP_REASS_TYPE_SHALLOW_VIRTUAL)
+            sw_if_index=self.src_if.sw_if_index,
+            enable_ip6=True,
+            type=VppEnum.vl_api_ip_reass_type_t.IP_REASS_TYPE_SHALLOW_VIRTUAL,
+        )
         self.vapi.ip_reassembly_set(
-            timeout_ms=0, max_reassemblies=1000,
+            timeout_ms=0,
+            max_reassemblies=1000,
             max_reassembly_length=1000,
             type=VppEnum.vl_api_ip_reass_type_t.IP_REASS_TYPE_SHALLOW_VIRTUAL,
-            expire_walk_interval_ms=10, is_ip6=1)
-        self.sleep(.25)
+            expire_walk_interval_ms=10,
+            is_ip6=1,
+        )
+        self.virtual_sleep(0.25)
         self.vapi.ip_reassembly_set(
-            timeout_ms=1000000, max_reassemblies=1000,
+            timeout_ms=1000000,
+            max_reassemblies=1000,
             max_reassembly_length=1000,
             type=VppEnum.vl_api_ip_reass_type_t.IP_REASS_TYPE_SHALLOW_VIRTUAL,
-            expire_walk_interval_ms=10000, is_ip6=1)
+            expire_walk_interval_ms=10000,
+            is_ip6=1,
+        )
 
     def tearDown(self):
-        super(TestIPv6SVReassembly, self).tearDown()
+        super().tearDown()
         self.logger.debug(self.vapi.ppcli("show ip6-sv-reassembly details"))
         self.logger.debug(self.vapi.ppcli("show buffers"))
 
     def test_basic(self):
-        """ basic reassembly """
+        """basic reassembly"""
         payload_len = 1000
         payload = ""
         counter = 0
@@ -1662,11 +2023,13 @@ class TestIPv6SVReassembly(VppTestCase):
             payload += "%u " % counter
             counter += 1
 
-        p = (Ether(dst=self.src_if.local_mac, src=self.src_if.remote_mac) /
-             IPv6(src=self.src_if.remote_ip6, dst=self.dst_if.remote_ip6) /
-             UDP(sport=1234, dport=5678) /
-             Raw(payload))
-        fragments = fragment_rfc8200(p, 1, payload_len/4)
+        p = (
+            Ether(dst=self.src_if.local_mac, src=self.src_if.remote_mac)
+            / IPv6(src=self.src_if.remote_ip6, dst=self.dst_if.remote_ip6)
+            / UDP(sport=1234, dport=5678)
+            / Raw(payload)
+        )
+        fragments = fragment_rfc8200(p, 1, payload_len / 4)
 
         # send fragment #2 - should be cached inside reassembly
         self.pg_enable_capture()
@@ -1702,7 +2065,7 @@ class TestIPv6SVReassembly(VppTestCase):
             self.assertEqual(sent[Raw].payload, recvd[Raw].payload)
 
     def test_verify_clear_trace_mid_reassembly(self):
-        """ verify clear trace works mid-reassembly """
+        """verify clear trace works mid-reassembly"""
         payload_len = 1000
         payload = ""
         counter = 0
@@ -1710,11 +2073,13 @@ class TestIPv6SVReassembly(VppTestCase):
             payload += "%u " % counter
             counter += 1
 
-        p = (Ether(dst=self.src_if.local_mac, src=self.src_if.remote_mac) /
-             IPv6(src=self.src_if.remote_ip6, dst=self.dst_if.remote_ip6) /
-             UDP(sport=1234, dport=5678) /
-             Raw(payload))
-        fragments = fragment_rfc8200(p, 1, payload_len/4)
+        p = (
+            Ether(dst=self.src_if.local_mac, src=self.src_if.remote_mac)
+            / IPv6(src=self.src_if.remote_ip6, dst=self.dst_if.remote_ip6)
+            / UDP(sport=1234, dport=5678)
+            / Raw(payload)
+        )
+        fragments = fragment_rfc8200(p, 1, payload_len / 4)
 
