tests: replace pycodestyle with black
[vpp.git] / test / test_nat44_ed.py
index 21eebb2..7745987 100644 (file)
@@ -21,9 +21,9 @@ from util import StatsDiff
 
 
 class TestNAT44ED(VppTestCase):
-    """ NAT44ED Test Case """
+    """NAT44ED Test Case"""
 
-    nat_addr = '10.0.10.3'
+    nat_addr = "10.0.10.3"
 
     tcp_port_in = 6303
     tcp_port_out = 6303
@@ -48,8 +48,7 @@ class TestNAT44ED(VppTestCase):
             self.plugin_disable()
 
     def plugin_enable(self):
-        self.vapi.nat44_ed_plugin_enable_disable(
-            sessions=self.max_sessions, enable=1)
+        self.vapi.nat44_ed_plugin_enable_disable(sessions=self.max_sessions, enable=1)
 
     def plugin_disable(self):
         self.vapi.nat44_ed_plugin_enable_disable(enable=0)
@@ -87,7 +86,7 @@ class TestNAT44ED(VppTestCase):
 
     @classmethod
     def create_and_add_ip4_table(cls, i, table_id=0):
-        cls.vapi.ip_table_add_del(is_add=1, table={'table_id': table_id})
+        cls.vapi.ip_table_add_del(is_add=1, table={"table_id": table_id})
         i.set_table_ip4(table_id)
 
     @classmethod
@@ -105,32 +104,41 @@ class TestNAT44ED(VppTestCase):
 
     @classmethod
     def nat_add_interface_address(cls, i):
-        cls.vapi.nat44_add_del_interface_addr(
-            sw_if_index=i.sw_if_index, is_add=1)
+        cls.vapi.nat44_add_del_interface_addr(sw_if_index=i.sw_if_index, is_add=1)
 
     def nat_add_inside_interface(self, i):
         self.vapi.nat44_interface_add_del_feature(
-            flags=self.config_flags.NAT_IS_INSIDE,
-            sw_if_index=i.sw_if_index, is_add=1)
+            flags=self.config_flags.NAT_IS_INSIDE, sw_if_index=i.sw_if_index, is_add=1
+        )
 
     def nat_add_outside_interface(self, i):
         self.vapi.nat44_interface_add_del_feature(
-            flags=self.config_flags.NAT_IS_OUTSIDE,
-            sw_if_index=i.sw_if_index, is_add=1)
+            flags=self.config_flags.NAT_IS_OUTSIDE, sw_if_index=i.sw_if_index, is_add=1
+        )
 
-    def nat_add_address(self, address, twice_nat=0,
-                        vrf_id=0xFFFFFFFF, is_add=1):
+    def nat_add_address(self, address, twice_nat=0, vrf_id=0xFFFFFFFF, is_add=1):
         flags = self.config_flags.NAT_IS_TWICE_NAT if twice_nat else 0
-        self.vapi.nat44_add_del_address_range(first_ip_address=address,
-                                              last_ip_address=address,
-                                              vrf_id=vrf_id,
-                                              is_add=is_add,
-                                              flags=flags)
+        self.vapi.nat44_add_del_address_range(
+            first_ip_address=address,
+            last_ip_address=address,
+            vrf_id=vrf_id,
+            is_add=is_add,
+            flags=flags,
+        )
 
-    def nat_add_static_mapping(self, local_ip, external_ip='0.0.0.0',
-                               local_port=0, external_port=0, vrf_id=0,
-                               is_add=1, external_sw_if_index=0xFFFFFFFF,
-                               proto=0, tag="", flags=0):
+    def nat_add_static_mapping(
+        self,
+        local_ip,
+        external_ip="0.0.0.0",
+        local_port=0,
+        external_port=0,
+        vrf_id=0,
+        is_add=1,
+        external_sw_if_index=0xFFFFFFFF,
+        proto=0,
+        tag="",
+        flags=0,
+    ):
 
         if not (local_port and external_port):
             flags |= self.config_flags.NAT_IS_ADDR_ONLY
@@ -142,9 +150,11 @@ class TestNAT44ED(VppTestCase):
             external_sw_if_index=external_sw_if_index,
             local_port=local_port,
             external_port=external_port,
-            vrf_id=vrf_id, protocol=proto,
+            vrf_id=vrf_id,
+            protocol=proto,
             flags=flags,
-            tag=tag)
+            tag=tag,
+        )
 
     @classmethod
     def setUpClass(cls):
@@ -159,14 +169,14 @@ class TestNAT44ED(VppTestCase):
             cls.configure_ip4_interface(i, hosts=3)
 
         # test specific (test-multiple-vrf)
-        cls.vapi.ip_table_add_del(is_add=1, table={'table_id': 1})
+        cls.vapi.ip_table_add_del(is_add=1, table={"table_id": 1})
 
         # test specific (test-one-armed-nat44-static)
         cls.pg4.generate_remote_hosts(2)
         cls.pg4.config_ip4()
         cls.vapi.sw_interface_add_del_address(
-            sw_if_index=cls.pg4.sw_if_index,
-            prefix="10.0.0.1/24")
+            sw_if_index=cls.pg4.sw_if_index, prefix="10.0.0.1/24"
+        )
         cls.pg4.admin_up()
         cls.pg4.resolve_arp()
         cls.pg4._remote_hosts[1]._ip4 = cls.pg4._remote_hosts[0]._ip4
@@ -190,58 +200,95 @@ class TestNAT44ED(VppTestCase):
 
         rl = list()
 
-        rl.append(VppIpRoute(cls, "0.0.0.0", 0,
-                             [VppRoutePath("0.0.0.0", 0xffffffff,
-                                           nh_table_id=0)],
-                             register=False, table_id=1))
-        rl.append(VppIpRoute(cls, "0.0.0.0", 0,
-                             [VppRoutePath(cls.pg1.local_ip4,
-                                           cls.pg1.sw_if_index)],
-                             register=False))
-        rl.append(VppIpRoute(cls, cls.pg5.remote_ip4, 32,
-                             [VppRoutePath("0.0.0.0",
-                                           cls.pg5.sw_if_index)],
-                             register=False, table_id=1))
-        rl.append(VppIpRoute(cls, cls.pg6.remote_ip4, 32,
-                             [VppRoutePath("0.0.0.0",
-                                           cls.pg6.sw_if_index)],
-                             register=False, table_id=1))
-        rl.append(VppIpRoute(cls, cls.pg6.remote_ip4, 16,
-                             [VppRoutePath("0.0.0.0", 0xffffffff,
-                                           nh_table_id=1)],
-                             register=False, table_id=0))
+        rl.append(
+            VppIpRoute(
+                cls,
+                "0.0.0.0",
+                0,
+                [VppRoutePath("0.0.0.0", 0xFFFFFFFF, nh_table_id=0)],
+                register=False,
+                table_id=1,
+            )
+        )
+        rl.append(
+            VppIpRoute(
+                cls,
+                "0.0.0.0",
+                0,
+                [VppRoutePath(cls.pg1.local_ip4, cls.pg1.sw_if_index)],
+                register=False,
+            )
+        )
+        rl.append(
+            VppIpRoute(
+                cls,
+                cls.pg5.remote_ip4,
+                32,
+                [VppRoutePath("0.0.0.0", cls.pg5.sw_if_index)],
+                register=False,
+                table_id=1,
+            )
+        )
+        rl.append(
+            VppIpRoute(
+                cls,
+                cls.pg6.remote_ip4,
+                32,
+                [VppRoutePath("0.0.0.0", cls.pg6.sw_if_index)],
+                register=False,
+                table_id=1,
+            )
+        )
+        rl.append(
+            VppIpRoute(
+                cls,
+                cls.pg6.remote_ip4,
+                16,
+                [VppRoutePath("0.0.0.0", 0xFFFFFFFF, nh_table_id=1)],
+                register=False,
+                table_id=0,
+            )
+        )
 
         for r in rl:
             r.add_vpp_config()
 
-        cls.no_diff = StatsDiff({
-            pg.sw_if_index: {
-                '/nat44-ed/in2out/fastpath/tcp': 0,
-                '/nat44-ed/in2out/fastpath/udp': 0,
-                '/nat44-ed/in2out/fastpath/icmp': 0,
-                '/nat44-ed/in2out/fastpath/drops': 0,
-                '/nat44-ed/in2out/slowpath/tcp': 0,
-                '/nat44-ed/in2out/slowpath/udp': 0,
-                '/nat44-ed/in2out/slowpath/icmp': 0,
-                '/nat44-ed/in2out/slowpath/drops': 0,
-                '/nat44-ed/in2out/fastpath/tcp': 0,
-                '/nat44-ed/in2out/fastpath/udp': 0,
-                '/nat44-ed/in2out/fastpath/icmp': 0,
-                '/nat44-ed/in2out/fastpath/drops': 0,
-                '/nat44-ed/in2out/slowpath/tcp': 0,
-                '/nat44-ed/in2out/slowpath/udp': 0,
-                '/nat44-ed/in2out/slowpath/icmp': 0,
-                '/nat44-ed/in2out/slowpath/drops': 0,
+        cls.no_diff = StatsDiff(
+            {
+                pg.sw_if_index: {
+                    "/nat44-ed/in2out/fastpath/tcp": 0,
+                    "/nat44-ed/in2out/fastpath/udp": 0,
+                    "/nat44-ed/in2out/fastpath/icmp": 0,
+                    "/nat44-ed/in2out/fastpath/drops": 0,
+                    "/nat44-ed/in2out/slowpath/tcp": 0,
+                    "/nat44-ed/in2out/slowpath/udp": 0,
+                    "/nat44-ed/in2out/slowpath/icmp": 0,
+                    "/nat44-ed/in2out/slowpath/drops": 0,
+                    "/nat44-ed/in2out/fastpath/tcp": 0,
+                    "/nat44-ed/in2out/fastpath/udp": 0,
+                    "/nat44-ed/in2out/fastpath/icmp": 0,
+                    "/nat44-ed/in2out/fastpath/drops": 0,
+                    "/nat44-ed/in2out/slowpath/tcp": 0,
+                    "/nat44-ed/in2out/slowpath/udp": 0,
+                    "/nat44-ed/in2out/slowpath/icmp": 0,
+                    "/nat44-ed/in2out/slowpath/drops": 0,
+                }
+                for pg in cls.pg_interfaces
             }
-            for pg in cls.pg_interfaces
-        })
+        )
 
     def get_err_counter(self, path):
         return self.statistics.get_err_counter(path)
 
-    def reass_hairpinning(self, server_addr, server_in_port, server_out_port,
-                          host_in_port, proto=IP_PROTOS.tcp,
-                          ignore_port=False):
+    def reass_hairpinning(
+        self,
+        server_addr,
+        server_in_port,
+        server_out_port,
+        host_in_port,
+        proto=IP_PROTOS.tcp,
+        ignore_port=False,
+    ):
         layer = self.proto2layer(proto)
 
         if proto == IP_PROTOS.tcp:
@@ -250,19 +297,14 @@ class TestNAT44ED(VppTestCase):
             data = b"A" * 16 + b"B" * 16 + b"C" * 3
 
         # send packet from host to server
-        pkts = self.create_stream_frag(self.pg0,
-                                       self.nat_addr,
-                                       host_in_port,
-                                       server_out_port,
-                                       data,
-                                       proto)
+        pkts = self.create_stream_frag(
+            self.pg0, self.nat_addr, host_in_port, server_out_port, data, proto
+        )
         self.pg0.add_stream(pkts)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
         frags = self.pg0.get_capture(len(pkts))
-        p = self.reass_frags_and_verify(frags,
-                                        self.nat_addr,
-                                        server_addr)
+        p = self.reass_frags_and_verify(frags, self.nat_addr, server_addr)
         if proto != IP_PROTOS.icmp:
             if not ignore_port:
                 self.assertNotEqual(p[layer].sport, host_in_port)
@@ -272,8 +314,9 @@ class TestNAT44ED(VppTestCase):
                 self.assertNotEqual(p[layer].id, host_in_port)
         self.assertEqual(data, p[Raw].load)
 
-    def frag_out_of_order(self, proto=IP_PROTOS.tcp, dont_translate=False,
-                          ignore_port=False):
+    def frag_out_of_order(
+        self, proto=IP_PROTOS.tcp, dont_translate=False, ignore_port=False
+    ):
         layer = self.proto2layer(proto)
 
         if proto == IP_PROTOS.tcp:
@@ -284,21 +327,22 @@ class TestNAT44ED(VppTestCase):
 
         for i in range(2):
             # in2out
-            pkts = self.create_stream_frag(self.pg0, self.pg1.remote_ip4,
-                                           self.port_in, 20, data, proto)
+            pkts = self.create_stream_frag(
+                self.pg0, self.pg1.remote_ip4, self.port_in, 20, data, proto
+            )
             pkts.reverse()
             self.pg0.add_stream(pkts)
             self.pg_enable_capture(self.pg_interfaces)
             self.pg_start()
             frags = self.pg1.get_capture(len(pkts))
             if not dont_translate:
-                p = self.reass_frags_and_verify(frags,
-                                                self.nat_addr,
-                                                self.pg1.remote_ip4)
+                p = self.reass_frags_and_verify(
+                    frags, self.nat_addr, self.pg1.remote_ip4
+                )
             else:
-                p = self.reass_frags_and_verify(frags,
-                                                self.pg0.remote_ip4,
-                                                self.pg1.remote_ip4)
+                p = self.reass_frags_and_verify(
+                    frags, self.pg0.remote_ip4, self.pg1.remote_ip4
+                )
             if proto != IP_PROTOS.icmp:
                 if not dont_translate:
                     self.assertEqual(p[layer].dport, 20)
@@ -325,17 +369,18 @@ class TestNAT44ED(VppTestCase):
             else:
                 sport = p[layer].id
                 dport = 0
-            pkts = self.create_stream_frag(self.pg1, dst_addr, sport, dport,
-                                           data, proto, echo_reply=True)
+            pkts = self.create_stream_frag(
+                self.pg1, dst_addr, sport, dport, data, proto, echo_reply=True
+            )
             pkts.reverse()
             self.pg1.add_stream(pkts)
             self.pg_enable_capture(self.pg_interfaces)
             self.logger.info(self.vapi.cli("show trace"))
             self.pg_start()
             frags = self.pg0.get_capture(len(pkts))
-            p = self.reass_frags_and_verify(frags,
-                                            self.pg1.remote_ip4,
-                                            self.pg0.remote_ip4)
+            p = self.reass_frags_and_verify(
+                frags, self.pg1.remote_ip4, self.pg0.remote_ip4
+            )
             if proto != IP_PROTOS.icmp:
                 self.assertEqual(p[layer].sport, 20)
                 self.assertEqual(p[layer].dport, self.port_in)
@@ -351,21 +396,20 @@ class TestNAT44ED(VppTestCase):
             self.assert_ip_checksum_valid(p)
             buffer.seek(p[IP].frag * 8)
             buffer.write(bytes(p[IP].payload))
-        ip = IP(src=frags[0][IP].src, dst=frags[0][IP].dst,
-                proto=frags[0][IP].proto)
+        ip = IP(src=frags[0][IP].src, dst=frags[0][IP].dst, proto=frags[0][IP].proto)
         if ip.proto == IP_PROTOS.tcp:
-            p = (ip / TCP(buffer.getvalue()))
+            p = ip / TCP(buffer.getvalue())
             self.logger.debug(ppp("Reassembled:", p))
             self.assert_tcp_checksum_valid(p)
         elif ip.proto == IP_PROTOS.udp:
-            p = (ip / UDP(buffer.getvalue()[:8]) /
-                 Raw(buffer.getvalue()[8:]))
+            p = ip / UDP(buffer.getvalue()[:8]) / Raw(buffer.getvalue()[8:])
         elif ip.proto == IP_PROTOS.icmp:
-            p = (ip / ICMP(buffer.getvalue()))
+            p = ip / ICMP(buffer.getvalue())
         return p
 
-    def frag_in_order(self, proto=IP_PROTOS.tcp, dont_translate=False,
-                      ignore_port=False):
+    def frag_in_order(
+        self, proto=IP_PROTOS.tcp, dont_translate=False, ignore_port=False
+    ):
         layer = self.proto2layer(proto)
 
         if proto == IP_PROTOS.tcp:
@@ -375,20 +419,19 @@ class TestNAT44ED(VppTestCase):
         self.port_in = self.random_port()
 
         # in2out
-        pkts = self.create_stream_frag(self.pg0, self.pg1.remote_ip4,
-                                       self.port_in, 20, data, proto)
+        pkts = self.create_stream_frag(
+            self.pg0, self.pg1.remote_ip4, self.port_in, 20, data, proto
+        )
         self.pg0.add_stream(pkts)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
         frags = self.pg1.get_capture(len(pkts))
         if not dont_translate:
-            p = self.reass_frags_and_verify(frags,
-                                            self.nat_addr,
-                                            self.pg1.remote_ip4)
+            p = self.reass_frags_and_verify(frags, self.nat_addr, self.pg1.remote_ip4)
         else:
-            p = self.reass_frags_and_verify(frags,
-                                            self.pg0.remote_ip4,
-                                            self.pg1.remote_ip4)
+            p = self.reass_frags_and_verify(
+                frags, self.pg0.remote_ip4, self.pg1.remote_ip4
+            )
         if proto != IP_PROTOS.icmp:
             if not dont_translate:
                 self.assertEqual(p[layer].dport, 20)
@@ -415,15 +458,14 @@ class TestNAT44ED(VppTestCase):
         else:
             sport = p[layer].id
             dport = 0
-        pkts = self.create_stream_frag(self.pg1, dst_addr, sport, dport, data,
-                                       proto, echo_reply=True)
+        pkts = self.create_stream_frag(
+            self.pg1, dst_addr, sport, dport, data, proto, echo_reply=True
+        )
         self.pg1.add_stream(pkts)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
         frags = self.pg0.get_capture(len(pkts))
-        p = self.reass_frags_and_verify(frags,
-                                        self.pg1.remote_ip4,
-                                        self.pg0.remote_ip4)
+        p = self.reass_frags_and_verify(frags, self.pg1.remote_ip4, self.pg0.remote_ip4)
         if proto != IP_PROTOS.icmp:
             self.assertEqual(p[layer].sport, 20)
             self.assertEqual(p[layer].dport, self.port_in)
@@ -431,8 +473,9 @@ class TestNAT44ED(VppTestCase):
             self.assertEqual(p[layer].id, self.port_in)
         self.assertEqual(data, p[Raw].load)
 
-    def verify_capture_out(self, capture, nat_ip=None, same_port=False,
-                           dst_ip=None, ignore_port=False):
+    def verify_capture_out(
+        self, capture, nat_ip=None, same_port=False, dst_ip=None, ignore_port=False
+    ):
         if nat_ip is None:
             nat_ip = self.nat_addr
         for packet in capture:
@@ -444,35 +487,30 @@ class TestNAT44ED(VppTestCase):
                 if packet.haslayer(TCP):
                     if not ignore_port:
                         if same_port:
-                            self.assertEqual(
-                                packet[TCP].sport, self.tcp_port_in)
+                            self.assertEqual(packet[TCP].sport, self.tcp_port_in)
                         else:
-                            self.assertNotEqual(
-                                packet[TCP].sport, self.tcp_port_in)
+                            self.assertNotEqual(packet[TCP].sport, self.tcp_port_in)
                     self.tcp_port_out = packet[TCP].sport
                     self.assert_packet_checksums_valid(packet)
                 elif packet.haslayer(UDP):
                     if not ignore_port:
                         if same_port:
-                            self.assertEqual(
-                                packet[UDP].sport, self.udp_port_in)
+                            self.assertEqual(packet[UDP].sport, self.udp_port_in)
                         else:
-                            self.assertNotEqual(
-                                packet[UDP].sport, self.udp_port_in)
+                            self.assertNotEqual(packet[UDP].sport, self.udp_port_in)
                     self.udp_port_out = packet[UDP].sport
                 else:
                     if not ignore_port:
                         if same_port:
-                            self.assertEqual(
-                                packet[ICMP].id, self.icmp_id_in)
+                            self.assertEqual(packet[ICMP].id, self.icmp_id_in)
                         else:
-                            self.assertNotEqual(
-                                packet[ICMP].id, self.icmp_id_in)
+                            self.assertNotEqual(packet[ICMP].id, self.icmp_id_in)
                     self.icmp_id_out = packet[ICMP].id
                     self.assert_packet_checksums_valid(packet)
             except:
-                self.logger.error(ppp("Unexpected or invalid packet "
-                                      "(outside network):", packet))
+                self.logger.error(
+                    ppp("Unexpected or invalid packet (outside network):", packet)
+                )
                 raise
 
     def verify_capture_in(self, capture, in_if):
@@ -487,8 +525,9 @@ class TestNAT44ED(VppTestCase):
                 else:
                     self.assertEqual(packet[ICMP].id, self.icmp_id_in)
             except:
-                self.logger.error(ppp("Unexpected or invalid packet "
-                                      "(inside network):", packet))
+                self.logger.error(
+                    ppp("Unexpected or invalid packet (inside network):", packet)
+                )
                 raise
 
     def create_stream_in(self, in_if, out_if, dst_ip=None, ttl=64):
@@ -497,27 +536,32 @@ class TestNAT44ED(VppTestCase):
 
         pkts = []
         # TCP
-        p = (Ether(dst=in_if.local_mac, src=in_if.remote_mac) /
-             IP(src=in_if.remote_ip4, dst=dst_ip, ttl=ttl) /
-             TCP(sport=self.tcp_port_in, dport=20))
+        p = (
+            Ether(dst=in_if.local_mac, src=in_if.remote_mac)
+            / IP(src=in_if.remote_ip4, dst=dst_ip, ttl=ttl)
+            / TCP(sport=self.tcp_port_in, dport=20)
+        )
         pkts.extend([p, p])
 