         self.pg_enable_capture()
         self.src_if.add_stream(fragments[1])
@@ -1737,7 +2102,7 @@ class TestIPv6SVReassembly(VppTestCase):
         self.dst_if.get_capture(len(fragments[2:]))
 
     def test_timeout(self):
-        """ reassembly timeout """
+        """reassembly timeout"""
         payload_len = 1000
         payload = ""
         counter = 0
@@ -1745,18 +2110,22 @@ class TestIPv6SVReassembly(VppTestCase):
             payload += "%u " % counter
             counter += 1
 
-        p = (Ether(dst=self.src_if.local_mac, src=self.src_if.remote_mac) /
-             IPv6(src=self.src_if.remote_ip6, dst=self.dst_if.remote_ip6) /
-             UDP(sport=1234, dport=5678) /
-             Raw(payload))
-        fragments = fragment_rfc8200(p, 1, payload_len/4)
+        p = (
+            Ether(dst=self.src_if.local_mac, src=self.src_if.remote_mac)
+            / IPv6(src=self.src_if.remote_ip6, dst=self.dst_if.remote_ip6)
+            / UDP(sport=1234, dport=5678)
+            / Raw(payload)
+        )
+        fragments = fragment_rfc8200(p, 1, payload_len / 4)
 
         self.vapi.ip_reassembly_set(
-            timeout_ms=100, max_reassemblies=1000,
+            timeout_ms=100,
+            max_reassemblies=1000,
             max_reassembly_length=1000,
             expire_walk_interval_ms=50,
             is_ip6=1,
-            type=VppEnum.vl_api_ip_reass_type_t.IP_REASS_TYPE_SHALLOW_VIRTUAL)
+            type=VppEnum.vl_api_ip_reass_type_t.IP_REASS_TYPE_SHALLOW_VIRTUAL,
+        )
 
         # send fragments #2 and #1 - should be forwarded
         self.pg_enable_capture()
@@ -1772,7 +2141,7 @@ class TestIPv6SVReassembly(VppTestCase):
             self.assertEqual(sent[Raw].payload, recvd[Raw].payload)
 
         # wait for cleanup
-        self.sleep(.25, "wait before sending rest of fragments")
+        self.virtual_sleep(0.25, "wait before sending rest of fragments")
 
         # send rest of fragments - shouldn't be forwarded
         self.pg_enable_capture()
@@ -1781,13 +2150,16 @@ class TestIPv6SVReassembly(VppTestCase):
         self.dst_if.assert_nothing_captured()
 
     def test_lru(self):
-        """ reassembly reuses LRU element """
+        """reassembly reuses LRU element"""
 
         self.vapi.ip_reassembly_set(
-            timeout_ms=1000000, max_reassemblies=1,
+            timeout_ms=1000000,
+            max_reassemblies=1,
             max_reassembly_length=1000,
             type=VppEnum.vl_api_ip_reass_type_t.IP_REASS_TYPE_SHALLOW_VIRTUAL,
-            is_ip6=1, expire_walk_interval_ms=10000)
+            is_ip6=1,
+            expire_walk_interval_ms=10000,
+        )
 
         payload_len = 1000
         payload = ""
@@ -1798,15 +2170,17 @@ class TestIPv6SVReassembly(VppTestCase):
 
         packet_count = 10
 
-        fragments = [f
-                     for i in range(packet_count)
-                     for p in (Ether(dst=self.src_if.local_mac,
-                                     src=self.src_if.remote_mac) /
-                               IPv6(src=self.src_if.remote_ip6,
-                                    dst=self.dst_if.remote_ip6) /
-                               UDP(sport=1234, dport=5678) /
-                               Raw(payload))
-                     for f in fragment_rfc8200(p, i, payload_len/4)]
+        fragments = [
+            f
+            for i in range(packet_count)
+            for p in (
+                Ether(dst=self.src_if.local_mac, src=self.src_if.remote_mac)
+                / IPv6(src=self.src_if.remote_ip6, dst=self.dst_if.remote_ip6)
+                / UDP(sport=1234, dport=5678)
+                / Raw(payload)
+            )
+            for f in fragment_rfc8200(p, i, payload_len / 4)
+        ]
 
         self.pg_enable_capture()
         self.src_if.add_stream(fragments)
@@ -1817,13 +2191,76 @@ class TestIPv6SVReassembly(VppTestCase):
             self.assertEqual(sent[IPv6].dst, recvd[IPv6].dst)
             self.assertEqual(sent[Raw].payload, recvd[Raw].payload)
 
+    def test_one_fragment(self):
+        """whole packet in one fragment processed independently"""
+        pkt = (
+            Ether(src=self.src_if.local_mac, dst=self.src_if.remote_mac)
+            / IPv6(src=self.src_if.remote_ip6, dst=self.dst_if.remote_ip6)
+            / ICMPv6EchoRequest()
+            / Raw("X" * 1600)
+        )
+        frags = fragment_rfc8200(pkt, 1, 400)
+
+        # send a fragment with known id
+        self.send_and_expect(self.src_if, [frags[0]], self.dst_if)
+
+        # send an atomic fragment with same id - should be reassembled
+        pkt = (
+            Ether(src=self.src_if.local_mac, dst=self.src_if.remote_mac)
+            / IPv6(src=self.src_if.remote_ip6, dst=self.dst_if.remote_ip6)
+            / IPv6ExtHdrFragment(id=1)
+            / ICMPv6EchoRequest()
+        )
+        rx = self.send_and_expect(self.src_if, [pkt], self.dst_if)
+
+        # now forward packets matching original reassembly, should still work
+        rx = self.send_and_expect(self.src_if, frags[1:], self.dst_if)
+
+    def test_bunch_of_fragments(self):
+        """valid fragments followed by rogue fragments and atomic fragment"""
+        pkt = (
+            Ether(src=self.src_if.local_mac, dst=self.src_if.remote_mac)
+            / IPv6(src=self.src_if.remote_ip6, dst=self.dst_if.remote_ip6)
+            / ICMPv6EchoRequest()
+            / Raw("X" * 1600)
+        )
+        frags = fragment_rfc8200(pkt, 1, 400)
+        rx = self.send_and_expect(self.src_if, frags, self.dst_if)
+
+        rogue = (
+            Ether(src=self.src_if.local_mac, dst=self.src_if.remote_mac)
+            / IPv6(src=self.src_if.remote_ip6, dst=self.dst_if.remote_ip6)
+            / IPv6ExtHdrFragment(id=1, nh=58, offset=608)
+            / Raw("X" * 308)
+        )
+
+        self.send_and_expect(self.src_if, rogue * 604, self.dst_if)
+
+        pkt = (
+            Ether(src=self.src_if.local_mac, dst=self.src_if.remote_mac)
+            / IPv6(src=self.src_if.remote_ip6, dst=self.dst_if.remote_ip6)
+            / IPv6ExtHdrFragment(id=1)
+            / ICMPv6EchoRequest()
+        )
+        rx = self.send_and_expect(self.src_if, [pkt], self.dst_if)
+
+    def test_truncated_fragment(self):
+        """truncated fragment"""
+        pkt = (
+            Ether(src=self.pg0.local_mac, dst=self.pg0.remote_mac)
+            / IPv6(src=self.pg0.remote_ip6, dst=self.pg0.local_ip6, nh=44, plen=2)
+            / IPv6ExtHdrFragment(nh=6)
+        )
+
+        self.send_and_assert_no_replies(self.pg0, [pkt], self.pg0)
+
 
 class TestIPv4ReassemblyLocalNode(VppTestCase):
-    """ IPv4 Reassembly for packets coming to ip4-local node """
+    """IPv4 Reassembly for packets coming to ip4-local node"""
 