         # UDP
-        p = (Ether(dst=in_if.local_mac, src=in_if.remote_mac) /
-             IP(src=in_if.remote_ip4, dst=dst_ip, ttl=ttl) /
-             UDP(sport=self.udp_port_in, dport=20))
+        p = (
+            Ether(dst=in_if.local_mac, src=in_if.remote_mac)
+            / IP(src=in_if.remote_ip4, dst=dst_ip, ttl=ttl)
+            / UDP(sport=self.udp_port_in, dport=20)
+        )
         pkts.append(p)
 
         # ICMP
-        p = (Ether(dst=in_if.local_mac, src=in_if.remote_mac) /
-             IP(src=in_if.remote_ip4, dst=dst_ip, ttl=ttl) /
-             ICMP(id=self.icmp_id_in, type='echo-request'))
+        p = (
+            Ether(dst=in_if.local_mac, src=in_if.remote_mac)
+            / IP(src=in_if.remote_ip4, dst=dst_ip, ttl=ttl)
+            / ICMP(id=self.icmp_id_in, type="echo-request")
+        )
         pkts.append(p)
 
         return pkts
 
-    def create_stream_out(self, out_if, dst_ip=None, ttl=64,
-                          use_inside_ports=False):
+    def create_stream_out(self, out_if, dst_ip=None, ttl=64, use_inside_ports=False):
         if dst_ip is None:
             dst_ip = self.nat_addr
         if not use_inside_ports:
@@ -530,21 +574,27 @@ class TestNAT44ED(VppTestCase):
             icmp_id = self.icmp_id_in
         pkts = []
         # TCP
-        p = (Ether(dst=out_if.local_mac, src=out_if.remote_mac) /
-             IP(src=out_if.remote_ip4, dst=dst_ip, ttl=ttl) /
-             TCP(dport=tcp_port, sport=20))
+        p = (
+            Ether(dst=out_if.local_mac, src=out_if.remote_mac)
+            / IP(src=out_if.remote_ip4, dst=dst_ip, ttl=ttl)
+            / TCP(dport=tcp_port, sport=20)
+        )
         pkts.extend([p, p])
 
         # UDP
-        p = (Ether(dst=out_if.local_mac, src=out_if.remote_mac) /
-             IP(src=out_if.remote_ip4, dst=dst_ip, ttl=ttl) /
-             UDP(dport=udp_port, sport=20))
+        p = (
+            Ether(dst=out_if.local_mac, src=out_if.remote_mac)
+            / IP(src=out_if.remote_ip4, dst=dst_ip, ttl=ttl)
+            / UDP(dport=udp_port, sport=20)
+        )
         pkts.append(p)
 
         # ICMP
-        p = (Ether(dst=out_if.local_mac, src=out_if.remote_mac) /
-             IP(src=out_if.remote_ip4, dst=dst_ip, ttl=ttl) /
-             ICMP(id=icmp_id, type='echo-reply'))
+        p = (
+            Ether(dst=out_if.local_mac, src=out_if.remote_mac)
+            / IP(src=out_if.remote_ip4, dst=dst_ip, ttl=ttl)
+            / ICMP(id=icmp_id, type="echo-reply")
+        )
         pkts.append(p)
 
         return pkts
@@ -554,19 +604,24 @@ class TestNAT44ED(VppTestCase):
         port = 6303
 
         for i in range(count):
-            p = (Ether(dst=in_if.local_mac, src=in_if.remote_mac) /
-                 IP(src=in_if.remote_ip4, dst=out_if.remote_ip4, ttl=64) /
-                 TCP(sport=port + i, dport=20))
+            p = (
+                Ether(dst=in_if.local_mac, src=in_if.remote_mac)
+                / IP(src=in_if.remote_ip4, dst=out_if.remote_ip4, ttl=64)
+                / TCP(sport=port + i, dport=20)
+            )
             pkts.append(p)
 
         return pkts
 
-    def create_stream_frag(self, src_if, dst, sport, dport, data,
-                           proto=IP_PROTOS.tcp, echo_reply=False):
+    def create_stream_frag(
+        self, src_if, dst, sport, dport, data, proto=IP_PROTOS.tcp, echo_reply=False
+    ):
         if proto == IP_PROTOS.tcp:
-            p = (IP(src=src_if.remote_ip4, dst=dst) /
-                 TCP(sport=sport, dport=dport) /
-                 Raw(data))
+            p = (
+                IP(src=src_if.remote_ip4, dst=dst)
+                / TCP(sport=sport, dport=dport)
+                / Raw(data)
+            )
             p = p.__class__(scapy.compat.raw(p))
             chksum = p[TCP].chksum
             proto_header = TCP(sport=sport, dport=dport, chksum=chksum)
@@ -574,9 +629,9 @@ class TestNAT44ED(VppTestCase):
             proto_header = UDP(sport=sport, dport=dport)
         elif proto == IP_PROTOS.icmp:
             if not echo_reply:
-                proto_header = ICMP(id=sport, type='echo-request')
+                proto_header = ICMP(id=sport, type="echo-request")
             else:
-                proto_header = ICMP(id=sport, type='echo-reply')
+                proto_header = ICMP(id=sport, type="echo-reply")
         else:
             raise Exception("Unsupported protocol")
         id = self.random_port()
@@ -585,33 +640,38 @@ class TestNAT44ED(VppTestCase):
             raw = Raw(data[0:4])
         else:
             raw = Raw(data[0:16])
-        p = (Ether(src=src_if.remote_mac, dst=src_if.local_mac) /
-             IP(src=src_if.remote_ip4, dst=dst, flags="MF", frag=0, id=id) /
-             proto_header /
-             raw)
+        p = (
+            Ether(src=src_if.remote_mac, dst=src_if.local_mac)
+            / IP(src=src_if.remote_ip4, dst=dst, flags="MF", frag=0, id=id)
+            / proto_header
+            / raw
+        )
         pkts.append(p)
         if proto == IP_PROTOS.tcp:
             raw = Raw(data[4:20])
         else:
             raw = Raw(data[16:32])
-        p = (Ether(src=src_if.remote_mac, dst=src_if.local_mac) /
-             IP(src=src_if.remote_ip4, dst=dst, flags="MF", frag=3, id=id,
-                proto=proto) /
-             raw)
+        p = (
+            Ether(src=src_if.remote_mac, dst=src_if.local_mac)
+            / IP(src=src_if.remote_ip4, dst=dst, flags="MF", frag=3, id=id, proto=proto)
+            / raw
+        )
         pkts.append(p)
         if proto == IP_PROTOS.tcp:
             raw = Raw(data[20:])
         else:
             raw = Raw(data[32:])
-        p = (Ether(src=src_if.remote_mac, dst=src_if.local_mac) /
-             IP(src=src_if.remote_ip4, dst=dst, frag=5, proto=proto,
-                id=id) /
-             raw)
+        p = (
+            Ether(src=src_if.remote_mac, dst=src_if.local_mac)
+            / IP(src=src_if.remote_ip4, dst=dst, frag=5, proto=proto, id=id)
+            / raw
+        )
         pkts.append(p)
         return pkts
 
-    def frag_in_order_in_plus_out(self, in_addr, out_addr, in_port, out_port,
-                                  proto=IP_PROTOS.tcp):
+    def frag_in_order_in_plus_out(
+        self, in_addr, out_addr, in_port, out_port, proto=IP_PROTOS.tcp
+    ):
 
         layer = self.proto2layer(proto)
 
@@ -623,16 +683,14 @@ class TestNAT44ED(VppTestCase):
 
         for i in range(2):
             # out2in
-            pkts = self.create_stream_frag(self.pg0, out_addr,
-                                           port_in, out_port,
-                                           data, proto)
+            pkts = self.create_stream_frag(
+                self.pg0, out_addr, port_in, out_port, data, proto
+            )
             self.pg0.add_stream(pkts)
             self.pg_enable_capture(self.pg_interfaces)
             self.pg_start()
             frags = self.pg1.get_capture(len(pkts))
-            p = self.reass_frags_and_verify(frags,
-                                            self.pg0.remote_ip4,
-                                            in_addr)
+            p = self.reass_frags_and_verify(frags, self.pg0.remote_ip4, in_addr)
             if proto != IP_PROTOS.icmp:
                 self.assertEqual(p[layer].sport, port_in)
                 self.assertEqual(p[layer].dport, in_port)
@@ -642,20 +700,24 @@ class TestNAT44ED(VppTestCase):
 
             # in2out
             if proto != IP_PROTOS.icmp:
-                pkts = self.create_stream_frag(self.pg1, self.pg0.remote_ip4,
-                                               in_port,
-                                               p[layer].sport, data, proto)
+                pkts = self.create_stream_frag(
+                    self.pg1, self.pg0.remote_ip4, in_port, p[layer].sport, data, proto
+                )
             else:
-                pkts = self.create_stream_frag(self.pg1, self.pg0.remote_ip4,
-                                               p[layer].id, 0, data, proto,
-                                               echo_reply=True)
+                pkts = self.create_stream_frag(
+                    self.pg1,
+                    self.pg0.remote_ip4,
+                    p[layer].id,
+                    0,
+                    data,
+                    proto,
+                    echo_reply=True,
+                )
             self.pg1.add_stream(pkts)
             self.pg_enable_capture(self.pg_interfaces)
             self.pg_start()
             frags = self.pg0.get_capture(len(pkts))
-            p = self.reass_frags_and_verify(frags,
-                                            out_addr,
-                                            self.pg0.remote_ip4)
+            p = self.reass_frags_and_verify(frags, out_addr, self.pg0.remote_ip4)
             if proto != IP_PROTOS.icmp:
                 self.assertEqual(p[layer].sport, out_port)
                 self.assertEqual(p[layer].dport, port_in)
@@ -663,8 +725,9 @@ class TestNAT44ED(VppTestCase):
                 self.assertEqual(p[layer].id, port_in)
             self.assertEqual(data, p[Raw].load)
 
-    def frag_out_of_order_in_plus_out(self, in_addr, out_addr, in_port,
-                                      out_port, proto=IP_PROTOS.tcp):
+    def frag_out_of_order_in_plus_out(
+        self, in_addr, out_addr, in_port, out_port, proto=IP_PROTOS.tcp
+    ):
 
         layer = self.proto2layer(proto)
 
@@ -676,17 +739,15 @@ class TestNAT44ED(VppTestCase):
 
         for i in range(2):
             # out2in
-            pkts = self.create_stream_frag(self.pg0, out_addr,
-                                           port_in, out_port,
-                                           data, proto)
+            pkts = self.create_stream_frag(
+                self.pg0, out_addr, port_in, out_port, data, proto
+            )
             pkts.reverse()
             self.pg0.add_stream(pkts)
             self.pg_enable_capture(self.pg_interfaces)
             self.pg_start()
             frags = self.pg1.get_capture(len(pkts))
-            p = self.reass_frags_and_verify(frags,
-                                            self.pg0.remote_ip4,
-                                            in_addr)
+            p = self.reass_frags_and_verify(frags, self.pg0.remote_ip4, in_addr)
             if proto != IP_PROTOS.icmp:
                 self.assertEqual(p[layer].dport, in_port)
                 self.assertEqual(p[layer].sport, port_in)
@@ -697,21 +758,25 @@ class TestNAT44ED(VppTestCase):
 
             # in2out
             if proto != IP_PROTOS.icmp:
-                pkts = self.create_stream_frag(self.pg1, self.pg0.remote_ip4,
-                                               in_port,
-                                               p[layer].sport, data, proto)
+                pkts = self.create_stream_frag(
+                    self.pg1, self.pg0.remote_ip4, in_port, p[layer].sport, data, proto
+                )
             else:
-                pkts = self.create_stream_frag(self.pg1, self.pg0.remote_ip4,
-                                               p[layer].id, 0, data, proto,
-                                               echo_reply=True)
+                pkts = self.create_stream_frag(
+                    self.pg1,
+                    self.pg0.remote_ip4,
+                    p[layer].id,
+                    0,
+                    data,
+                    proto,
+                    echo_reply=True,
+                )
             pkts.reverse()
             self.pg1.add_stream(pkts)
             self.pg_enable_capture(self.pg_interfaces)
             self.pg_start()
             frags = self.pg0.get_capture(len(pkts))
-            p = self.reass_frags_and_verify(frags,
-                                            out_addr,
-                                            self.pg0.remote_ip4)
+            p = self.reass_frags_and_verify(frags, out_addr, self.pg0.remote_ip4)
             if proto != IP_PROTOS.icmp:
                 self.assertEqual(p[layer].sport, out_port)
                 self.assertEqual(p[layer].dport, port_in)
@@ -721,9 +786,11 @@ class TestNAT44ED(VppTestCase):
 
     def init_tcp_session(self, in_if, out_if, in_port, ext_port):
         # SYN packet in->out
-        p = (Ether(src=in_if.remote_mac, dst=in_if.local_mac) /
-             IP(src=in_if.remote_ip4, dst=out_if.remote_ip4) /
-             TCP(sport=in_port, dport=ext_port, flags="S"))
+        p = (
+            Ether(src=in_if.remote_mac, dst=in_if.local_mac)
+            / IP(src=in_if.remote_ip4, dst=out_if.remote_ip4)
+            / TCP(sport=in_port, dport=ext_port, flags="S")
+        )
         in_if.add_stream(p)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
@@ -732,18 +799,22 @@ class TestNAT44ED(VppTestCase):
         out_port = p[TCP].sport
 
         # SYN + ACK packet out->in
-        p = (Ether(src=out_if.remote_mac, dst=out_if.local_mac) /
-             IP(src=out_if.remote_ip4, dst=self.nat_addr) /
-             TCP(sport=ext_port, dport=out_port, flags="SA"))
+        p = (
+            Ether(src=out_if.remote_mac, dst=out_if.local_mac)
+            / IP(src=out_if.remote_ip4, dst=self.nat_addr)
+            / TCP(sport=ext_port, dport=out_port, flags="SA")
+        )
         out_if.add_stream(p)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
         in_if.get_capture(1)
 
         # ACK packet in->out
-        p = (Ether(src=in_if.remote_mac, dst=in_if.local_mac) /
-             IP(src=in_if.remote_ip4, dst=out_if.remote_ip4) /
-             TCP(sport=in_port, dport=ext_port, flags="A"))
+        p = (
+            Ether(src=in_if.remote_mac, dst=in_if.local_mac)
+            / IP(src=in_if.remote_ip4, dst=out_if.remote_ip4)
+            / TCP(sport=in_port, dport=ext_port, flags="A")
+        )
         in_if.add_stream(p)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
@@ -751,9 +822,10 @@ class TestNAT44ED(VppTestCase):
 
         return out_port
 
-    def twice_nat_common(self, self_twice_nat=False, same_pg=False, lb=False,
-                         client_id=None):
-        twice_nat_addr = '10.0.1.3'
+    def twice_nat_common(
+        self, self_twice_nat=False, same_pg=False, lb=False, client_id=None
+    ):
+        twice_nat_addr = "10.0.1.3"
 
         port_in = 8080
         if lb:
@@ -780,8 +852,7 @@ class TestNAT44ED(VppTestCase):
         else:
             pg1 = self.pg1
 
-        eh_translate = ((not self_twice_nat) or (not lb and same_pg) or
-                        client_id == 1)
+        eh_translate = (not self_twice_nat) or (not lb and same_pg) or client_id == 1
 
         self.nat_add_address(self.nat_addr)
         self.nat_add_address(twice_nat_addr, twice_nat=1)
@@ -793,27 +864,30 @@ class TestNAT44ED(VppTestCase):
             flags |= self.config_flags.NAT_IS_TWICE_NAT
 
         if not lb:
-            self.nat_add_static_mapping(pg0.remote_ip4, self.nat_addr,
-                                        port_in, port_out,
-                                        proto=IP_PROTOS.tcp,
-                                        flags=flags)
+            self.nat_add_static_mapping(
+                pg0.remote_ip4,
+                self.nat_addr,
+                port_in,
+                port_out,
+                proto=IP_PROTOS.tcp,
+                flags=flags,
+            )
         else:
-            locals = [{'addr': server1.ip4,
-                       'port': port_in1,
-                       'probability': 50,
-                       'vrf_id': 0},
-                      {'addr': server2.ip4,
-                       'port': port_in2,
-                       'probability': 50,
-                       'vrf_id': 0}]
+            locals = [
+                {"addr": server1.ip4, "port": port_in1, "probability": 50, "vrf_id": 0},
+                {"addr": server2.ip4, "port": port_in2, "probability": 50, "vrf_id": 0},
+            ]
             out_addr = self.nat_addr
 
-            self.vapi.nat44_add_del_lb_static_mapping(is_add=1, flags=flags,
-                                                      external_addr=out_addr,
-                                                      external_port=port_out,
-                                                      protocol=IP_PROTOS.tcp,
-                                                      local_num=len(locals),
-                                                      locals=locals)
+            self.vapi.nat44_add_del_lb_static_mapping(
+                is_add=1,
+                flags=flags,
+                external_addr=out_addr,
+                external_port=port_out,
+                protocol=IP_PROTOS.tcp,
+                local_num=len(locals),
+                locals=locals,
+            )
         self.nat_add_inside_interface(pg0)
         self.nat_add_outside_interface(pg1)
 
@@ -828,9 +902,11 @@ class TestNAT44ED(VppTestCase):
                     client = self.pg0.remote_hosts[1]
         else:
             client = pg1.remote_hosts[0]
-        p = (Ether(src=pg1.remote_mac, dst=pg1.local_mac) /
-             IP(src=client.ip4, dst=self.nat_addr) /
-             TCP(sport=eh_port_out, dport=port_out))
+        p = (
+            Ether(src=pg1.remote_mac, dst=pg1.local_mac)
+            / IP(src=client.ip4, dst=self.nat_addr)
+            / TCP(sport=eh_port_out, dport=port_out)
+        )
         pg1.add_stream(p)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
@@ -865,9 +941,11 @@ class TestNAT44ED(VppTestCase):
             self.logger.error(ppp("Unexpected or invalid packet:", p))
             raise
 
-        p = (Ether(src=server.mac, dst=pg0.local_mac) /
-             IP(src=server.ip4, dst=eh_addr_in) /
-             TCP(sport=saved_port_in, dport=eh_port_in))
+        p = (
+            Ether(src=server.mac, dst=pg0.local_mac)
+            / IP(src=server.ip4, dst=eh_addr_in)
+            / TCP(sport=saved_port_in, dport=eh_port_in)
+        )
         pg0.add_stream(p)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
@@ -888,24 +966,25 @@ class TestNAT44ED(VppTestCase):
         if eh_translate:
             sessions = self.vapi.nat44_user_session_dump(server.ip4, 0)
             self.assertEqual(len(sessions), 1)
-            self.assertTrue(sessions[0].flags &
-                            self.config_flags.NAT_IS_EXT_HOST_VALID)
-            self.assertTrue(sessions[0].flags &
-                            self.config_flags.NAT_IS_TWICE_NAT)
+            self.assertTrue(sessions[0].flags & self.config_flags.NAT_IS_EXT_HOST_VALID)
+            self.assertTrue(sessions[0].flags & self.config_flags.NAT_IS_TWICE_NAT)
             self.logger.info(self.vapi.cli("show nat44 sessions"))
             self.vapi.nat44_del_session(
                 address=sessions[0].inside_ip_address,
                 port=sessions[0].inside_port,
                 protocol=sessions[0].protocol,
-                flags=(self.config_flags.NAT_IS_INSIDE |
-                       self.config_flags.NAT_IS_EXT_HOST_VALID),
+                flags=(
+                    self.config_flags.NAT_IS_INSIDE
+                    | self.config_flags.NAT_IS_EXT_HOST_VALID
+                ),
                 ext_host_address=sessions[0].ext_host_nat_address,
-                ext_host_port=sessions[0].ext_host_nat_port)
+                ext_host_port=sessions[0].ext_host_nat_port,
+            )
             sessions = self.vapi.nat44_user_session_dump(server.ip4, 0)
             self.assertEqual(len(sessions), 0)
 
     def verify_syslog_sess(self, data, msgid, is_ip6=False):
-        message = data.decode('utf-8')
+        message = data.decode("utf-8")
         try:
             message = SyslogMessage.parse(message)
         except ParseError as e:
@@ -913,29 +992,28 @@ class TestNAT44ED(VppTestCase):
             raise
         else:
             self.assertEqual(message.severity, SyslogSeverity.info)
-            self.assertEqual(message.appname, 'NAT')
+            self.assertEqual(message.appname, "NAT")
             self.assertEqual(message.msgid, msgid)
-            sd_params = message.sd.get('nsess')
+            sd_params = message.sd.get("nsess")
             self.assertTrue(sd_params is not None)
             if is_ip6:
-                self.assertEqual(sd_params.get('IATYP'), 'IPv6')
-                self.assertEqual(sd_params.get('ISADDR'), self.pg0.remote_ip6)
+                self.assertEqual(sd_params.get("IATYP"), "IPv6")
+                self.assertEqual(sd_params.get("ISADDR"), self.pg0.remote_ip6)
             else:
-                self.assertEqual(sd_params.get('IATYP'), 'IPv4')
-                self.assertEqual(sd_params.get('ISADDR'), self.pg0.remote_ip4)
-                self.assertTrue(sd_params.get('SSUBIX') is not None)
-            self.assertEqual(sd_params.get('ISPORT'), "%d" % self.tcp_port_in)
-            self.assertEqual(sd_params.get('XATYP'), 'IPv4')
-            self.assertEqual(sd_params.get('XSADDR'), self.nat_addr)
-            self.assertEqual(sd_params.get('XSPORT'), "%d" % self.tcp_port_out)
-            self.assertEqual(sd_params.get('PROTO'), "%d" % IP_PROTOS.tcp)
-            self.assertEqual(sd_params.get('SVLAN'), '0')
-            self.assertEqual(sd_params.get('XDADDR'), self.pg1.remote_ip4)
-            self.assertEqual(sd_params.get('XDPORT'),
-                             "%d" % self.tcp_external_port)
+                self.assertEqual(sd_params.get("IATYP"), "IPv4")
+                self.assertEqual(sd_params.get("ISADDR"), self.pg0.remote_ip4)
+                self.assertTrue(sd_params.get("SSUBIX") is not None)
+            self.assertEqual(sd_params.get("ISPORT"), "%d" % self.tcp_port_in)
+            self.assertEqual(sd_params.get("XATYP"), "IPv4")
+            self.assertEqual(sd_params.get("XSADDR"), self.nat_addr)
+            self.assertEqual(sd_params.get("XSPORT"), "%d" % self.tcp_port_out)
+            self.assertEqual(sd_params.get("PROTO"), "%d" % IP_PROTOS.tcp)
+            self.assertEqual(sd_params.get("SVLAN"), "0")
+            self.assertEqual(sd_params.get("XDADDR"), self.pg1.remote_ip4)
+            self.assertEqual(sd_params.get("XDPORT"), "%d" % self.tcp_external_port)
 
     def test_icmp_error(self):
-        """ NAT44ED test ICMP error message with inner header"""
+        """NAT44ED test ICMP error message with inner header"""
 
         payload = "H" * 10
 
@@ -944,25 +1022,31 @@ class TestNAT44ED(VppTestCase):
         self.nat_add_outside_interface(self.pg1)
 