     @classmethod
     def setUpClass(cls):
-        super(TestIPv4ReassemblyLocalNode, cls).setUpClass()
+        super().setUpClass()
 
         cls.create_pg_interfaces([0])
         cls.src_dst_if = cls.pg0
@@ -1840,21 +2277,27 @@ class TestIPv4ReassemblyLocalNode(VppTestCase):
 
     @classmethod
     def tearDownClass(cls):
-        super(TestIPv4ReassemblyLocalNode, cls).tearDownClass()
+        super().tearDownClass()
 
     def setUp(self):
-        """ Test setup - force timeout on existing reassemblies """
-        super(TestIPv4ReassemblyLocalNode, self).setUp()
-        self.vapi.ip_reassembly_set(timeout_ms=0, max_reassemblies=1000,
-                                    max_reassembly_length=1000,
-                                    expire_walk_interval_ms=10)
-        self.sleep(.25)
-        self.vapi.ip_reassembly_set(timeout_ms=1000000, max_reassemblies=1000,
-                                    max_reassembly_length=1000,
-                                    expire_walk_interval_ms=10000)
+        """Test setup - force timeout on existing reassemblies"""
+        super().setUp()
+        self.vapi.ip_reassembly_set(
+            timeout_ms=0,
+            max_reassemblies=1000,
+            max_reassembly_length=1000,
+            expire_walk_interval_ms=10,
+        )
+        self.virtual_sleep(0.25)
+        self.vapi.ip_reassembly_set(
+            timeout_ms=1000000,
+            max_reassemblies=1000,
+            max_reassembly_length=1000,
+            expire_walk_interval_ms=10000,
+        )
 
     def tearDown(self):
-        super(TestIPv4ReassemblyLocalNode, self).tearDown()
+        super().tearDown()
 
     def show_commands_at_teardown(self):
         self.logger.debug(self.vapi.ppcli("show ip4-full-reassembly details"))
@@ -1869,12 +2312,16 @@ class TestIPv4ReassemblyLocalNode(VppTestCase):
         for i in range(0, packet_count):
             info = cls.create_packet_info(cls.src_dst_if, cls.src_dst_if)
             payload = cls.info_to_payload(info)
-            p = (Ether(dst=cls.src_dst_if.local_mac,
-                       src=cls.src_dst_if.remote_mac) /
-                 IP(id=info.index, src=cls.src_dst_if.remote_ip4,
-                    dst=cls.src_dst_if.local_ip4) /
-                 ICMP(type='echo-request', id=1234) /
-                 Raw(payload))
+            p = (
+                Ether(dst=cls.src_dst_if.local_mac, src=cls.src_dst_if.remote_mac)
+                / IP(
+                    id=info.index,
+                    src=cls.src_dst_if.remote_ip4,
+                    dst=cls.src_dst_if.local_ip4,
+                )
+                / ICMP(type="echo-request", id=1234)
+                / Raw(payload)
+            )
             cls.extend_packet(p, 1518, cls.padding)
             info.data = p
 
@@ -1889,8 +2336,10 @@ class TestIPv4ReassemblyLocalNode(VppTestCase):
             fragments_300 = fragment_rfc791(p, 300)
             cls.pkt_infos.append((index, fragments_300))
         cls.fragments_300 = [x for (_, frags) in cls.pkt_infos for x in frags]
-        cls.logger.debug("Fragmented %s packets into %s 300-byte fragments" %
-                         (len(infos), len(cls.fragments_300)))
+        cls.logger.debug(
+            "Fragmented %s packets into %s 300-byte fragments"
+            % (len(infos), len(cls.fragments_300))
+        )
 
     def verify_capture(self, capture):
         """Verify captured packet stream.
@@ -1923,11 +2372,12 @@ class TestIPv4ReassemblyLocalNode(VppTestCase):
                 self.logger.error(ppp("Unexpected or invalid packet:", packet))
                 raise
         for index in self._packet_infos:
-            self.assertIn(index, seen,
-                          "Packet with packet_index %d not received" % index)
+            self.assertIn(
+                index, seen, "Packet with packet_index %d not received" % index
+            )
 
     def test_reassembly(self):
-        """ basic reassembly """
+        """basic reassembly"""
 
         self.pg_enable_capture()
         self.src_dst_if.add_stream(self.fragments_300)
@@ -1946,11 +2396,11 @@ class TestIPv4ReassemblyLocalNode(VppTestCase):
 
 
 class TestFIFReassembly(VppTestCase):
-    """ Fragments in fragments reassembly """
+    """Fragments in fragments reassembly"""
 