         # in2out (initiate connection)
-        p1 = [Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
-              IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
-              UDP(sport=21, dport=20) / payload,
-              Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
-              IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
-              TCP(sport=21, dport=20, flags="S") / payload,
-              Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
-              IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
-              ICMP(type='echo-request', id=7777) / payload,
-              ]
+        p1 = [
+            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+            / IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4)
+            / UDP(sport=21, dport=20)
+            / payload,
+            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+            / IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4)
+            / TCP(sport=21, dport=20, flags="S")
+            / payload,
+            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+            / IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4)
+            / ICMP(type="echo-request", id=7777)
+            / payload,
+        ]
 
         capture = self.send_and_expect(self.pg0, p1, self.pg1)
 
         # out2in (send error message)
-        p2 = [Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac) /
-              IP(src=self.pg1.remote_ip4, dst=self.nat_addr) /
-              ICMP(type='dest-unreach', code='port-unreachable') /
-              c[IP:]
-              for c in capture]
+        p2 = [
+            Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac)
+            / IP(src=self.pg1.remote_ip4, dst=self.nat_addr)
+            / ICMP(type="dest-unreach", code="port-unreachable")
+            / c[IP:]
+            for c in capture
+        ]
 
         capture = self.send_and_expect(self.pg1, p2, self.pg0)
 
@@ -971,20 +1055,21 @@ class TestNAT44ED(VppTestCase):
                 assert c[IP].dst == self.pg0.remote_ip4
                 assert c[IPerror].src == self.pg0.remote_ip4
             except AssertionError as a:
-                raise AssertionError(
-                    f"Packet {pr(c)} not translated properly") from a
+                raise AssertionError(f"Packet {pr(c)} not translated properly") from a
 
     def test_icmp_echo_reply_trailer(self):
-        """ ICMP echo reply with ethernet trailer"""
+        """ICMP echo reply with ethernet trailer"""
 
         self.nat_add_address(self.nat_addr)
         self.nat_add_inside_interface(self.pg0)
         self.nat_add_outside_interface(self.pg1)
 
         # in2out
-        p1 = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
-              IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
-              ICMP(type=8, id=0xabcd, seq=0))
+        p1 = (
+            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+            / IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4)
+            / ICMP(type=8, id=0xABCD, seq=0)
+        )
 
         self.pg0.add_stream(p1)
         self.pg_enable_capture(self.pg_interfaces)
@@ -994,9 +1079,11 @@ class TestNAT44ED(VppTestCase):
         self.logger.debug(self.vapi.cli("show trace"))
 
         # out2in
-        p2 = (Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac) /
-              IP(src=self.pg1.remote_ip4, dst=self.nat_addr, id=0xee59) /
-              ICMP(type=0, id=c[ICMP].id, seq=0))
+        p2 = (
+            Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac)
+            / IP(src=self.pg1.remote_ip4, dst=self.nat_addr, id=0xEE59)
+            / ICMP(type=0, id=c[ICMP].id, seq=0)
+        )
 
         # force checksum calculation
         p2 = p2.__class__(bytes(p2))
@@ -1019,7 +1106,7 @@ class TestNAT44ED(VppTestCase):
         self.pg0.get_capture(1)
 
     def test_users_dump(self):
-        """ NAT44ED API test - nat44_user_dump """
+        """NAT44ED API test - nat44_user_dump"""
 
         self.nat_add_address(self.nat_addr)
         self.nat_add_inside_interface(self.pg0)
@@ -1061,9 +1148,9 @@ class TestNAT44ED(VppTestCase):
         host0 = self.pg0.remote_hosts[0]
         self.pg0.remote_hosts[0] = self.pg0.remote_hosts[1]
         try:
-            pkts = self.create_stream_out(self.pg1,
-                                          dst_ip=self.pg0.remote_ip4,
-                                          use_inside_ports=True)
+            pkts = self.create_stream_out(
+                self.pg1, dst_ip=self.pg0.remote_ip4, use_inside_ports=True
+            )
             self.pg1.add_stream(pkts)
             self.pg_enable_capture(self.pg_interfaces)
             self.pg_start()
@@ -1075,8 +1162,7 @@ class TestNAT44ED(VppTestCase):
             self.pg_enable_capture(self.pg_interfaces)
             self.pg_start()
             capture = self.pg1.get_capture(len(pkts))
-            self.verify_capture_out(capture, nat_ip=self.pg0.remote_ip4,
-                                    same_port=True)
+            self.verify_capture_out(capture, nat_ip=self.pg0.remote_ip4, same_port=True)
         finally:
             self.pg0.remote_hosts[0] = host0
 
@@ -1107,14 +1193,14 @@ class TestNAT44ED(VppTestCase):
         self.assertEqual(non_static_user.nsessions, 3)
 
     def test_frag_out_of_order_do_not_translate(self):
-        """ NAT44ED don't translate fragments arriving out of order """
+        """NAT44ED don't translate fragments arriving out of order"""
         self.nat_add_inside_interface(self.pg0)
         self.nat_add_outside_interface(self.pg1)
         self.vapi.nat44_forwarding_enable_disable(enable=True)
         self.frag_out_of_order(proto=IP_PROTOS.tcp, dont_translate=True)
 
     def test_forwarding(self):
-        """ NAT44ED forwarding test """
+        """NAT44ED forwarding test"""
 
         self.nat_add_inside_interface(self.pg0)
         self.nat_add_outside_interface(self.pg1)
@@ -1123,11 +1209,13 @@ class TestNAT44ED(VppTestCase):
         real_ip = self.pg0.remote_ip4
         alias_ip = self.nat_addr
         flags = self.config_flags.NAT_IS_ADDR_ONLY
-        self.vapi.nat44_add_del_static_mapping(is_add=1,
-                                               local_ip_address=real_ip,
-                                               external_ip_address=alias_ip,
-                                               external_sw_if_index=0xFFFFFFFF,
-                                               flags=flags)
+        self.vapi.nat44_add_del_static_mapping(
+            is_add=1,
+            local_ip_address=real_ip,
+            external_ip_address=alias_ip,
+            external_sw_if_index=0xFFFFFFFF,
+            flags=flags,
+        )
 
         try:
             # in2out - static mapping match
@@ -1151,9 +1239,9 @@ class TestNAT44ED(VppTestCase):
             host0 = self.pg0.remote_hosts[0]
             self.pg0.remote_hosts[0] = self.pg0.remote_hosts[1]
             try:
-                pkts = self.create_stream_out(self.pg1,
-                                              dst_ip=self.pg0.remote_ip4,
-                                              use_inside_ports=True)
+                pkts = self.create_stream_out(
+                    self.pg1, dst_ip=self.pg0.remote_ip4, use_inside_ports=True
+                )
                 self.pg1.add_stream(pkts)
                 self.pg_enable_capture(self.pg_interfaces)
                 self.pg_start()
@@ -1165,24 +1253,27 @@ class TestNAT44ED(VppTestCase):
                 self.pg_enable_capture(self.pg_interfaces)
                 self.pg_start()
                 capture = self.pg1.get_capture(len(pkts))
-                self.verify_capture_out(capture, nat_ip=self.pg0.remote_ip4,
-                                        same_port=True)
+                self.verify_capture_out(
+                    capture, nat_ip=self.pg0.remote_ip4, same_port=True
+                )
             finally:
                 self.pg0.remote_hosts[0] = host0
 
             user = self.pg0.remote_hosts[1]
             sessions = self.vapi.nat44_user_session_dump(user.ip4, 0)
             self.assertEqual(len(sessions), 3)
-            self.assertTrue(sessions[0].flags &
-                            self.config_flags.NAT_IS_EXT_HOST_VALID)
+            self.assertTrue(sessions[0].flags & self.config_flags.NAT_IS_EXT_HOST_VALID)
             self.vapi.nat44_del_session(
                 address=sessions[0].inside_ip_address,
                 port=sessions[0].inside_port,
                 protocol=sessions[0].protocol,
-                flags=(self.config_flags.NAT_IS_INSIDE |
-                       self.config_flags.NAT_IS_EXT_HOST_VALID),
+                flags=(
+                    self.config_flags.NAT_IS_INSIDE
+                    | self.config_flags.NAT_IS_EXT_HOST_VALID
+                ),
                 ext_host_address=sessions[0].ext_host_address,
-                ext_host_port=sessions[0].ext_host_port)
+                ext_host_port=sessions[0].ext_host_port,
+            )
             sessions = self.vapi.nat44_user_session_dump(user.ip4, 0)
             self.assertEqual(len(sessions), 2)
 
@@ -1194,16 +1285,17 @@ class TestNAT44ED(VppTestCase):
                 local_ip_address=real_ip,
                 external_ip_address=alias_ip,
                 external_sw_if_index=0xFFFFFFFF,
-                flags=flags)
+                flags=flags,
+            )
 
     def test_output_feature_and_service2(self):
-        """ NAT44ED interface output feature and service host direct access """
+        """NAT44ED interface output feature and service host direct access"""
         self.vapi.nat44_forwarding_enable_disable(enable=1)
         self.nat_add_address(self.nat_addr)
 
         self.vapi.nat44_ed_add_del_output_interface(
-            sw_if_index=self.pg1.sw_if_index,
-            is_add=1)
+            sw_if_index=self.pg1.sw_if_index, is_add=1
+        )
 
         # session initiated from service host - translate
         pkts = self.create_stream_in(self.pg0, self.pg1)
@@ -1230,9 +1322,9 @@ class TestNAT44ED(VppTestCase):
         self.icmp_id_in = 60305
 
         try:
-            pkts = self.create_stream_out(self.pg1,
-                                          self.pg0.remote_ip4,
-                                          use_inside_ports=True)
+            pkts = self.create_stream_out(
+                self.pg1, self.pg0.remote_ip4, use_inside_ports=True
+            )
             self.pg1.add_stream(pkts)
             self.pg_enable_capture(self.pg_interfaces)
             self.pg_start()
@@ -1244,40 +1336,37 @@ class TestNAT44ED(VppTestCase):
             self.pg_enable_capture(self.pg_interfaces)
             self.pg_start()
             capture = self.pg1.get_capture(len(pkts))
-            self.verify_capture_out(capture, nat_ip=self.pg0.remote_ip4,
-                                    same_port=True)
+            self.verify_capture_out(capture, nat_ip=self.pg0.remote_ip4, same_port=True)
         finally:
             self.tcp_port_in = tcp_port_in
             self.udp_port_in = udp_port_in
             self.icmp_id_in = icmp_id_in
 
     def test_twice_nat(self):
-        """ NAT44ED Twice NAT """
+        """NAT44ED Twice NAT"""
         self.twice_nat_common()
 
     def test_self_twice_nat_positive(self):
-        """ NAT44ED Self Twice NAT (positive test) """
+        """NAT44ED Self Twice NAT (positive test)"""
         self.twice_nat_common(self_twice_nat=True, same_pg=True)
 
     def test_self_twice_nat_lb_positive(self):
-        """ NAT44ED Self Twice NAT local service load balancing (positive test)
-        """
-        self.twice_nat_common(lb=True, self_twice_nat=True, same_pg=True,
-                              client_id=1)
+        """NAT44ED Self Twice NAT local service load balancing (positive test)"""
+        self.twice_nat_common(lb=True, self_twice_nat=True, same_pg=True, client_id=1)
 
     def test_twice_nat_lb(self):
-        """ NAT44ED Twice NAT local service load balancing """
+        """NAT44ED Twice NAT local service load balancing"""
         self.twice_nat_common(lb=True)
 
     def test_output_feature(self):
-        """ NAT44ED interface output feature (in2out postrouting) """
+        """NAT44ED interface output feature (in2out postrouting)"""
         self.vapi.nat44_forwarding_enable_disable(enable=1)
         self.nat_add_address(self.nat_addr)
 
         self.nat_add_outside_interface(self.pg0)
         self.vapi.nat44_ed_add_del_output_interface(
-            sw_if_index=self.pg1.sw_if_index,
-            is_add=1)
+            sw_if_index=self.pg1.sw_if_index, is_add=1
+        )
 
         # in2out
         pkts = self.create_stream_in(self.pg0, self.pg1)
@@ -1323,24 +1412,31 @@ class TestNAT44ED(VppTestCase):
             self.assertEqual(p[ICMP].type, 11)  # 11 == time-exceeded
 
     def test_static_with_port_out2(self):
-        """ NAT44ED 1:1 NAPT asymmetrical rule """
+        """NAT44ED 1:1 NAPT asymmetrical rule"""
 
         external_port = 80
         local_port = 8080
 
         self.vapi.nat44_forwarding_enable_disable(enable=1)
         flags = self.config_flags.NAT_IS_OUT2IN_ONLY
-        self.nat_add_static_mapping(self.pg0.remote_ip4, self.nat_addr,
-                                    local_port, external_port,
-                                    proto=IP_PROTOS.tcp, flags=flags)
+        self.nat_add_static_mapping(
+            self.pg0.remote_ip4,
+            self.nat_addr,
+            local_port,
+            external_port,
+            proto=IP_PROTOS.tcp,
+            flags=flags,
+        )
 
         self.nat_add_inside_interface(self.pg0)
         self.nat_add_outside_interface(self.pg1)
 
         # from client to service
-        p = (Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac) /
-             IP(src=self.pg1.remote_ip4, dst=self.nat_addr) /
-             TCP(sport=12345, dport=external_port))
+        p = (
+            Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac)
+            / IP(src=self.pg1.remote_ip4, dst=self.nat_addr)
+            / TCP(sport=12345, dport=external_port)
+        )
         self.pg1.add_stream(p)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
@@ -1357,9 +1453,12 @@ class TestNAT44ED(VppTestCase):
             raise
 
         # ICMP error
-        p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
-             IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
-             ICMP(type=11) / capture[0][IP])
+        p = (
+            Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac)
+            / IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4)
+            / ICMP(type=11)
+            / capture[0][IP]
+        )
         self.pg0.add_stream(p)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
@@ -1375,9 +1474,11 @@ class TestNAT44ED(VppTestCase):
             raise
 
         # from service back to client
-        p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
-             IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
-             TCP(sport=local_port, dport=12345))
+        p = (
+            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+            / IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4)
+            / TCP(sport=local_port, dport=12345)
+        )
         self.pg0.add_stream(p)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
@@ -1394,9 +1495,12 @@ class TestNAT44ED(VppTestCase):
             raise
 
         # ICMP error
-        p = (Ether(dst=self.pg1.local_mac, src=self.pg1.remote_mac) /
-             IP(src=self.pg1.remote_ip4, dst=self.nat_addr) /
-             ICMP(type=11) / capture[0][IP])
+        p = (
+            Ether(dst=self.pg1.local_mac, src=self.pg1.remote_mac)
+            / IP(src=self.pg1.remote_ip4, dst=self.nat_addr)
+            / ICMP(type=11)
+            / capture[0][IP]
+        )
         self.pg1.add_stream(p)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
@@ -1412,9 +1516,11 @@ class TestNAT44ED(VppTestCase):
             raise
 
         # from client to server (no translation)
-        p = (Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac) /
-             IP(src=self.pg1.remote_ip4, dst=self.pg0.remote_ip4) /
-             TCP(sport=12346, dport=local_port))
+        p = (
+            Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac)
+            / IP(src=self.pg1.remote_ip4, dst=self.pg0.remote_ip4)
+            / TCP(sport=12346, dport=local_port)
+        )
         self.pg1.add_stream(p)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
@@ -1431,9 +1537,11 @@ class TestNAT44ED(VppTestCase):
             raise
 
         # from service back to client (no translation)
-        p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
-             IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
-             TCP(sport=local_port, dport=12346))
+        p = (
+            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+            / IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4)
+            / TCP(sport=local_port, dport=12346)
+        )
         self.pg0.add_stream(p)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
@@ -1450,21 +1558,17 @@ class TestNAT44ED(VppTestCase):
             raise
 
     def test_static_lb(self):
-        """ NAT44ED local service load balancing """
+        """NAT44ED local service load balancing"""
         external_addr_n = self.nat_addr
         external_port = 80
         local_port = 8080
         server1 = self.pg0.remote_hosts[0]
         server2 = self.pg0.remote_hosts[1]
 
-        locals = [{'addr': server1.ip4,
-                   'port': local_port,
-                   'probability': 70,
-                   'vrf_id': 0},
-                  {'addr': server2.ip4,
-                   'port': local_port,
-                   'probability': 30,
-                   'vrf_id': 0}]
+        locals = [
+            {"addr": server1.ip4, "port": local_port, "probability": 70, "vrf_id": 0},
+            {"addr": server2.ip4, "port": local_port, "probability": 30, "vrf_id": 0},
+        ]
 
         self.nat_add_address(self.nat_addr)
         self.vapi.nat44_add_del_lb_static_mapping(
@@ -1473,19 +1577,22 @@ class TestNAT44ED(VppTestCase):
             external_port=external_port,
             protocol=IP_PROTOS.tcp,
             local_num=len(locals),
-            locals=locals)
+            locals=locals,
+        )
         flags = self.config_flags.NAT_IS_INSIDE
         self.vapi.nat44_interface_add_del_feature(
-            sw_if_index=self.pg0.sw_if_index,
-            flags=flags, is_add=1)
+            sw_if_index=self.pg0.sw_if_index, flags=flags, is_add=1
+        )
         self.vapi.nat44_interface_add_del_feature(
-            sw_if_index=self.pg1.sw_if_index,
-            is_add=1)
+            sw_if_index=self.pg1.sw_if_index, is_add=1
+        )
 
         # from client to service
-        p = (Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac) /
-             IP(src=self.pg1.remote_ip4, dst=self.nat_addr) /
-             TCP(sport=12345, dport=external_port))
+        p = (
+            Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac)
+            / IP(src=self.pg1.remote_ip4, dst=self.nat_addr)
+            / TCP(sport=12345, dport=external_port)
+        )
         self.pg1.add_stream(p)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
@@ -1507,9 +1614,11 @@ class TestNAT44ED(VppTestCase):
             raise
 
         # from service back to client
-        p = (Ether(src=server.mac, dst=self.pg0.local_mac) /
-             IP(src=server.ip4, dst=self.pg1.remote_ip4) /
-             TCP(sport=local_port, dport=12345))
+        p = (
+            Ether(src=server.mac, dst=self.pg0.local_mac)
+            / IP(src=server.ip4, dst=self.pg1.remote_ip4)
+            / TCP(sport=local_port, dport=12345)
+        )
         self.pg0.add_stream(p)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
@@ -1527,56 +1636,59 @@ class TestNAT44ED(VppTestCase):
 
         sessions = self.vapi.nat44_user_session_dump(server.ip4, 0)
         self.assertEqual(len(sessions), 1)
-        self.assertTrue(sessions[0].flags &
-                        self.config_flags.NAT_IS_EXT_HOST_VALID)
+        self.assertTrue(sessions[0].flags & self.config_flags.NAT_IS_EXT_HOST_VALID)
         self.vapi.nat44_del_session(
             address=sessions[0].inside_ip_address,
             port=sessions[0].inside_port,
             protocol=sessions[0].protocol,
-            flags=(self.config_flags.NAT_IS_INSIDE |
-                   self.config_flags.NAT_IS_EXT_HOST_VALID),
+            flags=(
+                self.config_flags.NAT_IS_INSIDE
+                | self.config_flags.NAT_IS_EXT_HOST_VALID
+            ),
             ext_host_address=sessions[0].ext_host_address,
-            ext_host_port=sessions[0].ext_host_port)
+            ext_host_port=sessions[0].ext_host_port,
+        )
         sessions = self.vapi.nat44_user_session_dump(server.ip4, 0)
         self.assertEqual(len(sessions), 0)
 
     def test_static_lb_2(self):
-        """ NAT44ED local service load balancing (asymmetrical rule) """
+        """NAT44ED local service load balancing (asymmetrical rule)"""
         external_addr = self.nat_addr
         external_port = 80
         local_port = 8080
         server1 = self.pg0.remote_hosts[0]
         server2 = self.pg0.remote_hosts[1]
 
-        locals = [{'addr': server1.ip4,
-                   'port': local_port,
-                   'probability': 70,
-                   'vrf_id': 0},
-                  {'addr': server2.ip4,
-                   'port': local_port,
-                   'probability': 30,
-                   'vrf_id': 0}]
+        locals = [
+            {"addr": server1.ip4, "port": local_port, "probability": 70, "vrf_id": 0},
+            {"addr": server2.ip4, "port": local_port, "probability": 30, "vrf_id": 0},
+        ]
 
         self.vapi.nat44_forwarding_enable_disable(enable=1)
         flags = self.config_flags.NAT_IS_OUT2IN_ONLY
-        self.vapi.nat44_add_del_lb_static_mapping(is_add=1, flags=flags,
-                                                  external_addr=external_addr,
-                                                  external_port=external_port,
-                                                  protocol=IP_PROTOS.tcp,
-                                                  local_num=len(locals),
-                                                  locals=locals)
+        self.vapi.nat44_add_del_lb_static_mapping(
+            is_add=1,
+            flags=flags,
+            external_addr=external_addr,
+            external_port=external_port,
+            protocol=IP_PROTOS.tcp,
+            local_num=len(locals),
+            locals=locals,
+        )
         flags = self.config_flags.NAT_IS_INSIDE
         self.vapi.nat44_interface_add_del_feature(
-            sw_if_index=self.pg0.sw_if_index,
-            flags=flags, is_add=1)
+            sw_if_index=self.pg0.sw_if_index, flags=flags, is_add=1
+        )
         self.vapi.nat44_interface_add_del_feature(
-            sw_if_index=self.pg1.sw_if_index,
-            is_add=1)
+            sw_if_index=self.pg1.sw_if_index, is_add=1
+        )
 
         # from client to service
-        p = (Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac) /
-             IP(src=self.pg1.remote_ip4, dst=self.nat_addr) /
-             TCP(sport=12345, dport=external_port))
+        p = (
+            Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac)
+            / IP(src=self.pg1.remote_ip4, dst=self.nat_addr)
+            / TCP(sport=12345, dport=external_port)
+        )
         self.pg1.add_stream(p)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
@@ -1598,9 +1710,11 @@ class TestNAT44ED(VppTestCase):
             raise
 
         # from service back to client
-        p = (Ether(src=server.mac, dst=self.pg0.local_mac) /
-             IP(src=server.ip4, dst=self.pg1.remote_ip4) /
-             TCP(sport=local_port, dport=12345))
+        p = (
+            Ether(src=server.mac, dst=self.pg0.local_mac)
+            / IP(src=server.ip4, dst=self.pg1.remote_ip4)
+            / TCP(sport=local_port, dport=12345)
+        )
         self.pg0.add_stream(p)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
@@ -1617,9 +1731,11 @@ class TestNAT44ED(VppTestCase):
             raise
 
         # from client to server (no translation)
-        p = (Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac) /
-             IP(src=self.pg1.remote_ip4, dst=server1.ip4) /
-             TCP(sport=12346, dport=local_port))
+        p = (
+            Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac)
+            / IP(src=self.pg1.remote_ip4, dst=server1.ip4)
+            / TCP(sport=12346, dport=local_port)
+        )
         self.pg1.add_stream(p)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
@@ -1637,9 +1753,11 @@ class TestNAT44ED(VppTestCase):
             raise
 
         # from service back to client (no translation)
-        p = (Ether(src=server1.mac, dst=self.pg0.local_mac) /
-             IP(src=server1.ip4, dst=self.pg1.remote_ip4) /
-             TCP(sport=local_port, dport=12346))
+        p = (
+            Ether(src=server1.mac, dst=self.pg0.local_mac)
+            / IP(src=server1.ip4, dst=self.pg1.remote_ip4)
+            / TCP(sport=local_port, dport=12346)
+        )
         self.pg0.add_stream(p)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
@@ -1656,41 +1774,41 @@ class TestNAT44ED(VppTestCase):
             raise
 
     def test_lb_affinity(self):
-        """ NAT44ED local service load balancing affinity """
+        """NAT44ED local service load balancing affinity"""
         external_addr = self.nat_addr
         external_port = 80
         local_port = 8080
         server1 = self.pg0.remote_hosts[0]
         server2 = self.pg0.remote_hosts[1]
 
-        locals = [{'addr': server1.ip4,
-                   'port': local_port,
-                   'probability': 50,
-                   'vrf_id': 0},
-                  {'addr': server2.ip4,
-                   'port': local_port,
-                   'probability': 50,
-                   'vrf_id': 0}]
+        locals = [
+            {"addr": server1.ip4, "port": local_port, "probability": 50, "vrf_id": 0},
+            {"addr": server2.ip4, "port": local_port, "probability": 50, "vrf_id": 0},
+        ]
 
         self.nat_add_address(self.nat_addr)
-        self.vapi.nat44_add_del_lb_static_mapping(is_add=1,
-                                                  external_addr=external_addr,
-                                                  external_port=external_port,
-                                                  protocol=IP_PROTOS.tcp,
-                                                  affinity=10800,
-                                                  local_num=len(locals),
-                                                  locals=locals)
+        self.vapi.nat44_add_del_lb_static_mapping(
+            is_add=1,
+            external_addr=external_addr,
+            external_port=external_port,
+            protocol=IP_PROTOS.tcp,
+            affinity=10800,
+            local_num=len(locals),
+            locals=locals,
+        )
         flags = self.config_flags.NAT_IS_INSIDE
         self.vapi.nat44_interface_add_del_feature(
-            sw_if_index=self.pg0.sw_if_index,
-            flags=flags, is_add=1)
+            sw_if_index=self.pg0.sw_if_index, flags=flags, is_add=1
+        )
         self.vapi.nat44_interface_add_del_feature(
-            sw_if_index=self.pg1.sw_if_index,
-            is_add=1)
+            sw_if_index=self.pg1.sw_if_index, is_add=1
+        )
 
-        p = (Ether(dst=self.pg1.local_mac, src=self.pg1.remote_mac) /
-             IP(src=self.pg1.remote_ip4, dst=self.nat_addr) /
-             TCP(sport=1025, dport=external_port))
+        p = (
+            Ether(dst=self.pg1.local_mac, src=self.pg1.remote_mac)
+            / IP(src=self.pg1.remote_ip4, dst=self.nat_addr)
+            / TCP(sport=1025, dport=external_port)
+        )
         self.pg1.add_stream(p)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
@@ -1699,22 +1817,26 @@ class TestNAT44ED(VppTestCase):
 
         sessions = self.vapi.nat44_user_session_dump(backend, 0)
         self.assertEqual(len(sessions), 1)
-        self.assertTrue(sessions[0].flags &
-                        self.config_flags.NAT_IS_EXT_HOST_VALID)
+        self.assertTrue(sessions[0].flags & self.config_flags.NAT_IS_EXT_HOST_VALID)
         self.vapi.nat44_del_session(
             address=sessions[0].inside_ip_address,
             port=sessions[0].inside_port,
             protocol=sessions[0].protocol,
-            flags=(self.config_flags.NAT_IS_INSIDE |
-                   self.config_flags.NAT_IS_EXT_HOST_VALID),
+            flags=(
+                self.config_flags.NAT_IS_INSIDE
+                | self.config_flags.NAT_IS_EXT_HOST_VALID
+            ),
             ext_host_address=sessions[0].ext_host_address,
-            ext_host_port=sessions[0].ext_host_port)
+            ext_host_port=sessions[0].ext_host_port,
+        )
 
         pkts = []
         for port in range(1030, 1100):
-            p = (Ether(dst=self.pg1.local_mac, src=self.pg1.remote_mac) /
-                 IP(src=self.pg1.remote_ip4, dst=self.nat_addr) /
-                 TCP(sport=port, dport=external_port))
+            p = (
+                Ether(dst=self.pg1.local_mac, src=self.pg1.remote_mac)
+                / IP(src=self.pg1.remote_ip4, dst=self.nat_addr)
+                / TCP(sport=port, dport=external_port)
+            )
             pkts.append(p)
         self.pg1.add_stream(pkts)
         self.pg_enable_capture(self.pg_interfaces)
@@ -1724,31 +1846,39 @@ class TestNAT44ED(VppTestCase):
             self.assertEqual(p[IP].dst, backend)
 
     def test_multiple_vrf_1(self):
-        """ Multiple VRF - both client & service in VRF1 """
+        """Multiple VRF - both client & service in VRF1"""
 
-        external_addr = '1.2.3.4'
+        external_addr = "1.2.3.4"
         external_port = 80
         local_port = 8080
         port = 0
 
         flags = self.config_flags.NAT_IS_INSIDE
         self.vapi.nat44_interface_add_del_feature(
-            sw_if_index=self.pg5.sw_if_index,
-            is_add=1)
+            sw_if_index=self.pg5.sw_if_index, is_add=1
+        )
         self.vapi.nat44_interface_add_del_feature(
-            sw_if_index=self.pg5.sw_if_index,
-            is_add=1, flags=flags)
+            sw_if_index=self.pg5.sw_if_index, is_add=1, flags=flags
+        )
         self.vapi.nat44_interface_add_del_feature(
-            sw_if_index=self.pg6.sw_if_index,
-            is_add=1)
+            sw_if_index=self.pg6.sw_if_index, is_add=1
+        )
         flags = self.config_flags.NAT_IS_OUT2IN_ONLY
-        self.nat_add_static_mapping(self.pg5.remote_ip4, external_addr,
-                                    local_port, external_port, vrf_id=1,
-                                    proto=IP_PROTOS.tcp, flags=flags)
+        self.nat_add_static_mapping(
+            self.pg5.remote_ip4,
+            external_addr,
+            local_port,
+            external_port,
+            vrf_id=1,
+            proto=IP_PROTOS.tcp,
+            flags=flags,
+        )
 
-        p = (Ether(src=self.pg6.remote_mac, dst=self.pg6.local_mac) /
-             IP(src=self.pg6.remote_ip4, dst=external_addr) /
-             TCP(sport=12345, dport=external_port))
+        p = (
+            Ether(src=self.pg6.remote_mac, dst=self.pg6.local_mac)
+            / IP(src=self.pg6.remote_ip4, dst=external_addr)
+            / TCP(sport=12345, dport=external_port)
+        )
         self.pg6.add_stream(p)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
@@ -1764,9 +1894,11 @@ class TestNAT44ED(VppTestCase):
             self.logger.error(ppp("Unexpected or invalid packet:", p))
             raise
 
-        p = (Ether(src=self.pg5.remote_mac, dst=self.pg5.local_mac) /
-             IP(src=self.pg5.remote_ip4, dst=self.pg6.remote_ip4) /
-             TCP(sport=local_port, dport=12345))
+        p = (
+            Ether(src=self.pg5.remote_mac, dst=self.pg5.local_mac)
+            / IP(src=self.pg5.remote_ip4, dst=self.pg6.remote_ip4)
+            / TCP(sport=local_port, dport=12345)
+        )
         self.pg5.add_stream(p)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
@@ -1783,9 +1915,9 @@ class TestNAT44ED(VppTestCase):
             raise
 
     def test_multiple_vrf_2(self):
-        """ Multiple VRF - dynamic NAT from VRF1 to VRF0 (output-feature) """
+        """Multiple VRF - dynamic NAT from VRF1 to VRF0 (output-feature)"""
 
-        external_addr = '1.2.3.4'
+        external_addr = "1.2.3.4"
         external_port = 80
         local_port = 8080
         port = 0
@@ -1793,22 +1925,30 @@ class TestNAT44ED(VppTestCase):
         self.nat_add_address(self.nat_addr)
         flags = self.config_flags.NAT_IS_INSIDE
         self.vapi.nat44_ed_add_del_output_interface(
-            sw_if_index=self.pg1.sw_if_index,
-            is_add=1)
+            sw_if_index=self.pg1.sw_if_index, is_add=1
+        )
         self.vapi.nat44_interface_add_del_feature(
-            sw_if_index=self.pg5.sw_if_index,
-            is_add=1)
+            sw_if_index=self.pg5.sw_if_index, is_add=1
+        )
         self.vapi.nat44_interface_add_del_feature(
-            sw_if_index=self.pg5.sw_if_index,
-            is_add=1, flags=flags)
+            sw_if_index=self.pg5.sw_if_index, is_add=1, flags=flags
+        )
         flags = self.config_flags.NAT_IS_OUT2IN_ONLY
-        self.nat_add_static_mapping(self.pg5.remote_ip4, external_addr,
-                                    local_port, external_port, vrf_id=1,
-                                    proto=IP_PROTOS.tcp, flags=flags)
+        self.nat_add_static_mapping(
+            self.pg5.remote_ip4,
+            external_addr,
+            local_port,
+            external_port,
+            vrf_id=1,
+            proto=IP_PROTOS.tcp,
+            flags=flags,
+        )
 
-        p = (Ether(src=self.pg5.remote_mac, dst=self.pg5.local_mac) /
-             IP(src=self.pg5.remote_ip4, dst=self.pg1.remote_ip4) /
-             TCP(sport=2345, dport=22))
+        p = (
+            Ether(src=self.pg5.remote_mac, dst=self.pg5.local_mac)
+            / IP(src=self.pg5.remote_ip4, dst=self.pg1.remote_ip4)
+            / TCP(sport=2345, dport=22)
+        )
         self.pg5.add_stream(p)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
@@ -1824,9 +1964,11 @@ class TestNAT44ED(VppTestCase):
             self.logger.error(ppp("Unexpected or invalid packet:", p))
             raise
 
-        p = (Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac) /
-             IP(src=self.pg1.remote_ip4, dst=self.nat_addr) /
-             TCP(sport=22, dport=port))
+        p = (
+            Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac)
+            / IP(src=self.pg1.remote_ip4, dst=self.nat_addr)
+            / TCP(sport=22, dport=port)
+        )
         self.pg1.add_stream(p)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
@@ -1843,23 +1985,23 @@ class TestNAT44ED(VppTestCase):
             raise
 
     def test_multiple_vrf_3(self):
-        """ Multiple VRF - client in VRF1, service in VRF0 """
+        """Multiple VRF - client in VRF1, service in VRF0"""
 
-        external_addr = '1.2.3.4'
+        external_addr = "1.2.3.4"
         external_port = 80
         local_port = 8080
         port = 0
 
         flags = self.config_flags.NAT_IS_INSIDE
         self.vapi.nat44_interface_add_del_feature(
-            sw_if_index=self.pg0.sw_if_index,
-            is_add=1)
+            sw_if_index=self.pg0.sw_if_index, is_add=1
+        )
         self.vapi.nat44_interface_add_del_feature(
-            sw_if_index=self.pg0.sw_if_index,
-            is_add=1, flags=flags)
+            sw_if_index=self.pg0.sw_if_index, is_add=1, flags=flags
+        )
         self.vapi.nat44_interface_add_del_feature(
-            sw_if_index=self.pg6.sw_if_index,
-            is_add=1)
+            sw_if_index=self.pg6.sw_if_index, is_add=1
+        )
         flags = self.config_flags.NAT_IS_OUT2IN_ONLY
         self.nat_add_static_mapping(
             self.pg0.remote_ip4,
@@ -1868,13 +2010,15 @@ class TestNAT44ED(VppTestCase):
             vrf_id=0,
             external_port=external_port,
             proto=IP_PROTOS.tcp,
-            flags=flags
+            flags=flags,
         )
 
         # from client VRF1 to service VRF0
-        p = (Ether(src=self.pg6.remote_mac, dst=self.pg6.local_mac) /
-             IP(src=self.pg6.remote_ip4, dst=self.pg0.local_ip4) /
-             TCP(sport=12346, dport=external_port))
+        p = (
+            Ether(src=self.pg6.remote_mac, dst=self.pg6.local_mac)
+            / IP(src=self.pg6.remote_ip4, dst=self.pg0.local_ip4)
+            / TCP(sport=12346, dport=external_port)
+        )
         self.pg6.add_stream(p)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
@@ -1891,9 +2035,11 @@ class TestNAT44ED(VppTestCase):
             raise
 
         # from service VRF0 back to client VRF1
-        p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
-             IP(src=self.pg0.remote_ip4, dst=self.pg6.remote_ip4) /
-             TCP(sport=local_port, dport=12346))
+        p = (
+            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+            / IP(src=self.pg0.remote_ip4, dst=self.pg6.remote_ip4)
+            / TCP(sport=local_port, dport=12346)
+        )
         self.pg0.add_stream(p)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
@@ -1910,35 +2056,43 @@ class TestNAT44ED(VppTestCase):
             raise
 
     def test_multiple_vrf_4(self):
-        """ Multiple VRF - client in VRF0, service in VRF1 """
+        """Multiple VRF - client in VRF0, service in VRF1"""
 
-        external_addr = '1.2.3.4'
+        external_addr = "1.2.3.4"
         external_port = 80
         local_port = 8080
         port = 0
 
         flags = self.config_flags.NAT_IS_INSIDE
         self.vapi.nat44_interface_add_del_feature(
-            sw_if_index=self.pg0.sw_if_index,
-            is_add=1)
+            sw_if_index=self.pg0.sw_if_index, is_add=1
+        )
         self.vapi.nat44_interface_add_del_feature(
-            sw_if_index=self.pg0.sw_if_index,
-            is_add=1, flags=flags)
+            sw_if_index=self.pg0.sw_if_index, is_add=1, flags=flags
+        )
         self.vapi.nat44_interface_add_del_feature(
-            sw_if_index=self.pg5.sw_if_index,
-            is_add=1)
+            sw_if_index=self.pg5.sw_if_index, is_add=1
+        )
         self.vapi.nat44_interface_add_del_feature(
-            sw_if_index=self.pg5.sw_if_index,
-            is_add=1, flags=flags)
+            sw_if_index=self.pg5.sw_if_index, is_add=1, flags=flags
+        )
         flags = self.config_flags.NAT_IS_OUT2IN_ONLY
-        self.nat_add_static_mapping(self.pg5.remote_ip4, external_addr,
-                                    local_port, external_port, vrf_id=1,
-                                    proto=IP_PROTOS.tcp, flags=flags)
+        self.nat_add_static_mapping(
+            self.pg5.remote_ip4,
+            external_addr,
+            local_port,
+            external_port,
+            vrf_id=1,
+            proto=IP_PROTOS.tcp,
+            flags=flags,
+        )
 
         # from client VRF0 to service VRF1
-        p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
-             IP(src=self.pg0.remote_ip4, dst=external_addr) /
-             TCP(sport=12347, dport=external_port))
+        p = (
+            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+            / IP(src=self.pg0.remote_ip4, dst=external_addr)
+            / TCP(sport=12347, dport=external_port)
+        )
         self.pg0.add_stream(p)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
@@ -1955,9 +2109,11 @@ class TestNAT44ED(VppTestCase):
             raise
 
         # from service VRF1 back to client VRF0
-        p = (Ether(src=self.pg5.remote_mac, dst=self.pg5.local_mac) /
-             IP(src=self.pg5.remote_ip4, dst=self.pg0.remote_ip4) /
-             TCP(sport=local_port, dport=12347))
+        p = (
+            Ether(src=self.pg5.remote_mac, dst=self.pg5.local_mac)
+            / IP(src=self.pg5.remote_ip4, dst=self.pg0.remote_ip4)
+            / TCP(sport=local_port, dport=12347)
+        )
         self.pg5.add_stream(p)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
@@ -1974,9 +2130,9 @@ class TestNAT44ED(VppTestCase):
             raise
 
     def test_multiple_vrf_5(self):
-        """ Multiple VRF - forwarding - no translation """
+        """Multiple VRF - forwarding - no translation"""
 