     @classmethod
     def setUpClass(cls):
-        super(TestFIFReassembly, cls).setUpClass()
+        super().setUpClass()
 
         cls.create_pg_interfaces([0, 1])
         cls.src_if = cls.pg0
@@ -1967,33 +2417,47 @@ class TestFIFReassembly(VppTestCase):
 
     @classmethod
     def tearDownClass(cls):
-        super(TestFIFReassembly, cls).tearDownClass()
+        super().tearDownClass()
 
     def setUp(self):
-        """ Test setup - force timeout on existing reassemblies """
-        super(TestFIFReassembly, self).setUp()
+        """Test setup - force timeout on existing reassemblies"""
+        super().setUp()
         self.vapi.ip_reassembly_enable_disable(
-            sw_if_index=self.src_if.sw_if_index, enable_ip4=True,
-            enable_ip6=True)
+            sw_if_index=self.src_if.sw_if_index, enable_ip4=True, enable_ip6=True
+        )
         self.vapi.ip_reassembly_enable_disable(
-            sw_if_index=self.dst_if.sw_if_index, enable_ip4=True,
-            enable_ip6=True)
-        self.vapi.ip_reassembly_set(timeout_ms=0, max_reassemblies=1000,
-                                    max_reassembly_length=1000,
-                                    expire_walk_interval_ms=10)
-        self.vapi.ip_reassembly_set(timeout_ms=0, max_reassemblies=1000,
-                                    max_reassembly_length=1000,
-                                    expire_walk_interval_ms=10, is_ip6=1)
-        self.sleep(.25)
-        self.vapi.ip_reassembly_set(timeout_ms=1000000, max_reassemblies=1000,
-                                    max_reassembly_length=1000,
-                                    expire_walk_interval_ms=10000)
-        self.vapi.ip_reassembly_set(timeout_ms=1000000, max_reassemblies=1000,
-                                    max_reassembly_length=1000,
-                                    expire_walk_interval_ms=10000, is_ip6=1)
+            sw_if_index=self.dst_if.sw_if_index, enable_ip4=True, enable_ip6=True
+        )
+        self.vapi.ip_reassembly_set(
+            timeout_ms=0,
+            max_reassemblies=1000,
+            max_reassembly_length=1000,
+            expire_walk_interval_ms=10,
+        )
+        self.vapi.ip_reassembly_set(
+            timeout_ms=0,
+            max_reassemblies=1000,
+            max_reassembly_length=1000,
+            expire_walk_interval_ms=10,
+            is_ip6=1,
+        )
+        self.virtual_sleep(0.25)
+        self.vapi.ip_reassembly_set(
+            timeout_ms=1000000,
+            max_reassemblies=1000,
+            max_reassembly_length=1000,
+            expire_walk_interval_ms=10000,
+        )
+        self.vapi.ip_reassembly_set(
+            timeout_ms=1000000,
+            max_reassemblies=1000,
+            max_reassembly_length=1000,
+            expire_walk_interval_ms=10000,
+            is_ip6=1,
+        )
 
     def tearDown(self):
-        super(TestFIFReassembly, self).tearDown()
+        super().tearDown()
 