-        external_addr = '1.2.3.4'
+        external_addr = "1.2.3.4"
         external_port = 80
         local_port = 8080
         port = 0
@@ -1984,24 +2140,30 @@ class TestNAT44ED(VppTestCase):
         self.vapi.nat44_forwarding_enable_disable(enable=1)
         flags = self.config_flags.NAT_IS_INSIDE
         self.vapi.nat44_interface_add_del_feature(
-            sw_if_index=self.pg0.sw_if_index,
-            is_add=1)
+            sw_if_index=self.pg0.sw_if_index, is_add=1
+        )
         self.vapi.nat44_interface_add_del_feature(
-            sw_if_index=self.pg0.sw_if_index,
-            is_add=1, flags=flags)
+            sw_if_index=self.pg0.sw_if_index, is_add=1, flags=flags
+        )
         self.vapi.nat44_interface_add_del_feature(
-            sw_if_index=self.pg5.sw_if_index,
-            is_add=1)
+            sw_if_index=self.pg5.sw_if_index, is_add=1
+        )
         self.vapi.nat44_interface_add_del_feature(
-            sw_if_index=self.pg5.sw_if_index,
-            is_add=1, flags=flags)
+            sw_if_index=self.pg5.sw_if_index, is_add=1, flags=flags
+        )
         self.vapi.nat44_interface_add_del_feature(
-            sw_if_index=self.pg6.sw_if_index,
-            is_add=1)
+            sw_if_index=self.pg6.sw_if_index, is_add=1
+        )
         flags = self.config_flags.NAT_IS_OUT2IN_ONLY
-        self.nat_add_static_mapping(self.pg5.remote_ip4, external_addr,
-                                    local_port, external_port, vrf_id=1,
-                                    proto=IP_PROTOS.tcp, flags=flags)
+        self.nat_add_static_mapping(
+            self.pg5.remote_ip4,
+            external_addr,
+            local_port,
+            external_port,
+            vrf_id=1,
+            proto=IP_PROTOS.tcp,
+            flags=flags,
+        )
         self.nat_add_static_mapping(
             self.pg0.remote_ip4,
             external_sw_if_index=self.pg0.sw_if_index,
@@ -2009,13 +2171,15 @@ class TestNAT44ED(VppTestCase):
             vrf_id=0,
             external_port=external_port,
             proto=IP_PROTOS.tcp,
-            flags=flags
+            flags=flags,
         )
 
         # from client to server (both VRF1, no translation)
-        p = (Ether(src=self.pg6.remote_mac, dst=self.pg6.local_mac) /
-             IP(src=self.pg6.remote_ip4, dst=self.pg5.remote_ip4) /
-             TCP(sport=12348, dport=local_port))
+        p = (
+            Ether(src=self.pg6.remote_mac, dst=self.pg6.local_mac)
+            / IP(src=self.pg6.remote_ip4, dst=self.pg5.remote_ip4)
+            / TCP(sport=12348, dport=local_port)
+        )
         self.pg6.add_stream(p)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
@@ -2032,9 +2196,11 @@ class TestNAT44ED(VppTestCase):
             raise
 
         # from server back to client (both VRF1, no translation)
-        p = (Ether(src=self.pg5.remote_mac, dst=self.pg5.local_mac) /
-             IP(src=self.pg5.remote_ip4, dst=self.pg6.remote_ip4) /
-             TCP(sport=local_port, dport=12348))
+        p = (
+            Ether(src=self.pg5.remote_mac, dst=self.pg5.local_mac)
+            / IP(src=self.pg5.remote_ip4, dst=self.pg6.remote_ip4)
+            / TCP(sport=local_port, dport=12348)
+        )
         self.pg5.add_stream(p)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
@@ -2051,9 +2217,11 @@ class TestNAT44ED(VppTestCase):
             raise
 
         # from client VRF1 to server VRF0 (no translation)
-        p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
-             IP(src=self.pg0.remote_ip4, dst=self.pg6.remote_ip4) /
-             TCP(sport=local_port, dport=12349))
+        p = (
+            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+            / IP(src=self.pg0.remote_ip4, dst=self.pg6.remote_ip4)
+            / TCP(sport=local_port, dport=12349)
+        )
         self.pg0.add_stream(p)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
@@ -2070,9 +2238,11 @@ class TestNAT44ED(VppTestCase):
             raise
 
         # from server VRF0 back to client VRF1 (no translation)
-        p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
-             IP(src=self.pg0.remote_ip4, dst=self.pg6.remote_ip4) /
-             TCP(sport=local_port, dport=12349))
+        p = (
+            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+            / IP(src=self.pg0.remote_ip4, dst=self.pg6.remote_ip4)
+            / TCP(sport=local_port, dport=12349)
+        )
         self.pg0.add_stream(p)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
@@ -2089,9 +2259,11 @@ class TestNAT44ED(VppTestCase):
             raise
 
         # from client VRF0 to server VRF1 (no translation)
-        p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
-             IP(src=self.pg0.remote_ip4, dst=self.pg5.remote_ip4) /
-             TCP(sport=12344, dport=local_port))
+        p = (
+            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+            / IP(src=self.pg0.remote_ip4, dst=self.pg5.remote_ip4)
+            / TCP(sport=12344, dport=local_port)
+        )
         self.pg0.add_stream(p)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
@@ -2108,9 +2280,11 @@ class TestNAT44ED(VppTestCase):
             raise
 
         # from server VRF1 back to client VRF0 (no translation)
-        p = (Ether(src=self.pg5.remote_mac, dst=self.pg5.local_mac) /
-             IP(src=self.pg5.remote_ip4, dst=self.pg0.remote_ip4) /
-             TCP(sport=local_port, dport=12344))
+        p = (
+            Ether(src=self.pg5.remote_mac, dst=self.pg5.local_mac)
+            / IP(src=self.pg5.remote_ip4, dst=self.pg0.remote_ip4)
+            / TCP(sport=local_port, dport=12344)
+        )
         self.pg5.add_stream(p)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
@@ -2127,7 +2301,7 @@ class TestNAT44ED(VppTestCase):
             raise
 
     def test_outside_address_distribution(self):
-        """ Outside address distribution based on source address """
+        """Outside address distribution based on source address"""
 
         x = 100
         nat_addresses = []
@@ -2142,7 +2316,10 @@ class TestNAT44ED(VppTestCase):
         self.vapi.nat44_add_del_address_range(
             first_ip_address=nat_addresses[0],
             last_ip_address=nat_addresses[-1],
-            vrf_id=0xFFFFFFFF, is_add=1, flags=0)
+            vrf_id=0xFFFFFFFF,
+            is_add=1,
+            flags=0,
+        )
 
         self.pg0.generate_remote_hosts(x)
 
@@ -2150,11 +2327,12 @@ class TestNAT44ED(VppTestCase):
         for i in range(x):
             info = self.create_packet_info(self.pg0, self.pg1)
             payload = self.info_to_payload(info)
-            p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
-                 IP(src=self.pg0.remote_hosts[i].ip4,
-                     dst=self.pg1.remote_ip4) /
-                 UDP(sport=7000+i, dport=8000+i) /
-                 Raw(payload))
+            p = (
+                Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac)
+                / IP(src=self.pg0.remote_hosts[i].ip4, dst=self.pg1.remote_ip4)
+                / UDP(sport=7000 + i, dport=8000 + i)
+                / Raw(payload)
+            )
             info.data = p
             pkts.append(p)
 
@@ -2172,20 +2350,23 @@ class TestNAT44ED(VppTestCase):
             packed = socket.inet_aton(p_sent[IP].src)
             numeric = struct.unpack("!L", packed)[0]
             numeric = socket.htonl(numeric)
-            a = nat_addresses[(numeric-1) % len(nat_addresses)]
+            a = nat_addresses[(numeric - 1) % len(nat_addresses)]
             self.assertEqual(
-                a, p_recvd[IP].src,
+                a,
+                p_recvd[IP].src,
                 "Invalid packet (src IP %s translated to %s, but expected %s)"
-                % (p_sent[IP].src, p_recvd[IP].src, a))
+                % (p_sent[IP].src, p_recvd[IP].src, a),
+            )
 
 
 class TestNAT44EDMW(TestNAT44ED):
-    """ NAT44ED MW Test Case """
+    """NAT44ED MW Test Case"""
+
     vpp_worker_count = 4
     max_sessions = 5000
 
     def test_dynamic(self):
-        """ NAT44ED dynamic translation test """
+        """NAT44ED dynamic translation test"""
         pkt_count = 1500
         tcp_port_offset = 20
         udp_port_offset = 20
@@ -2196,27 +2377,33 @@ class TestNAT44EDMW(TestNAT44ED):
         self.nat_add_outside_interface(self.pg1)
 
         # in2out
-        tc1 = self.statistics['/nat44-ed/in2out/slowpath/tcp']
-        uc1 = self.statistics['/nat44-ed/in2out/slowpath/udp']
-        ic1 = self.statistics['/nat44-ed/in2out/slowpath/icmp']
-        dc1 = self.statistics['/nat44-ed/in2out/slowpath/drops']
+        tc1 = self.statistics["/nat44-ed/in2out/slowpath/tcp"]
+        uc1 = self.statistics["/nat44-ed/in2out/slowpath/udp"]
+        ic1 = self.statistics["/nat44-ed/in2out/slowpath/icmp"]
+        dc1 = self.statistics["/nat44-ed/in2out/slowpath/drops"]
 
         i2o_pkts = [[] for x in range(0, self.vpp_worker_count)]
 
         for i in range(pkt_count):
-            p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
-                 IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
-                 TCP(sport=tcp_port_offset + i, dport=20))
+            p = (
+                Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac)
+                / IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4)
+                / TCP(sport=tcp_port_offset + i, dport=20)
+            )
             i2o_pkts[p[TCP].sport % self.vpp_worker_count].append(p)
 
-            p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
-                 IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
-                 UDP(sport=udp_port_offset + i, dport=20))
+            p = (
+                Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac)
+                / IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4)
+                / UDP(sport=udp_port_offset + i, dport=20)
+            )
             i2o_pkts[p[UDP].sport % self.vpp_worker_count].append(p)
 
-            p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
-                 IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
-                 ICMP(id=icmp_id_offset + i, type='echo-request'))
+            p = (
+                Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac)
+                / IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4)
+                / ICMP(id=icmp_id_offset + i, type="echo-request")
+            )
             i2o_pkts[p[ICMP].id % self.vpp_worker_count].append(p)
 
         for i in range(0, self.vpp_worker_count):
@@ -2228,26 +2415,23 @@ class TestNAT44EDMW(TestNAT44ED):
         capture = self.pg1.get_capture(pkt_count * 3, timeout=5)
 
         if_idx = self.pg0.sw_if_index
-        tc2 = self.statistics['/nat44-ed/in2out/slowpath/tcp']
-        uc2 = self.statistics['/nat44-ed/in2out/slowpath/udp']
-        ic2 = self.statistics['/nat44-ed/in2out/slowpath/icmp']
-        dc2 = self.statistics['/nat44-ed/in2out/slowpath/drops']
-
-        self.assertEqual(
-            tc2[:, if_idx].sum() - tc1[:, if_idx].sum(), pkt_count)
-        self.assertEqual(
-            uc2[:, if_idx].sum() - uc1[:, if_idx].sum(), pkt_count)
-        self.assertEqual(
-            ic2[:, if_idx].sum() - ic1[:, if_idx].sum(), pkt_count)
+        tc2 = self.statistics["/nat44-ed/in2out/slowpath/tcp"]
+        uc2 = self.statistics["/nat44-ed/in2out/slowpath/udp"]
+        ic2 = self.statistics["/nat44-ed/in2out/slowpath/icmp"]
+        dc2 = self.statistics["/nat44-ed/in2out/slowpath/drops"]
+
+        self.assertEqual(tc2[:, if_idx].sum() - tc1[:, if_idx].sum(), pkt_count)
+        self.assertEqual(uc2[:, if_idx].sum() - uc1[:, if_idx].sum(), pkt_count)
+        self.assertEqual(ic2[:, if_idx].sum() - ic1[:, if_idx].sum(), pkt_count)
         self.assertEqual(dc2[:, if_idx].sum() - dc1[:, if_idx].sum(), 0)
 
         self.logger.info(self.vapi.cli("show trace"))
 
         # out2in
-        tc1 = self.statistics['/nat44-ed/out2in/fastpath/tcp']
-        uc1 = self.statistics['/nat44-ed/out2in/fastpath/udp']
-        ic1 = self.statistics['/nat44-ed/out2in/fastpath/icmp']
-        dc1 = self.statistics['/nat44-ed/out2in/fastpath/drops']
+        tc1 = self.statistics["/nat44-ed/out2in/fastpath/tcp"]
+        uc1 = self.statistics["/nat44-ed/out2in/fastpath/udp"]
+        ic1 = self.statistics["/nat44-ed/out2in/fastpath/icmp"]
+        dc1 = self.statistics["/nat44-ed/out2in/fastpath/drops"]
 
         recvd_tcp_ports = set()
         recvd_udp_ports = set()
@@ -2267,19 +2451,25 @@ class TestNAT44EDMW(TestNAT44ED):
 
         o2i_pkts = [[] for x in range(0, self.vpp_worker_count)]
         for i in range(pkt_count):
-            p = (Ether(dst=self.pg1.local_mac, src=self.pg1.remote_mac) /
-                 IP(src=self.pg1.remote_ip4, dst=self.nat_addr) /
-                 TCP(dport=choice(recvd_tcp_ports), sport=20))
+            p = (
+                Ether(dst=self.pg1.local_mac, src=self.pg1.remote_mac)
+                / IP(src=self.pg1.remote_ip4, dst=self.nat_addr)
+                / TCP(dport=choice(recvd_tcp_ports), sport=20)
+            )
             o2i_pkts[p[TCP].dport % self.vpp_worker_count].append(p)
 
-            p = (Ether(dst=self.pg1.local_mac, src=self.pg1.remote_mac) /
-                 IP(src=self.pg1.remote_ip4, dst=self.nat_addr) /
-                 UDP(dport=choice(recvd_udp_ports), sport=20))
+            p = (
+                Ether(dst=self.pg1.local_mac, src=self.pg1.remote_mac)
+                / IP(src=self.pg1.remote_ip4, dst=self.nat_addr)
+                / UDP(dport=choice(recvd_udp_ports), sport=20)
+            )
             o2i_pkts[p[UDP].dport % self.vpp_worker_count].append(p)
 
-            p = (Ether(dst=self.pg1.local_mac, src=self.pg1.remote_mac) /
-                 IP(src=self.pg1.remote_ip4, dst=self.nat_addr) /
-                 ICMP(id=choice(recvd_icmp_ids), type='echo-reply'))
+            p = (
+                Ether(dst=self.pg1.local_mac, src=self.pg1.remote_mac)
+                / IP(src=self.pg1.remote_ip4, dst=self.nat_addr)
+                / ICMP(id=choice(recvd_icmp_ids), type="echo-reply")
+            )
             o2i_pkts[p[ICMP].id % self.vpp_worker_count].append(p)
 
         for i in range(0, self.vpp_worker_count):
@@ -2295,41 +2485,50 @@ class TestNAT44EDMW(TestNAT44ED):
                 self.assertEqual(packet[IP].dst, self.pg0.remote_ip4)
                 if packet.haslayer(TCP):
                     self.assert_in_range(
-                        packet[TCP].dport, tcp_port_offset,
-                        tcp_port_offset + pkt_count, "dst TCP port")
+                        packet[TCP].dport,
+                        tcp_port_offset,
+                        tcp_port_offset + pkt_count,
+                        "dst TCP port",
+                    )
                 elif packet.haslayer(UDP):
                     self.assert_in_range(
-                        packet[UDP].dport, udp_port_offset,
-                        udp_port_offset + pkt_count, "dst UDP port")
+                        packet[UDP].dport,
+                        udp_port_offset,
+                        udp_port_offset + pkt_count,
+                        "dst UDP port",
+                    )
                 else:
                     self.assert_in_range(
-                        packet[ICMP].id, icmp_id_offset,
-                        icmp_id_offset + pkt_count, "ICMP id")
+                        packet[ICMP].id,
+                        icmp_id_offset,
+                        icmp_id_offset + pkt_count,
+                        "ICMP id",
+                    )
             except:
-                self.logger.error(ppp("Unexpected or invalid packet "
-                                      "(inside network):", packet))
+                self.logger.error(
+                    ppp("Unexpected or invalid packet (inside network):", packet)
+                )
                 raise
 
         if_idx = self.pg1.sw_if_index
-        tc2 = self.statistics['/nat44-ed/out2in/fastpath/tcp']
-        uc2 = self.statistics['/nat44-ed/out2in/fastpath/udp']
-        ic2 = self.statistics['/nat44-ed/out2in/fastpath/icmp']
-        dc2 = self.statistics['/nat44-ed/out2in/fastpath/drops']
-
-        self.assertEqual(
-            tc2[:, if_idx].sum() - tc1[:, if_idx].sum(), pkt_count)
-        self.assertEqual(
-            uc2[:, if_idx].sum() - uc1[:, if_idx].sum(), pkt_count)
-        self.assertEqual(
-            ic2[:, if_idx].sum() - ic1[:, if_idx].sum(), pkt_count)
+        tc2 = self.statistics["/nat44-ed/out2in/fastpath/tcp"]
+        uc2 = self.statistics["/nat44-ed/out2in/fastpath/udp"]
+        ic2 = self.statistics["/nat44-ed/out2in/fastpath/icmp"]
+        dc2 = self.statistics["/nat44-ed/out2in/fastpath/drops"]
+
+        self.assertEqual(tc2[:, if_idx].sum() - tc1[:, if_idx].sum(), pkt_count)
+        self.assertEqual(uc2[:, if_idx].sum() - uc1[:, if_idx].sum(), pkt_count)
+        self.assertEqual(ic2[:, if_idx].sum() - ic1[:, if_idx].sum(), pkt_count)
         self.assertEqual(dc2[:, if_idx].sum() - dc1[:, if_idx].sum(), 0)
 
-        sc = self.statistics['/nat44-ed/total-sessions']
-        self.assertEqual(sc[:, 0].sum(), len(recvd_tcp_ports) +
-                         len(recvd_udp_ports) + len(recvd_icmp_ids))
+        sc = self.statistics["/nat44-ed/total-sessions"]
+        self.assertEqual(
+            sc[:, 0].sum(),
+            len(recvd_tcp_ports) + len(recvd_udp_ports) + len(recvd_icmp_ids),
+        )
 
     def test_frag_in_order(self):
-        """ NAT44ED translate fragments arriving in order """
+        """NAT44ED translate fragments arriving in order"""
 
         self.nat_add_address(self.nat_addr)
         self.nat_add_inside_interface(self.pg0)
@@ -2340,7 +2539,7 @@ class TestNAT44EDMW(TestNAT44ED):
         self.frag_in_order(proto=IP_PROTOS.icmp, ignore_port=True)
 
     def test_frag_in_order_do_not_translate(self):
-        """ NAT44ED don't translate fragments arriving in order """
+        """NAT44ED don't translate fragments arriving in order"""
 
         self.nat_add_address(self.nat_addr)
         self.nat_add_inside_interface(self.pg0)
@@ -2350,7 +2549,7 @@ class TestNAT44EDMW(TestNAT44ED):
         self.frag_in_order(proto=IP_PROTOS.tcp, dont_translate=True)
 
     def test_frag_out_of_order(self):
-        """ NAT44ED translate fragments arriving out of order """
+        """NAT44ED translate fragments arriving out of order"""
 
         self.nat_add_address(self.nat_addr)
         self.nat_add_inside_interface(self.pg0)
@@ -2361,7 +2560,7 @@ class TestNAT44EDMW(TestNAT44ED):
         self.frag_out_of_order(proto=IP_PROTOS.icmp, ignore_port=True)
 
     def test_frag_in_order_in_plus_out(self):
-        """ NAT44ED in+out interface fragments in order """
+        """NAT44ED in+out interface fragments in order"""
 
         in_port = self.random_port()
         out_port = self.random_port()
@@ -2373,39 +2572,29 @@ class TestNAT44EDMW(TestNAT44ED):
         self.nat_add_outside_interface(self.pg1)
 
         # add static mappings for server
-        self.nat_add_static_mapping(self.server_addr,
-                                    self.nat_addr,
-                                    in_port,
-                                    out_port,
-                                    proto=IP_PROTOS.tcp)
-        self.nat_add_static_mapping(self.server_addr,
-                                    self.nat_addr,
-                                    in_port,
-                                    out_port,
-                                    proto=IP_PROTOS.udp)
-        self.nat_add_static_mapping(self.server_addr,
-                                    self.nat_addr,
-                                    proto=IP_PROTOS.icmp)
+        self.nat_add_static_mapping(
+            self.server_addr, self.nat_addr, in_port, out_port, proto=IP_PROTOS.tcp
+        )
+        self.nat_add_static_mapping(
+            self.server_addr, self.nat_addr, in_port, out_port, proto=IP_PROTOS.udp
+        )
+        self.nat_add_static_mapping(
+            self.server_addr, self.nat_addr, proto=IP_PROTOS.icmp
+        )
 
         # run tests for each protocol
-        self.frag_in_order_in_plus_out(self.server_addr,
-                                       self.nat_addr,
-                                       in_port,
-                                       out_port,
-                                       IP_PROTOS.tcp)
-        self.frag_in_order_in_plus_out(self.server_addr,
-                                       self.nat_addr,
-                                       in_port,
-                                       out_port,
-                                       IP_PROTOS.udp)
-        self.frag_in_order_in_plus_out(self.server_addr,
-                                       self.nat_addr,
-                                       in_port,
-                                       out_port,
-                                       IP_PROTOS.icmp)
+        self.frag_in_order_in_plus_out(
+            self.server_addr, self.nat_addr, in_port, out_port, IP_PROTOS.tcp
+        )
+        self.frag_in_order_in_plus_out(
+            self.server_addr, self.nat_addr, in_port, out_port, IP_PROTOS.udp
+        )
+        self.frag_in_order_in_plus_out(
+            self.server_addr, self.nat_addr, in_port, out_port, IP_PROTOS.icmp
+        )
 
     def test_frag_out_of_order_in_plus_out(self):
-        """ NAT44ED in+out interface fragments out of order """
+        """NAT44ED in+out interface fragments out of order"""
 
         in_port = self.random_port()
         out_port = self.random_port()
@@ -2417,39 +2606,29 @@ class TestNAT44EDMW(TestNAT44ED):
         self.nat_add_outside_interface(self.pg1)
 