     def show_commands_at_teardown(self):
         self.logger.debug(self.vapi.ppcli("show ip4-full-reassembly details"))
@@ -2016,7 +2480,8 @@ class TestFIFReassembly(VppTestCase):
                 packet_index = payload_info.index
                 self.assertTrue(
                     packet_index not in dropped_packet_indexes,
-                    ppp("Packet received, but should be dropped:", packet))
+                    ppp("Packet received, but should be dropped:", packet),
+                )
                 if packet_index in seen:
                     raise Exception(ppp("Duplicate packet received", packet))
                 seen.add(packet_index)
@@ -2032,11 +2497,13 @@ class TestFIFReassembly(VppTestCase):
                 self.logger.error(ppp("Unexpected or invalid packet:", packet))
                 raise
         for index in self._packet_infos:
-            self.assertTrue(index in seen or index in dropped_packet_indexes,
-                            "Packet with packet_index %d not received" % index)
+            self.assertTrue(
+                index in seen or index in dropped_packet_indexes,
+                "Packet with packet_index %d not received" % index,
+            )
 
     def test_fif4(self):
-        """ Fragments in fragments (4o4) """
+        """Fragments in fragments (4o4)"""
 
         # TODO this should be ideally in setUpClass, but then we hit a bug
         # with VppIpRoute incorrectly reporting it's present when it's not
@@ -2050,11 +2517,15 @@ class TestFIFReassembly(VppTestCase):
         self.gre4.config_ip4()
 
         self.vapi.ip_reassembly_enable_disable(
-            sw_if_index=self.gre4.sw_if_index, enable_ip4=True)
+            sw_if_index=self.gre4.sw_if_index, enable_ip4=True
+        )
 
-        self.route4 = VppIpRoute(self, self.tun_ip4, 32,
-                                 [VppRoutePath(self.src_if.remote_ip4,
-                                               self.src_if.sw_if_index)])
+        self.route4 = VppIpRoute(
+            self,
+            self.tun_ip4,
+            32,
+            [VppRoutePath(self.src_if.remote_ip4, self.src_if.sw_if_index)],
+        )
         self.route4.add_vpp_config()
 
         self.reset_packet_infos()
@@ -2064,28 +2535,33 @@ class TestFIFReassembly(VppTestCase):
             # Ethernet header here is only for size calculation, thus it
             # doesn't matter how it's initialized. This is to ensure that
             # reassembled packet is not > 9000 bytes, so that it's not dropped
-            p = (Ether() /
-                 IP(id=i, src=self.src_if.remote_ip4,
-                    dst=self.dst_if.remote_ip4) /
-                 UDP(sport=1234, dport=5678) /
-                 Raw(payload))
+            p = (
+                Ether()
+                / IP(id=i, src=self.src_if.remote_ip4, dst=self.dst_if.remote_ip4)
+                / UDP(sport=1234, dport=5678)
+                / Raw(payload)
+            )
             size = self.packet_sizes[(i // 2) % len(self.packet_sizes)]
             self.extend_packet(p, size, self.padding)
             info.data = p[IP]  # use only IP part, without ethernet header
 
-        fragments = [x for _, p in self._packet_infos.items()
-                     for x in fragment_rfc791(p.data, 400)]
+        fragments = [
+            x
+            for _, p in self._packet_infos.items()
+            for x in fragment_rfc791(p.data, 400)
+        ]
 
-        encapped_fragments = \
-            [Ether(dst=self.src_if.local_mac, src=self.src_if.remote_mac) /
-             IP(src=self.tun_ip4, dst=self.src_if.local_ip4) /
-                GRE() /
-                p
-                for p in fragments]
+        encapped_fragments = [
+            Ether(dst=self.src_if.local_mac, src=self.src_if.remote_mac)
+            / IP(src=self.tun_ip4, dst=self.src_if.local_ip4)
+            / GRE()
+            / p
+            for p in fragments
+        ]
 
-        fragmented_encapped_fragments = \
-            [x for p in encapped_fragments
-             for x in fragment_rfc791(p, 200)]
+        fragmented_encapped_fragments = [
+            x for p in encapped_fragments for x in fragment_rfc791(p, 200)
+        ]
 
         self.src_if.add_stream(fragmented_encapped_fragments)
 
@@ -2102,7 +2578,7 @@ class TestFIFReassembly(VppTestCase):
         self.logger.debug(self.vapi.ppcli("show interface"))
 
     def test_fif6(self):
-        """ Fragments in fragments (6o6) """
+        """Fragments in fragments (6o6)"""
         # TODO this should be ideally in setUpClass, but then we hit a bug
         # with VppIpRoute incorrectly reporting it's present when it's not
         # so we need to manually remove the vpp config, thus we cannot have
@@ -2115,12 +2591,15 @@ class TestFIFReassembly(VppTestCase):
         self.gre6.config_ip6()
 
         self.vapi.ip_reassembly_enable_disable(
-            sw_if_index=self.gre6.sw_if_index, enable_ip6=True)
+            sw_if_index=self.gre6.sw_if_index, enable_ip6=True
+        )
 
-        self.route6 = VppIpRoute(self, self.tun_ip6, 128,
-                                 [VppRoutePath(
-                                     self.src_if.remote_ip6,
-                                     self.src_if.sw_if_index)])
+        self.route6 = VppIpRoute(
+            self,
+            self.tun_ip6,
+            128,
+            [VppRoutePath(self.src_if.remote_ip6, self.src_if.sw_if_index)],
+        )
         self.route6.add_vpp_config()
 
         self.reset_packet_infos()
@@ -2130,34 +2609,41 @@ class TestFIFReassembly(VppTestCase):
             # Ethernet header here is only for size calculation, thus it
             # doesn't matter how it's initialized. This is to ensure that
             # reassembled packet is not > 9000 bytes, so that it's not dropped
-            p = (Ether() /
-                 IPv6(src=self.src_if.remote_ip6, dst=self.dst_if.remote_ip6) /
-                 UDP(sport=1234, dport=5678) /
-                 Raw(payload))
+            p = (
+                Ether()
+                / IPv6(src=self.src_if.remote_ip6, dst=self.dst_if.remote_ip6)
+                / UDP(sport=1234, dport=5678)
+                / Raw(payload)
+            )
             size = self.packet_sizes[(i // 2) % len(self.packet_sizes)]
             self.extend_packet(p, size, self.padding)
             info.data = p[IPv6]  # use only IPv6 part, without ethernet header
 
-        fragments = [x for _, i in self._packet_infos.items()
-                     for x in fragment_rfc8200(
-                         i.data, i.index, 400)]
+        fragments = [
+            x
+            for _, i in self._packet_infos.items()
+            for x in fragment_rfc8200(i.data, i.index, 400)
+        ]
 
-        encapped_fragments = \
-            [Ether(dst=self.src_if.local_mac, src=self.src_if.remote_mac) /
-             IPv6(src=self.tun_ip6, dst=self.src_if.local_ip6) /
-                GRE() /
-                p
-                for p in fragments]
+        encapped_fragments = [
+            Ether(dst=self.src_if.local_mac, src=self.src_if.remote_mac)
+            / IPv6(src=self.tun_ip6, dst=self.src_if.local_ip6)
+            / GRE()
+            / p
+            for p in fragments
+        ]
 
-        fragmented_encapped_fragments = \
-            [x for p in encapped_fragments for x in (
+        fragmented_encapped_fragments = [
+            x
+            for p in encapped_fragments
+            for x in (
                 fragment_rfc8200(
-                    p,
-                    2 * len(self._packet_infos) + p[IPv6ExtHdrFragment].id,
-                    200)
-                if IPv6ExtHdrFragment in p else [p]
+                    p, 2 * len(self._packet_infos) + p[IPv6ExtHdrFragment].id, 200
+                )
+                if IPv6ExtHdrFragment in p
+                else [p]
             )
-            ]
+        ]
 
         self.src_if.add_stream(fragmented_encapped_fragments)
 
@@ -2173,5 +2659,5 @@ class TestFIFReassembly(VppTestCase):
         self.gre6.remove_vpp_config()
 
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     unittest.main(testRunner=VppTestRunner)