         # add static mappings for server
-        self.nat_add_static_mapping(self.server_addr,
-                                    self.nat_addr,
-                                    in_port,
-                                    out_port,
-                                    proto=IP_PROTOS.tcp)
-        self.nat_add_static_mapping(self.server_addr,
-                                    self.nat_addr,
-                                    in_port,
-                                    out_port,
-                                    proto=IP_PROTOS.udp)
-        self.nat_add_static_mapping(self.server_addr,
-                                    self.nat_addr,
-                                    proto=IP_PROTOS.icmp)
+        self.nat_add_static_mapping(
+            self.server_addr, self.nat_addr, in_port, out_port, proto=IP_PROTOS.tcp
+        )
+        self.nat_add_static_mapping(
+            self.server_addr, self.nat_addr, in_port, out_port, proto=IP_PROTOS.udp
+        )
+        self.nat_add_static_mapping(
+            self.server_addr, self.nat_addr, proto=IP_PROTOS.icmp
+        )
 
         # run tests for each protocol
-        self.frag_out_of_order_in_plus_out(self.server_addr,
-                                           self.nat_addr,
-                                           in_port,
-                                           out_port,
-                                           IP_PROTOS.tcp)
-        self.frag_out_of_order_in_plus_out(self.server_addr,
-                                           self.nat_addr,
-                                           in_port,
-                                           out_port,
-                                           IP_PROTOS.udp)
-        self.frag_out_of_order_in_plus_out(self.server_addr,
-                                           self.nat_addr,
-                                           in_port,
-                                           out_port,
-                                           IP_PROTOS.icmp)
+        self.frag_out_of_order_in_plus_out(
+            self.server_addr, self.nat_addr, in_port, out_port, IP_PROTOS.tcp
+        )
+        self.frag_out_of_order_in_plus_out(
+            self.server_addr, self.nat_addr, in_port, out_port, IP_PROTOS.udp
+        )
+        self.frag_out_of_order_in_plus_out(
+            self.server_addr, self.nat_addr, in_port, out_port, IP_PROTOS.icmp
+        )
 
     def test_reass_hairpinning(self):
-        """ NAT44ED fragments hairpinning """
+        """NAT44ED fragments hairpinning"""
 
         server_addr = self.pg0.remote_hosts[1].ip4
 
@@ -2462,26 +2641,49 @@ class TestNAT44EDMW(TestNAT44ED):
         self.nat_add_outside_interface(self.pg1)
 
         # add static mapping for server
-        self.nat_add_static_mapping(server_addr, self.nat_addr,
-                                    server_in_port, server_out_port,
-                                    proto=IP_PROTOS.tcp)
-        self.nat_add_static_mapping(server_addr, self.nat_addr,
-                                    server_in_port, server_out_port,
-                                    proto=IP_PROTOS.udp)
+        self.nat_add_static_mapping(
+            server_addr,
+            self.nat_addr,
+            server_in_port,
+            server_out_port,
+            proto=IP_PROTOS.tcp,
+        )
+        self.nat_add_static_mapping(
+            server_addr,
+            self.nat_addr,
+            server_in_port,
+            server_out_port,
+            proto=IP_PROTOS.udp,
+        )
         self.nat_add_static_mapping(server_addr, self.nat_addr)
 
-        self.reass_hairpinning(server_addr, server_in_port, server_out_port,
-                               host_in_port, proto=IP_PROTOS.tcp,
-                               ignore_port=True)
-        self.reass_hairpinning(server_addr, server_in_port, server_out_port,
-                               host_in_port, proto=IP_PROTOS.udp,
-                               ignore_port=True)
-        self.reass_hairpinning(server_addr, server_in_port, server_out_port,
-                               host_in_port, proto=IP_PROTOS.icmp,
-                               ignore_port=True)
+        self.reass_hairpinning(
+            server_addr,
+            server_in_port,
+            server_out_port,
+            host_in_port,
+            proto=IP_PROTOS.tcp,
+            ignore_port=True,
+        )
+        self.reass_hairpinning(
+            server_addr,
+            server_in_port,
+            server_out_port,
+            host_in_port,
+            proto=IP_PROTOS.udp,
+            ignore_port=True,
+        )
+        self.reass_hairpinning(
+            server_addr,
+            server_in_port,
+            server_out_port,
+            host_in_port,
+            proto=IP_PROTOS.icmp,
+            ignore_port=True,
+        )
 
     def test_session_limit_per_vrf(self):
-        """ NAT44ED per vrf session limit """
+        """NAT44ED per vrf session limit"""
 
         inside = self.pg0
         inside_vrf10 = self.pg2
@@ -2520,27 +2722,29 @@ class TestNAT44EDMW(TestNAT44ED):
         capture = outside.get_capture(len(stream))
 
     def test_show_max_translations(self):
-        """ NAT44ED API test - max translations per thread """
+        """NAT44ED API test - max translations per thread"""
         config = self.vapi.nat44_show_running_config()
-        self.assertEqual(self.max_sessions,
-                         config.sessions)
+        self.assertEqual(self.max_sessions, config.sessions)
 
     def test_lru_cleanup(self):
-        """ NAT44ED LRU cleanup algorithm """
+        """NAT44ED LRU cleanup algorithm"""
 
         self.nat_add_address(self.nat_addr)
         self.nat_add_inside_interface(self.pg0)
         self.nat_add_outside_interface(self.pg1)
 
         self.vapi.nat_set_timeouts(
-            udp=1, tcp_established=7440, tcp_transitory=30, icmp=1)
+            udp=1, tcp_established=7440, tcp_transitory=30, icmp=1
+        )
 
         tcp_port_out = self.init_tcp_session(self.pg0, self.pg1, 2000, 80)
         pkts = []
         for i in range(0, self.max_sessions - 1):
-            p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
-                 IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4, ttl=64) /
-                 UDP(sport=7000+i, dport=80))
+            p = (
+                Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac)
+                / IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4, ttl=64)
+                / UDP(sport=7000 + i, dport=80)
+            )
             pkts.append(p)
 
         self.pg0.add_stream(pkts)
@@ -2551,9 +2755,11 @@ class TestNAT44EDMW(TestNAT44ED):
 
         pkts = []
         for i in range(0, self.max_sessions - 1):
-            p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
-                 IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4, ttl=64) /
-                 ICMP(id=8000+i, type='echo-request'))
+            p = (
+                Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac)
+                / IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4, ttl=64)
+                / ICMP(id=8000 + i, type="echo-request")
+            )
             pkts.append(p)
 
         self.pg0.add_stream(pkts)
@@ -2562,79 +2768,89 @@ class TestNAT44EDMW(TestNAT44ED):
         self.pg1.get_capture(len(pkts))
 
     def test_session_rst_timeout(self):
-        """ NAT44ED session RST timeouts """
+        """NAT44ED session RST timeouts"""
 
         self.nat_add_address(self.nat_addr)
         self.nat_add_inside_interface(self.pg0)
         self.nat_add_outside_interface(self.pg1)
 
-        self.vapi.nat_set_timeouts(udp=300, tcp_established=7440,
-                                   tcp_transitory=5, icmp=60)
+        self.vapi.nat_set_timeouts(
+            udp=300, tcp_established=7440, tcp_transitory=5, icmp=60
+        )
 
-        self.init_tcp_session(self.pg0, self.pg1, self.tcp_port_in,
-                              self.tcp_external_port)
-        p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
-             IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
-             TCP(sport=self.tcp_port_in, dport=self.tcp_external_port,
-                 flags="R"))
+        self.init_tcp_session(
+            self.pg0, self.pg1, self.tcp_port_in, self.tcp_external_port
+        )
+        p = (
+            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+            / IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4)
+            / TCP(sport=self.tcp_port_in, dport=self.tcp_external_port, flags="R")
+        )
         self.send_and_expect(self.pg0, p, self.pg1)
 
         self.virtual_sleep(6)
 
         # The session is already closed
-        p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
-             IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
-             TCP(sport=self.tcp_port_in, dport=self.tcp_external_port,
-                 flags="P"))
+        p = (
+            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+            / IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4)
+            / TCP(sport=self.tcp_port_in, dport=self.tcp_external_port, flags="P")
+        )
         self.send_and_assert_no_replies(self.pg0, p, self.pg1)
 
         # The session can be re-opened
-        p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
-             IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
-             TCP(sport=self.tcp_port_in, dport=self.tcp_external_port,
-                 flags="S"))
+        p = (
+            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+            / IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4)
+            / TCP(sport=self.tcp_port_in, dport=self.tcp_external_port, flags="S")
+        )
         self.send_and_expect(self.pg0, p, self.pg1)
 
     def test_session_rst_established_timeout(self):
-        """ NAT44ED session RST timeouts """
+        """NAT44ED session RST timeouts"""
 
         self.nat_add_address(self.nat_addr)
         self.nat_add_inside_interface(self.pg0)
         self.nat_add_outside_interface(self.pg1)
 
-        self.vapi.nat_set_timeouts(udp=300, tcp_established=7440,
-                                   tcp_transitory=5, icmp=60)
+        self.vapi.nat_set_timeouts(
+            udp=300, tcp_established=7440, tcp_transitory=5, icmp=60
+        )
 
-        self.init_tcp_session(self.pg0, self.pg1, self.tcp_port_in,
-                              self.tcp_external_port)
+        self.init_tcp_session(
+            self.pg0, self.pg1, self.tcp_port_in, self.tcp_external_port
+        )
 
         # Wait at least the transitory time, the session is in established
         # state anyway. RST followed by a data packet should move it to
         # transitory state.
         self.virtual_sleep(6)
-        p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
-             IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
-             TCP(sport=self.tcp_port_in, dport=self.tcp_external_port,
-                 flags="R"))
+        p = (
+            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+            / IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4)
+            / TCP(sport=self.tcp_port_in, dport=self.tcp_external_port, flags="R")
+        )
         self.send_and_expect(self.pg0, p, self.pg1)
 
-        p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
-             IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
-             TCP(sport=self.tcp_port_in, dport=self.tcp_external_port,
-                 flags="P"))
+        p = (
+            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+            / IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4)
+            / TCP(sport=self.tcp_port_in, dport=self.tcp_external_port, flags="P")
+        )
         self.send_and_expect(self.pg0, p, self.pg1)
 
         # State is transitory, session should be closed after 6 seconds
         self.virtual_sleep(6)
 
-        p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
-             IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
-             TCP(sport=self.tcp_port_in, dport=self.tcp_external_port,
-                 flags="P"))
+        p = (
+            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+            / IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4)
+            / TCP(sport=self.tcp_port_in, dport=self.tcp_external_port, flags="P")
+        )
         self.send_and_assert_no_replies(self.pg0, p, self.pg1)
 
     def test_dynamic_out_of_ports(self):
-        """ NAT44ED dynamic translation test: out of ports """
+        """NAT44ED dynamic translation test: out of ports"""
 
         self.nat_add_inside_interface(self.pg0)
         self.nat_add_outside_interface(self.pg1)
@@ -2643,60 +2859,71 @@ class TestNAT44EDMW(TestNAT44ED):
         pkts = self.create_stream_in(self.pg0, self.pg1)
 
         self.send_and_assert_no_replies(
-            self.pg0, pkts, msg="i2o pkts",
-            stats_diff=self.no_diff | {
+            self.pg0,
+            pkts,
+            msg="i2o pkts",
+            stats_diff=self.no_diff
+            | {
                 "err": {
-                    '/err/nat44-ed-in2out-slowpath/out of ports': len(pkts),
+                    "/err/nat44-ed-in2out-slowpath/out of ports": len(pkts),
                 },
                 self.pg0.sw_if_index: {
-                    '/nat44-ed/in2out/slowpath/drops': len(pkts),
+                    "/nat44-ed/in2out/slowpath/drops": len(pkts),
                 },
-            }
+            },
         )
 
         # in2out after NAT addresses added
         self.nat_add_address(self.nat_addr)
 
-        tcpn, udpn, icmpn = (sum(x) for x in
-                             zip(*((TCP in p, UDP in p, ICMP in p)
-                                 for p in pkts)))
+        tcpn, udpn, icmpn = (
+            sum(x) for x in zip(*((TCP in p, UDP in p, ICMP in p) for p in pkts))
+        )
 
         self.send_and_expect(
-            self.pg0, pkts, self.pg1, msg="i2o pkts",
-            stats_diff=self.no_diff | {
+            self.pg0,
+            pkts,
+            self.pg1,
+            msg="i2o pkts",
+            stats_diff=self.no_diff
+            | {
                 "err": {
-                    '/err/nat44-ed-in2out-slowpath/out of ports': 0,
+                    "/err/nat44-ed-in2out-slowpath/out of ports": 0,
                 },
                 self.pg0.sw_if_index: {
-                    '/nat44-ed/in2out/slowpath/drops': 0,
-                    '/nat44-ed/in2out/slowpath/tcp': tcpn,
-                    '/nat44-ed/in2out/slowpath/udp': udpn,
-                    '/nat44-ed/in2out/slowpath/icmp': icmpn,
+                    "/nat44-ed/in2out/slowpath/drops": 0,
+                    "/nat44-ed/in2out/slowpath/tcp": tcpn,
+                    "/nat44-ed/in2out/slowpath/udp": udpn,
+                    "/nat44-ed/in2out/slowpath/icmp": icmpn,
                 },
-            }
+            },
         )
 
     def test_unknown_proto(self):
-        """ NAT44ED translate packet with unknown protocol """
+        """NAT44ED translate packet with unknown protocol"""
 
         self.nat_add_address(self.nat_addr)
         self.nat_add_inside_interface(self.pg0)
         self.nat_add_outside_interface(self.pg1)
 
         # in2out
-        p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
-             IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
-             TCP(sport=self.tcp_port_in, dport=20))
+        p = (
+            Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac)
+            / IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4)
+            / TCP(sport=self.tcp_port_in, dport=20)
+        )
         self.pg0.add_stream(p)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
         p = self.pg1.get_capture(1)
 
-        p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
-             IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
-             GRE() /
-             IP(src=self.pg2.remote_ip4, dst=self.pg2.remote_ip4) /
-             TCP(sport=1234, dport=1234))
+        p = (
+            Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac)
+            / IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4)
+            / GRE()
+            / IP(src=self.pg2.remote_ip4, dst=self.pg2.remote_ip4)
+            / TCP(sport=1234, dport=1234)
+        )
         self.pg0.add_stream(p)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
@@ -2712,11 +2939,13 @@ class TestNAT44EDMW(TestNAT44ED):
             raise
 
         # out2in
-        p = (Ether(dst=self.pg1.local_mac, src=self.pg1.remote_mac) /
-             IP(src=self.pg1.remote_ip4, dst=self.nat_addr) /
-             GRE() /
-             IP(src=self.pg2.remote_ip4, dst=self.pg2.remote_ip4) /
-             TCP(sport=1234, dport=1234))
+        p = (
+            Ether(dst=self.pg1.local_mac, src=self.pg1.remote_mac)
+            / IP(src=self.pg1.remote_ip4, dst=self.nat_addr)
+            / GRE()
+            / IP(src=self.pg2.remote_ip4, dst=self.pg2.remote_ip4)
+            / TCP(sport=1234, dport=1234)
+        )
         self.pg1.add_stream(p)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
@@ -2732,7 +2961,7 @@ class TestNAT44EDMW(TestNAT44ED):
             raise
 
     def test_hairpinning_unknown_proto(self):
-        """ NAT44ED translate packet with unknown protocol - hairpinning """
+        """NAT44ED translate packet with unknown protocol - hairpinning"""
         host = self.pg0.remote_hosts[0]
         server = self.pg0.remote_hosts[1]
         host_in_port = 1234
@@ -2747,19 +2976,23 @@ class TestNAT44EDMW(TestNAT44ED):
         self.nat_add_static_mapping(server.ip4, server_nat_ip)
 
         # host to server
-        p = (Ether(src=host.mac, dst=self.pg0.local_mac) /
-             IP(src=host.ip4, dst=server_nat_ip) /
-             TCP(sport=host_in_port, dport=server_out_port))
+        p = (
+            Ether(src=host.mac, dst=self.pg0.local_mac)
+            / IP(src=host.ip4, dst=server_nat_ip)
+            / TCP(sport=host_in_port, dport=server_out_port)
+        )
         self.pg0.add_stream(p)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
         self.pg0.get_capture(1)
 
-        p = (Ether(dst=self.pg0.local_mac, src=host.mac) /
-             IP(src=host.ip4, dst=server_nat_ip) /
-             GRE() /
-             IP(src=self.pg2.remote_ip4, dst=self.pg2.remote_ip4) /
-             TCP(sport=1234, dport=1234))
+        p = (
+            Ether(dst=self.pg0.local_mac, src=host.mac)
+            / IP(src=host.ip4, dst=server_nat_ip)
+            / GRE()
+            / IP(src=self.pg2.remote_ip4, dst=self.pg2.remote_ip4)
+            / TCP(sport=1234, dport=1234)
+        )
         self.pg0.add_stream(p)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
@@ -2775,11 +3008,13 @@ class TestNAT44EDMW(TestNAT44ED):
             raise
 
         # server to host
-        p = (Ether(dst=self.pg0.local_mac, src=server.mac) /
-             IP(src=server.ip4, dst=self.nat_addr) /
-             GRE() /
-             IP(src=self.pg2.remote_ip4, dst=self.pg2.remote_ip4) /
-             TCP(sport=1234, dport=1234))
+        p = (
+            Ether(dst=self.pg0.local_mac, src=server.mac)
+            / IP(src=server.ip4, dst=self.nat_addr)
+            / GRE()
+            / IP(src=self.pg2.remote_ip4, dst=self.pg2.remote_ip4)
+            / TCP(sport=1234, dport=1234)
+        )
         self.pg0.add_stream(p)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
@@ -2795,8 +3030,8 @@ class TestNAT44EDMW(TestNAT44ED):
             raise
 
     def test_output_feature_and_service(self):
-        """ NAT44ED interface output feature and services """
-        external_addr = '1.2.3.4'
+        """NAT44ED interface output feature and services"""
+        external_addr = "1.2.3.4"
         external_port = 80
         local_port = 8080
 
@@ -2804,22 +3039,33 @@ class TestNAT44EDMW(TestNAT44ED):
         self.nat_add_address(self.nat_addr)
         flags = self.config_flags.NAT_IS_ADDR_ONLY
         self.vapi.nat44_add_del_identity_mapping(
-            ip_address=self.pg1.remote_ip4, sw_if_index=0xFFFFFFFF,
-            flags=flags, is_add=1)
+            ip_address=self.pg1.remote_ip4,
+            sw_if_index=0xFFFFFFFF,
+            flags=flags,
+            is_add=1,
+        )
         flags = self.config_flags.NAT_IS_OUT2IN_ONLY
-        self.nat_add_static_mapping(self.pg0.remote_ip4, external_addr,
-                                    local_port, external_port,
-                                    proto=IP_PROTOS.tcp, flags=flags)
+        self.nat_add_static_mapping(
+            self.pg0.remote_ip4,
+            external_addr,
+            local_port,
+            external_port,
+            proto=IP_PROTOS.tcp,
+            flags=flags,
+        )
 
         self.nat_add_inside_interface(self.pg0)
         self.nat_add_outside_interface(self.pg0)
         self.vapi.nat44_ed_add_del_output_interface(
-            sw_if_index=self.pg1.sw_if_index, is_add=1)
+            sw_if_index=self.pg1.sw_if_index, is_add=1
+        )
 
         # from client to service
-        p = (Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac) /
-             IP(src=self.pg1.remote_ip4, dst=external_addr) /
-             TCP(sport=12345, dport=external_port))
+        p = (
+            Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac)
+            / IP(src=self.pg1.remote_ip4, dst=external_addr)
+            / TCP(sport=12345, dport=external_port)
+        )
         self.pg1.add_stream(p)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
@@ -2836,9 +3082,11 @@ class TestNAT44EDMW(TestNAT44ED):
             raise
 
         # from service back to client
-        p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
-             IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
-             TCP(sport=local_port, dport=12345))
+        p = (
+            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+            / IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4)
+            / TCP(sport=local_port, dport=12345)
+        )
         self.pg0.add_stream(p)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
@@ -2877,26 +3125,34 @@ class TestNAT44EDMW(TestNAT44ED):
         self.verify_capture_in(capture, self.pg0)
 
     def test_output_feature_and_service3(self):
-        """ NAT44ED interface output feature and DST NAT """
-        external_addr = '1.2.3.4'
+        """NAT44ED interface output feature and DST NAT"""
+        external_addr = "1.2.3.4"
         external_port = 80
         local_port = 8080
 
         self.vapi.nat44_forwarding_enable_disable(enable=1)
         self.nat_add_address(self.nat_addr)
         flags = self.config_flags.NAT_IS_OUT2IN_ONLY
-        self.nat_add_static_mapping(self.pg1.remote_ip4, external_addr,
-                                    local_port, external_port,
-                                    proto=IP_PROTOS.tcp, flags=flags)
+        self.nat_add_static_mapping(
+            self.pg1.remote_ip4,
+            external_addr,
+            local_port,
+            external_port,
+            proto=IP_PROTOS.tcp,
+            flags=flags,
+        )
 
         self.nat_add_inside_interface(self.pg0)
         self.nat_add_outside_interface(self.pg0)
         self.vapi.nat44_ed_add_del_output_interface(
-            sw_if_index=self.pg1.sw_if_index, is_add=1)
+            sw_if_index=self.pg1.sw_if_index, is_add=1
+        )
 
-        p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
-             IP(src=self.pg0.remote_ip4, dst=external_addr) /
-             TCP(sport=12345, dport=external_port))
+        p = (
+            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+            / IP(src=self.pg0.remote_ip4, dst=external_addr)
+            / TCP(sport=12345, dport=external_port)
+        )
         self.pg0.add_stream(p)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
@@ -2914,9 +3170,11 @@ class TestNAT44EDMW(TestNAT44ED):
             self.logger.error(ppp("Unexpected or invalid packet:", p))
             raise
 
-        p = (Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac) /
-             IP(src=self.pg1.remote_ip4, dst=self.pg0.remote_ip4) /
-             TCP(sport=local_port, dport=12345))
+        p = (
+            Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac)
+            / IP(src=self.pg1.remote_ip4, dst=self.pg0.remote_ip4)
+            / TCP(sport=local_port, dport=12345)
+        )
         self.pg1.add_stream(p)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
@@ -2935,17 +3193,15 @@ class TestNAT44EDMW(TestNAT44ED):
             raise
 
     def test_self_twice_nat_lb_negative(self):
-        """ NAT44ED Self Twice NAT local service load balancing (negative test)
-        """
-        self.twice_nat_common(lb=True, self_twice_nat=True, same_pg=True,
-                              client_id=2)
+        """NAT44ED Self Twice NAT local service load balancing (negative test)"""
+        self.twice_nat_common(lb=True, self_twice_nat=True, same_pg=True, client_id=2)
 
     def test_self_twice_nat_negative(self):
-        """ NAT44ED Self Twice NAT (negative test) """
+        """NAT44ED Self Twice NAT (negative test)"""
         self.twice_nat_common(self_twice_nat=True)
 
     def test_static_lb_multi_clients(self):
-        """ NAT44ED local service load balancing - multiple clients"""
+        """NAT44ED local service load balancing - multiple clients"""
 
         external_addr = self.nat_addr
         external_port = 80
@@ -2954,39 +3210,39 @@ class TestNAT44EDMW(TestNAT44ED):
         server2 = self.pg0.remote_hosts[1]
         server3 = self.pg0.remote_hosts[2]
 
-        locals = [{'addr': server1.ip4,
-                   'port': local_port,
-                   'probability': 90,
-                   'vrf_id': 0},
-                  {'addr': server2.ip4,
-                   'port': local_port,
-                   'probability': 10,
-                   'vrf_id': 0}]
+        locals = [
+            {"addr": server1.ip4, "port": local_port, "probability": 90, "vrf_id": 0},
+            {"addr": server2.ip4, "port": local_port, "probability": 10, "vrf_id": 0},
+        ]
 
         flags = self.config_flags.NAT_IS_INSIDE
         self.vapi.nat44_interface_add_del_feature(
-            sw_if_index=self.pg0.sw_if_index,
-            flags=flags, is_add=1)
+            sw_if_index=self.pg0.sw_if_index, flags=flags, is_add=1
+        )
         self.vapi.nat44_interface_add_del_feature(
-            sw_if_index=self.pg1.sw_if_index,
-            is_add=1)
+            sw_if_index=self.pg1.sw_if_index, is_add=1
+        )
 
         self.nat_add_address(self.nat_addr)
-        self.vapi.nat44_add_del_lb_static_mapping(is_add=1,
-                                                  external_addr=external_addr,
-                                                  external_port=external_port,
-                                                  protocol=IP_PROTOS.tcp,
-                                                  local_num=len(locals),
-                                                  locals=locals)
+        self.vapi.nat44_add_del_lb_static_mapping(
+            is_add=1,
+            external_addr=external_addr,
+            external_port=external_port,
+            protocol=IP_PROTOS.tcp,
+            local_num=len(locals),
+            locals=locals,
+        )
 
         server1_n = 0
         server2_n = 0
         clients = ip4_range(self.pg1.remote_ip4, 10, 50)
         pkts = []
         for client in clients:
-            p = (Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac) /
-                 IP(src=client, dst=self.nat_addr) /
-                 TCP(sport=12345, dport=external_port))
+            p = (
+                Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac)
+                / IP(src=client, dst=self.nat_addr)
+                / TCP(sport=12345, dport=external_port)
+            )
             pkts.append(p)
         self.pg1.add_stream(pkts)
         self.pg_enable_capture(self.pg_interfaces)
@@ -3000,10 +3256,10 @@ class TestNAT44EDMW(TestNAT44ED):
         self.assertGreaterEqual(server1_n, server2_n)
 
         local = {
-            'addr': server3.ip4,
-            'port': local_port,
-            'probability': 20,
-            'vrf_id': 0
+            "addr": server3.ip4,
+            "port": local_port,
+            "probability": 20,
+            "vrf_id": 0,
         }
 
         # add new back-end
@@ -3012,16 +3268,19 @@ class TestNAT44EDMW(TestNAT44ED):
             external_addr=external_addr,
             external_port=external_port,
             local=local,
-            protocol=IP_PROTOS.tcp)
+            protocol=IP_PROTOS.tcp,
+        )
         server1_n = 0
         server2_n = 0
         server3_n = 0
         clients = ip4_range(self.pg1.remote_ip4, 60, 110)
         pkts = []
         for client in clients:
-            p = (Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac) /
-                 IP(src=client, dst=self.nat_addr) /
-                 TCP(sport=12346, dport=external_port))
+            p = (
+                Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac)
+                / IP(src=client, dst=self.nat_addr)
+                / TCP(sport=12346, dport=external_port)
+            )
             pkts.append(p)
         self.assertGreater(len(pkts), 0)
         self.pg1.add_stream(pkts)
@@ -3040,10 +3299,10 @@ class TestNAT44EDMW(TestNAT44ED):
         self.assertGreater(server3_n, 0)
 
         local = {
-            'addr': server2.ip4,
-            'port': local_port,
-            'probability': 10,
-            'vrf_id': 0
+            "addr": server2.ip4,
+            "port": local_port,
+            "probability": 10,
+            "vrf_id": 0,
         }
 
         # remove one back-end
@@ -3052,7 +3311,8 @@ class TestNAT44EDMW(TestNAT44ED):
             external_addr=external_addr,
             external_port=external_port,
             local=local,
-            protocol=IP_PROTOS.tcp)
+            protocol=IP_PROTOS.tcp,
+        )
         server1_n = 0
         server2_n = 0
         server3_n = 0
@@ -3075,39 +3335,39 @@ class TestNAT44EDMW(TestNAT44ED):
     # setting syslog sender cannot be undone and if it is set, it messes
     # with self.send_and_assert_no_replies functionality
     def test_zzz_syslog_sess(self):
-        """ NAT44ED Test syslog session creation and deletion """
-        self.vapi.syslog_set_filter(
-            self.syslog_severity.SYSLOG_API_SEVERITY_INFO)
+        """NAT44ED Test syslog session creation and deletion"""
+        self.vapi.syslog_set_filter(self.syslog_severity.SYSLOG_API_SEVERITY_INFO)
         self.vapi.syslog_set_sender(self.pg3.local_ip4, self.pg3.remote_ip4)
 
         self.nat_add_address(self.nat_addr)
         self.nat_add_inside_interface(self.pg0)
         self.nat_add_outside_interface(self.pg1)
 
-        p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
-             IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
-             TCP(sport=self.tcp_port_in, dport=self.tcp_external_port))
+        p = (
+            Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac)
+            / IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4)
+            / TCP(sport=self.tcp_port_in, dport=self.tcp_external_port)
+        )
         self.pg0.add_stream(p)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
         capture = self.pg1.get_capture(1)
         self.tcp_port_out = capture[0][TCP].sport
         capture = self.pg3.get_capture(1)
-        self.verify_syslog_sess(capture[0][Raw].load, 'SADD')
+        self.verify_syslog_sess(capture[0][Raw].load, "SADD")
 
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
         self.nat_add_address(self.nat_addr, is_add=0)
         capture = self.pg3.get_capture(1)
-        self.verify_syslog_sess(capture[0][Raw].load, 'SDEL')
+        self.verify_syslog_sess(capture[0][Raw].load, "SDEL")
 
     # put zzz in front of syslog test name so that it runs as a last test
     # setting syslog sender cannot be undone and if it is set, it messes
     # with self.send_and_assert_no_replies functionality
     def test_zzz_syslog_sess_reopen(self):
-        """ Syslog events for session reopen """
-        self.vapi.syslog_set_filter(
-            self.syslog_severity.SYSLOG_API_SEVERITY_INFO)
+        """Syslog events for session reopen"""
+        self.vapi.syslog_set_filter(self.syslog_severity.SYSLOG_API_SEVERITY_INFO)
         self.vapi.syslog_set_sender(self.pg3.local_ip4, self.pg3.remote_ip4)
 
         self.nat_add_address(self.nat_addr)
@@ -3115,55 +3375,62 @@ class TestNAT44EDMW(TestNAT44ED):
         self.nat_add_outside_interface(self.pg1)
 
         # SYN in2out
-        p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
-             IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
-             TCP(sport=self.tcp_port_in, dport=self.tcp_external_port))
+        p = (
+            Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac)
+            / IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4)
+            / TCP(sport=self.tcp_port_in, dport=self.tcp_external_port)
+        )
         capture = self.send_and_expect(self.pg0, p, self.pg1)[0]
         self.tcp_port_out = capture[0][TCP].sport
         capture = self.pg3.get_capture(1)
-        self.verify_syslog_sess(capture[0][Raw].load, 'SADD')
+        self.verify_syslog_sess(capture[0][Raw].load, "SADD")
 
         # SYN out2in
-        p = (Ether(dst=self.pg1.local_mac, src=self.pg1.remote_mac) /
-             IP(src=self.pg1.remote_ip4, dst=self.nat_addr) /
-             TCP(sport=self.tcp_external_port, dport=self.tcp_port_out,
-                 flags='SA'))
+        p = (
+            Ether(dst=self.pg1.local_mac, src=self.pg1.remote_mac)
+            / IP(src=self.pg1.remote_ip4, dst=self.nat_addr)
+            / TCP(sport=self.tcp_external_port, dport=self.tcp_port_out, flags="SA")
+        )
         self.send_and_expect(self.pg1, p, self.pg0)
 
-        p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
-             IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
-             TCP(sport=self.tcp_port_in, dport=self.tcp_external_port,
-                 flags="A"))
+        p = (
+            Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac)
+            / IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4)
+            / TCP(sport=self.tcp_port_in, dport=self.tcp_external_port, flags="A")
+        )
         self.send_and_expect(self.pg0, p, self.pg1)
 
         # FIN in2out
-        p = (Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac) /
-             IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
-             TCP(sport=self.tcp_port_in, dport=self.tcp_external_port,
-                 flags="F"))
+        p = (
+            Ether(dst=self.pg0.local_mac, src=self.pg0.remote_mac)
+            / IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4)
+            / TCP(sport=self.tcp_port_in, dport=self.tcp_external_port, flags="F")
+        )
         self.send_and_expect(self.pg0, p, self.pg1)
 
         # FIN out2in
-        p = (Ether(dst=self.pg1.local_mac, src=self.pg1.remote_mac) /
-             IP(src=self.pg1.remote_ip4, dst=self.nat_addr) /
-             TCP(sport=self.tcp_external_port, dport=self.tcp_port_out,
-                 flags="F"))
+        p = (
+            Ether(dst=self.pg1.local_mac, src=self.pg1.remote_mac)
+            / IP(src=self.pg1.remote_ip4, dst=self.nat_addr)
+            / TCP(sport=self.tcp_external_port, dport=self.tcp_port_out, flags="F")
+        )
         self.send_and_expect(self.pg1, p, self.pg0)
 
-        self.init_tcp_session(self.pg0, self.pg1, self.tcp_port_in,
-                              self.tcp_external_port)
+        self.init_tcp_session(
+            self.pg0, self.pg1, self.tcp_port_in, self.tcp_external_port
+        )
 
         # 2 records should be produced - first one del & add
         capture = self.pg3.get_capture(2)
-        self.verify_syslog_sess(capture[0][Raw].load, 'SDEL')
-        self.verify_syslog_sess(capture[1][Raw].load, 'SADD')
+        self.verify_syslog_sess(capture[0][Raw].load, "SDEL")
+        self.verify_syslog_sess(capture[1][Raw].load, "SADD")
 
     def test_twice_nat_interface_addr(self):
-        """ NAT44ED Acquire twice NAT addresses from interface """
+        """NAT44ED Acquire twice NAT addresses from interface"""
         flags = self.config_flags.NAT_IS_TWICE_NAT
         self.vapi.nat44_add_del_interface_addr(
-            sw_if_index=self.pg11.sw_if_index,
-            flags=flags, is_add=1)
+            sw_if_index=self.pg11.sw_if_index, flags=flags, is_add=1
+        )
 
         # no address in NAT pool
         adresses = self.vapi.nat44_address_dump()
@@ -3173,8 +3440,7 @@ class TestNAT44EDMW(TestNAT44ED):
         self.pg11.config_ip4()
         adresses = self.vapi.nat44_address_dump()
         self.assertEqual(1, len(adresses))
-        self.assertEqual(str(adresses[0].ip_address),
-                         self.pg11.local_ip4)
+        self.assertEqual(str(adresses[0].ip_address), self.pg11.local_ip4)
         self.assertEqual(adresses[0].flags, flags)
 
         # remove interface address and check NAT address pool
@@ -3183,11 +3449,12 @@ class TestNAT44EDMW(TestNAT44ED):
         self.assertEqual(0, len(adresses))
 
     def test_output_feature_stateful_acl(self):
-        """ NAT44ED output feature works with stateful ACL """
+        """NAT44ED output feature works with stateful ACL"""
 
         self.nat_add_address(self.nat_addr)
         self.vapi.nat44_ed_add_del_output_interface(
-            sw_if_index=self.pg1.sw_if_index, is_add=1)
+            sw_if_index=self.pg1.sw_if_index, is_add=1
+        )
 
         # First ensure that the NAT is working sans ACL
 
@@ -3197,14 +3464,16 @@ class TestNAT44EDMW(TestNAT44ED):
 
         # send packets into inside intf, ensure received via outside intf
         pkts_in2out = self.create_stream_in(self.pg0, self.pg1)
-        capture = self.send_and_expect(self.pg0, pkts_in2out, self.pg1,
-                                       len(pkts_in2out))
+        capture = self.send_and_expect(
+            self.pg0, pkts_in2out, self.pg1, len(pkts_in2out)
+        )
         self.verify_capture_out(capture, ignore_port=True)
 
         # send out2in again, with sessions created it should work now
         pkts_out2in = self.create_stream_out(self.pg1)
-        capture = self.send_and_expect(self.pg1, pkts_out2in, self.pg0,
-                                       len(pkts_out2in))
+        capture = self.send_and_expect(
+            self.pg1, pkts_out2in, self.pg0, len(pkts_out2in)
+        )
         self.verify_capture_in(capture, self.pg0)
 
         # Create an ACL blocking everything
@@ -3218,8 +3487,9 @@ class TestNAT44EDMW(TestNAT44ED):
         in2out_acl.add_vpp_config()
 
         # apply as input acl on interface and confirm it blocks everything
-        acl_if = VppAclInterface(self, sw_if_index=self.pg1.sw_if_index,
-                                 n_input=1, acls=[out2in_acl])
+        acl_if = VppAclInterface(
+            self, sw_if_index=self.pg1.sw_if_index, n_input=1, acls=[out2in_acl]
+        )
         acl_if.add_vpp_config()
         self.send_and_assert_no_replies(self.pg1, pkts_out2in)
 
@@ -3227,8 +3497,9 @@ class TestNAT44EDMW(TestNAT44ED):
         acl_if.acls = [out2in_acl, in2out_acl]
         acl_if.add_vpp_config()
         # send in2out to generate ACL state (NAT state was created earlier)
-        capture = self.send_and_expect(self.pg0, pkts_in2out, self.pg1,
-                                       len(pkts_in2out))
+        capture = self.send_and_expect(
+            self.pg0, pkts_in2out, self.pg1, len(pkts_in2out)
+        )
         self.verify_capture_out(capture, ignore_port=True)
 
         # send out2in again. ACL state exists so it should work now.
@@ -3236,13 +3507,14 @@ class TestNAT44EDMW(TestNAT44ED):
         for p in pkts_out2in:
             if p.haslayer(TCP) and p[TCP].flags & 0x02:
                 p[TCP].flags |= 0x10
-        capture = self.send_and_expect(self.pg1, pkts_out2in, self.pg0,
-                                       len(pkts_out2in))
+        capture = self.send_and_expect(
+            self.pg1, pkts_out2in, self.pg0, len(pkts_out2in)
+        )
         self.verify_capture_in(capture, self.pg0)
         self.logger.info(self.vapi.cli("show trace"))
 
     def test_tcp_close(self):
-        """ NAT44ED Close TCP session from inside network - output feature """
+        """NAT44ED Close TCP session from inside network - output feature"""
         config = self.vapi.nat44_show_running_config()
         old_timeouts = config.timeouts
         new_transitory = 2
@@ -3250,77 +3522,92 @@ class TestNAT44EDMW(TestNAT44ED):
             udp=old_timeouts.udp,
             tcp_established=old_timeouts.tcp_established,
             icmp=old_timeouts.icmp,
-            tcp_transitory=new_transitory)
+            tcp_transitory=new_transitory,
+        )
 
         self.vapi.nat44_forwarding_enable_disable(enable=1)
         self.nat_add_address(self.pg1.local_ip4)
-        twice_nat_addr = '10.0.1.3'
-        service_ip = '192.168.16.150'
+        twice_nat_addr = "10.0.1.3"
+        service_ip = "192.168.16.150"
         self.nat_add_address(twice_nat_addr, twice_nat=1)
 
         flags = self.config_flags.NAT_IS_INSIDE
         self.vapi.nat44_interface_add_del_feature(
-            sw_if_index=self.pg0.sw_if_index,
-            is_add=1)
+            sw_if_index=self.pg0.sw_if_index, is_add=1
+        )
         self.vapi.nat44_interface_add_del_feature(
-            sw_if_index=self.pg0.sw_if_index,
-            flags=flags, is_add=1)
+            sw_if_index=self.pg0.sw_if_index, flags=flags, is_add=1
+        )
         self.vapi.nat44_ed_add_del_output_interface(
-            is_add=1,
-            sw_if_index=self.pg1.sw_if_index)
-
-        flags = (self.config_flags.NAT_IS_OUT2IN_ONLY |
-                 self.config_flags.NAT_IS_TWICE_NAT)
-        self.nat_add_static_mapping(self.pg0.remote_ip4,
-                                    service_ip, 80, 80,
-                                    proto=IP_PROTOS.tcp,
-                                    flags=flags)
+            is_add=1, sw_if_index=self.pg1.sw_if_index
+        )
+
+        flags = (
+            self.config_flags.NAT_IS_OUT2IN_ONLY | self.config_flags.NAT_IS_TWICE_NAT
+        )
+        self.nat_add_static_mapping(
+            self.pg0.remote_ip4, service_ip, 80, 80, proto=IP_PROTOS.tcp, flags=flags
+        )
         sessions = self.vapi.nat44_user_session_dump(self.pg0.remote_ip4, 0)
         start_sessnum = len(sessions)
 
         # SYN packet out->in
-        p = (Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac) /
-             IP(src=self.pg1.remote_ip4, dst=service_ip) /
-             TCP(sport=33898, dport=80, flags="S"))
+        p = (
+            Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac)
+            / IP(src=self.pg1.remote_ip4, dst=service_ip)
+            / TCP(sport=33898, dport=80, flags="S")
+        )
         capture = self.send_and_expect(self.pg1, p, self.pg0, n_rx=1)
         p = capture[0]
         tcp_port = p[TCP].sport
 
         # SYN + ACK packet in->out
-        p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
-             IP(src=self.pg0.remote_ip4, dst=twice_nat_addr) /
-             TCP(sport=80, dport=tcp_port, flags="SA"))
+        p = (
+            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+            / IP(src=self.pg0.remote_ip4, dst=twice_nat_addr)
+            / TCP(sport=80, dport=tcp_port, flags="SA")
+        )
         self.send_and_expect(self.pg0, p, self.pg1, n_rx=1)
 
         # ACK packet out->in
-        p = (Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac) /
-             IP(src=self.pg1.remote_ip4, dst=service_ip) /
-             TCP(sport=33898, dport=80, flags="A"))
+        p = (
+            Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac)
+            / IP(src=self.pg1.remote_ip4, dst=service_ip)
+            / TCP(sport=33898, dport=80, flags="A")
+        )
         self.send_and_expect(self.pg1, p, self.pg0, n_rx=1)
 
         # FIN packet in -> out
-        p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
-             IP(src=self.pg0.remote_ip4, dst=twice_nat_addr) /
-             TCP(sport=80, dport=tcp_port, flags="FA", seq=100, ack=300))
+        p = (
+            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+            / IP(src=self.pg0.remote_ip4, dst=twice_nat_addr)
+            / TCP(sport=80, dport=tcp_port, flags="FA", seq=100, ack=300)
+        )
         self.send_and_expect(self.pg0, p, self.pg1, n_rx=1)
 
         # FIN+ACK packet out -> in
-        p = (Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac) /
-             IP(src=self.pg1.remote_ip4, dst=service_ip) /
-             TCP(sport=33898, dport=80, flags="FA", seq=300, ack=101))
+        p = (
+            Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac)
+            / IP(src=self.pg1.remote_ip4, dst=service_ip)
+            / TCP(sport=33898, dport=80, flags="FA", seq=300, ack=101)
+        )
         self.send_and_expect(self.pg1, p, self.pg0, n_rx=1)
 
         # ACK packet in -> out
-        p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
-             IP(src=self.pg0.remote_ip4, dst=twice_nat_addr) /
-             TCP(sport=80, dport=tcp_port, flags="A", seq=101, ack=301))
+        p = (
+            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+            / IP(src=self.pg0.remote_ip4, dst=twice_nat_addr)
+            / TCP(sport=80, dport=tcp_port, flags="A", seq=101, ack=301)
+        )
         self.send_and_expect(self.pg0, p, self.pg1, n_rx=1)
 
         # session now in transitory timeout, but traffic still flows
         # try FIN packet out->in
-        p = (Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac) /
-             IP(src=self.pg1.remote_ip4, dst=service_ip) /
-             TCP(sport=33898, dport=80, flags="F"))
+        p = (
+            Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac)
+            / IP(src=self.pg1.remote_ip4, dst=service_ip)
+            / TCP(sport=33898, dport=80, flags="F")
+        )
         self.pg1.add_stream(p)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
@@ -3334,15 +3621,17 @@ class TestNAT44EDMW(TestNAT44ED):
 
         # send FIN+ACK packet out -> in - will cause session to be wiped
         # but won't create a new session
-        p = (Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac) /
-             IP(src=self.pg1.remote_ip4, dst=service_ip) /
-             TCP(sport=33898, dport=80, flags="FA", seq=300, ack=101))
+        p = (
+            Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac)
+            / IP(src=self.pg1.remote_ip4, dst=service_ip)
+            / TCP(sport=33898, dport=80, flags="FA", seq=300, ack=101)
+        )
         self.send_and_assert_no_replies(self.pg1, p)
         sessions = self.vapi.nat44_user_session_dump(self.pg0.remote_ip4, 0)
         self.assertEqual(len(sessions) - start_sessnum, 0)
 
     def test_tcp_session_close_in(self):
-        """ NAT44ED Close TCP session from inside network """
+        """NAT44ED Close TCP session from inside network"""
 
         in_port = self.tcp_port_in
         out_port = 10505
@@ -3351,79 +3640,92 @@ class TestNAT44EDMW(TestNAT44ED):
         self.nat_add_address(self.nat_addr)
         self.nat_add_inside_interface(self.pg0)
         self.nat_add_outside_interface(self.pg1)
-        self.nat_add_static_mapping(self.pg0.remote_ip4, self.nat_addr,
-                                    in_port, out_port, proto=IP_PROTOS.tcp,
-                                    flags=self.config_flags.NAT_IS_TWICE_NAT)
+        self.nat_add_static_mapping(
+            self.pg0.remote_ip4,
+            self.nat_addr,
+            in_port,
+            out_port,
+            proto=IP_PROTOS.tcp,
+            flags=self.config_flags.NAT_IS_TWICE_NAT,
+        )
 
         sessions = self.vapi.nat44_user_session_dump(self.pg0.remote_ip4, 0)
         session_n = len(sessions)
 
-        self.vapi.nat_set_timeouts(udp=300, tcp_established=7440,
-                                   tcp_transitory=2, icmp=5)
+        self.vapi.nat_set_timeouts(
+            udp=300, tcp_established=7440, tcp_transitory=2, icmp=5
+        )
 
         self.init_tcp_session(self.pg0, self.pg1, in_port, ext_port)
 
         # FIN packet in -> out
-        p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
-             IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
-             TCP(sport=in_port, dport=ext_port,
-                 flags="FA", seq=100, ack=300))
+        p = (
+            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+            / IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4)
+            / TCP(sport=in_port, dport=ext_port, flags="FA", seq=100, ack=300)
+        )
         self.send_and_expect(self.pg0, p, self.pg1)
         pkts = []
 
         # ACK packet out -> in
-        p = (Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac) /
-             IP(src=self.pg1.remote_ip4, dst=self.nat_addr) /
-             TCP(sport=ext_port, dport=out_port,
-                 flags="A", seq=300, ack=101))
+        p = (
+            Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac)
+            / IP(src=self.pg1.remote_ip4, dst=self.nat_addr)
+            / TCP(sport=ext_port, dport=out_port, flags="A", seq=300, ack=101)
+        )
         pkts.append(p)
 
         # FIN packet out -> in
-        p = (Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac) /
-             IP(src=self.pg1.remote_ip4, dst=self.nat_addr) /
-             TCP(sport=ext_port, dport=out_port,
-                 flags="FA", seq=300, ack=101))
+        p = (
+            Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac)
+            / IP(src=self.pg1.remote_ip4, dst=self.nat_addr)
+            / TCP(sport=ext_port, dport=out_port, flags="FA", seq=300, ack=101)
+        )
         pkts.append(p)
 
         self.send_and_expect(self.pg1, pkts, self.pg0)
 
         # ACK packet in -> out
-        p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
-             IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
-             TCP(sport=in_port, dport=ext_port,
-                 flags="A", seq=101, ack=301))
+        p = (
+            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+            / IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4)
+            / TCP(sport=in_port, dport=ext_port, flags="A", seq=101, ack=301)
+        )
         self.send_and_expect(self.pg0, p, self.pg1)
 
         sessions = self.vapi.nat44_user_session_dump(self.pg0.remote_ip4, 0)
         self.assertEqual(len(sessions) - session_n, 1)
 
         # retransmit FIN packet out -> in
-        p = (Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac) /
-             IP(src=self.pg1.remote_ip4, dst=self.nat_addr) /
-             TCP(sport=ext_port, dport=out_port,
-                 flags="FA", seq=300, ack=101))
+        p = (
+            Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac)
+            / IP(src=self.pg1.remote_ip4, dst=self.nat_addr)
+            / TCP(sport=ext_port, dport=out_port, flags="FA", seq=300, ack=101)
+        )
 
         self.send_and_expect(self.pg1, p, self.pg0)
 
         # retransmit ACK packet in -> out
-        p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
-             IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
-             TCP(sport=in_port, dport=ext_port,
-                 flags="A", seq=101, ack=301))
+        p = (
+            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+            / IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4)
+            / TCP(sport=in_port, dport=ext_port, flags="A", seq=101, ack=301)
+        )
         self.send_and_expect(self.pg0, p, self.pg1)
 
         self.virtual_sleep(3)
         # retransmit ACK packet in -> out - this will cause session to be wiped
-        p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
-             IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
-             TCP(sport=in_port, dport=ext_port,
-                 flags="A", seq=101, ack=301))
+        p = (
+            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+            / IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4)
+            / TCP(sport=in_port, dport=ext_port, flags="A", seq=101, ack=301)
+        )
         self.send_and_assert_no_replies(self.pg0, p)
         sessions = self.vapi.nat44_user_session_dump(self.pg0.remote_ip4, 0)
         self.assertEqual(len(sessions) - session_n, 0)
 
     def test_tcp_session_close_out(self):
-        """ NAT44ED Close TCP session from outside network """
+        """NAT44ED Close TCP session from outside network"""
 
         in_port = self.tcp_port_in
         out_port = 10505
@@ -3432,33 +3734,41 @@ class TestNAT44EDMW(TestNAT44ED):
         self.nat_add_address(self.nat_addr)
         self.nat_add_inside_interface(self.pg0)
         self.nat_add_outside_interface(self.pg1)
-        self.nat_add_static_mapping(self.pg0.remote_ip4, self.nat_addr,
-                                    in_port, out_port, proto=IP_PROTOS.tcp,
-                                    flags=self.config_flags.NAT_IS_TWICE_NAT)
+        self.nat_add_static_mapping(
+            self.pg0.remote_ip4,
+            self.nat_addr,
+            in_port,
+            out_port,
+            proto=IP_PROTOS.tcp,
+            flags=self.config_flags.NAT_IS_TWICE_NAT,
+        )
 
         sessions = self.vapi.nat44_user_session_dump(self.pg0.remote_ip4, 0)
         session_n = len(sessions)
 
-        self.vapi.nat_set_timeouts(udp=300, tcp_established=7440,
-                                   tcp_transitory=2, icmp=5)
+        self.vapi.nat_set_timeouts(
+            udp=300, tcp_established=7440, tcp_transitory=2, icmp=5
+        )
 
         _ = self.init_tcp_session(self.pg0, self.pg1, in_port, ext_port)
 
         # FIN packet out -> in
-        p = (Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac) /
-             IP(src=self.pg1.remote_ip4, dst=self.nat_addr) /
-             TCP(sport=ext_port, dport=out_port,
-                 flags="FA", seq=100, ack=300))
+        p = (
+            Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac)
+            / IP(src=self.pg1.remote_ip4, dst=self.nat_addr)
+            / TCP(sport=ext_port, dport=out_port, flags="FA", seq=100, ack=300)
+        )
         self.pg1.add_stream(p)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
         self.pg0.get_capture(1)
 
         # FIN+ACK packet in -> out
-        p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
-             IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
-             TCP(sport=in_port, dport=ext_port,
-                 flags="FA", seq=300, ack=101))
+        p = (
+            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+            / IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4)
+            / TCP(sport=in_port, dport=ext_port, flags="FA", seq=300, ack=101)
+        )
 
         self.pg0.add_stream(p)
         self.pg_enable_capture(self.pg_interfaces)
@@ -3466,10 +3776,11 @@ class TestNAT44EDMW(TestNAT44ED):
         self.pg1.get_capture(1)
 
         # ACK packet out -> in
-        p = (Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac) /
-             IP(src=self.pg1.remote_ip4, dst=self.nat_addr) /
-             TCP(sport=ext_port, dport=out_port,
-                 flags="A", seq=101, ack=301))
+        p = (
+            Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac)
+            / IP(src=self.pg1.remote_ip4, dst=self.nat_addr)
+            / TCP(sport=ext_port, dport=out_port, flags="A", seq=101, ack=301)
+        )
         self.pg1.add_stream(p)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
@@ -3479,31 +3790,34 @@ class TestNAT44EDMW(TestNAT44ED):
         self.assertEqual(len(sessions) - session_n, 1)
 
         # retransmit FIN packet out -> in
-        p = (Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac) /
-             IP(src=self.pg1.remote_ip4, dst=self.nat_addr) /
-             TCP(sport=ext_port, dport=out_port,
-                 flags="FA", seq=300, ack=101))
+        p = (
+            Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac)
+            / IP(src=self.pg1.remote_ip4, dst=self.nat_addr)
+            / TCP(sport=ext_port, dport=out_port, flags="FA", seq=300, ack=101)
+        )
         self.send_and_expect(self.pg1, p, self.pg0)
 
         # retransmit ACK packet in -> out
-        p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
-             IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
-             TCP(sport=in_port, dport=ext_port,
-                 flags="A", seq=101, ack=301))
+        p = (
+            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+            / IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4)
+            / TCP(sport=in_port, dport=ext_port, flags="A", seq=101, ack=301)
+        )
         self.send_and_expect(self.pg0, p, self.pg1)
 
         self.virtual_sleep(3)
         # retransmit ACK packet in -> out - this will cause session to be wiped
-        p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
-             IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
-             TCP(sport=in_port, dport=ext_port,
-                 flags="A", seq=101, ack=301))
+        p = (
+            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+            / IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4)
+            / TCP(sport=in_port, dport=ext_port, flags="A", seq=101, ack=301)
+        )
         self.send_and_assert_no_replies(self.pg0, p)
         sessions = self.vapi.nat44_user_session_dump(self.pg0.remote_ip4, 0)
         self.assertEqual(len(sessions) - session_n, 0)
 
     def test_tcp_session_close_simultaneous(self):
-        """ Simultaneous TCP close from both sides """
+        """Simultaneous TCP close from both sides"""
 
         in_port = self.tcp_port_in
         ext_port = 10505
@@ -3511,252 +3825,297 @@ class TestNAT44EDMW(TestNAT44ED):
         self.nat_add_address(self.nat_addr)
         self.nat_add_inside_interface(self.pg0)
         self.nat_add_outside_interface(self.pg1)
-        self.nat_add_static_mapping(self.pg0.remote_ip4, self.nat_addr,
-                                    in_port, ext_port, proto=IP_PROTOS.tcp,
-                                    flags=self.config_flags.NAT_IS_TWICE_NAT)
+        self.nat_add_static_mapping(
+            self.pg0.remote_ip4,
+            self.nat_addr,
+            in_port,
+            ext_port,
+            proto=IP_PROTOS.tcp,
+            flags=self.config_flags.NAT_IS_TWICE_NAT,
+        )
 
         sessions = self.vapi.nat44_user_session_dump(self.pg0.remote_ip4, 0)
         session_n = len(sessions)
 
-        self.vapi.nat_set_timeouts(udp=300, tcp_established=7440,
-                                   tcp_transitory=2, icmp=5)
+        self.vapi.nat_set_timeouts(
+            udp=300, tcp_established=7440, tcp_transitory=2, icmp=5
+        )
 
         out_port = self.init_tcp_session(self.pg0, self.pg1, in_port, ext_port)
 
         # FIN packet in -> out
-        p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
-             IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
-             TCP(sport=in_port, dport=ext_port,
-                 flags="FA", seq=100, ack=300))
+        p = (
+            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+            / IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4)
+            / TCP(sport=in_port, dport=ext_port, flags="FA", seq=100, ack=300)
+        )
         self.send_and_expect(self.pg0, p, self.pg1)
 
         # FIN packet out -> in
-        p = (Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac) /
-             IP(src=self.pg1.remote_ip4, dst=self.nat_addr) /
-             TCP(sport=ext_port, dport=out_port,
-                 flags="FA", seq=300, ack=100))
+        p = (
+            Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac)
+            / IP(src=self.pg1.remote_ip4, dst=self.nat_addr)
+            / TCP(sport=ext_port, dport=out_port, flags="FA", seq=300, ack=100)
+        )
         self.send_and_expect(self.pg1, p, self.pg0)
 
         # ACK packet in -> out
-        p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
-             IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
-             TCP(sport=in_port, dport=ext_port,
-                 flags="A", seq=101, ack=301))
+        p = (
+            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+            / IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4)
+            / TCP(sport=in_port, dport=ext_port, flags="A", seq=101, ack=301)
+        )
         self.send_and_expect(self.pg0, p, self.pg1)
 
         # ACK packet out -> in
-        p = (Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac) /
-             IP(src=self.pg1.remote_ip4, dst=self.nat_addr) /
-             TCP(sport=ext_port, dport=out_port,
-                 flags="A", seq=301, ack=101))
+        p = (
+            Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac)
+            / IP(src=self.pg1.remote_ip4, dst=self.nat_addr)
+            / TCP(sport=ext_port, dport=out_port, flags="A", seq=301, ack=101)
+        )
         self.send_and_expect(self.pg1, p, self.pg0)
 
         sessions = self.vapi.nat44_user_session_dump(self.pg0.remote_ip4, 0)
         self.assertEqual(len(sessions) - session_n, 1)
 
         # retransmit FIN packet out -> in
-        p = (Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac) /
-             IP(src=self.pg1.remote_ip4, dst=self.nat_addr) /
-             TCP(sport=ext_port, dport=out_port,
-                 flags="FA", seq=300, ack=101))
+        p = (
+            Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac)
+            / IP(src=self.pg1.remote_ip4, dst=self.nat_addr)
+            / TCP(sport=ext_port, dport=out_port, flags="FA", seq=300, ack=101)
+        )
         self.send_and_expect(self.pg1, p, self.pg0)
 
         # retransmit ACK packet in -> out
-        p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
-             IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
-             TCP(sport=in_port, dport=ext_port,
-                 flags="A", seq=101, ack=301))
+        p = (
+            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+            / IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4)
+            / TCP(sport=in_port, dport=ext_port, flags="A", seq=101, ack=301)
+        )
         self.send_and_expect(self.pg0, p, self.pg1)
 
         self.virtual_sleep(3)
         # retransmit ACK packet in -> out - this will cause session to be wiped
-        p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
-             IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
-             TCP(sport=in_port, dport=ext_port,
-                 flags="A", seq=101, ack=301))
+        p = (
+            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+            / IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4)
+            / TCP(sport=in_port, dport=ext_port, flags="A", seq=101, ack=301)
+        )
         self.pg_send(self.pg0, p)
         self.send_and_assert_no_replies(self.pg0, p)
         sessions = self.vapi.nat44_user_session_dump(self.pg0.remote_ip4, 0)
         self.assertEqual(len(sessions) - session_n, 0)
 
     def test_tcp_session_half_reopen_inside(self):
-        """ TCP session in FIN/FIN state not reopened by in2out SYN only """
+        """TCP session in FIN/FIN state not reopened by in2out SYN only"""
         in_port = self.tcp_port_in
         ext_port = 10505
 
         self.nat_add_address(self.nat_addr)
         self.nat_add_inside_interface(self.pg0)
         self.nat_add_outside_interface(self.pg1)
-        self.nat_add_static_mapping(self.pg0.remote_ip4, self.nat_addr,
-                                    in_port, ext_port, proto=IP_PROTOS.tcp,
-                                    flags=self.config_flags.NAT_IS_TWICE_NAT)
+        self.nat_add_static_mapping(
+            self.pg0.remote_ip4,
+            self.nat_addr,
+            in_port,
+            ext_port,
+            proto=IP_PROTOS.tcp,
+            flags=self.config_flags.NAT_IS_TWICE_NAT,
+        )
 
         sessions = self.vapi.nat44_user_session_dump(self.pg0.remote_ip4, 0)
         session_n = len(sessions)
 
-        self.vapi.nat_set_timeouts(udp=300, tcp_established=7440,
-                                   tcp_transitory=2, icmp=5)
+        self.vapi.nat_set_timeouts(
+            udp=300, tcp_established=7440, tcp_transitory=2, icmp=5
+        )
 
         out_port = self.init_tcp_session(self.pg0, self.pg1, in_port, ext_port)
 
         # FIN packet in -> out
-        p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
-             IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
-             TCP(sport=in_port, dport=ext_port,
-                 flags="FA", seq=100, ack=300))
+        p = (
+            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+            / IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4)
+            / TCP(sport=in_port, dport=ext_port, flags="FA", seq=100, ack=300)
+        )
         self.send_and_expect(self.pg0, p, self.pg1)
 
         # FIN packet out -> in
-        p = (Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac) /
-             IP(src=self.pg1.remote_ip4, dst=self.nat_addr) /
-             TCP(sport=ext_port, dport=out_port,
-                 flags="FA", seq=300, ack=100))
+        p = (
+            Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac)
+            / IP(src=self.pg1.remote_ip4, dst=self.nat_addr)
+            / TCP(sport=ext_port, dport=out_port, flags="FA", seq=300, ack=100)
+        )
         self.send_and_expect(self.pg1, p, self.pg0)
 
         sessions = self.vapi.nat44_user_session_dump(self.pg0.remote_ip4, 0)
         self.assertEqual(len(sessions) - session_n, 1)
 
         # send SYN packet in -> out
-        p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
-             IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
-             TCP(sport=in_port, dport=ext_port,
-                 flags="S", seq=101, ack=301))
+        p = (
+            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+            / IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4)
+            / TCP(sport=in_port, dport=ext_port, flags="S", seq=101, ack=301)
+        )
         self.send_and_expect(self.pg0, p, self.pg1)
 
         self.virtual_sleep(3)
         # send ACK packet in -> out - session should be wiped
-        p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
-             IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
-             TCP(sport=in_port, dport=ext_port,
-                 flags="A", seq=101, ack=301))
+        p = (
+            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+            / IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4)
+            / TCP(sport=in_port, dport=ext_port, flags="A", seq=101, ack=301)
+        )
         self.send_and_assert_no_replies(self.pg0, p, self.pg1)
         sessions = self.vapi.nat44_user_session_dump(self.pg0.remote_ip4, 0)
         self.assertEqual(len(sessions) - session_n, 0)
 
     def test_tcp_session_half_reopen_outside(self):
-        """ TCP session in FIN/FIN state not reopened by out2in SYN only """
+        """TCP session in FIN/FIN state not reopened by out2in SYN only"""
         in_port = self.tcp_port_in
         ext_port = 10505
 
         self.nat_add_address(self.nat_addr)
         self.nat_add_inside_interface(self.pg0)
         self.nat_add_outside_interface(self.pg1)
-        self.nat_add_static_mapping(self.pg0.remote_ip4, self.nat_addr,
-                                    in_port, ext_port, proto=IP_PROTOS.tcp,
-                                    flags=self.config_flags.NAT_IS_TWICE_NAT)
+        self.nat_add_static_mapping(
+            self.pg0.remote_ip4,
+            self.nat_addr,
+            in_port,
+            ext_port,
+            proto=IP_PROTOS.tcp,
+            flags=self.config_flags.NAT_IS_TWICE_NAT,
+        )
 
         sessions = self.vapi.nat44_user_session_dump(self.pg0.remote_ip4, 0)
         session_n = len(sessions)
 
-        self.vapi.nat_set_timeouts(udp=300, tcp_established=7440,
-                                   tcp_transitory=2, icmp=5)
+        self.vapi.nat_set_timeouts(
+            udp=300, tcp_established=7440, tcp_transitory=2, icmp=5
+        )
 
         out_port = self.init_tcp_session(self.pg0, self.pg1, in_port, ext_port)
 
         # FIN packet in -> out
-        p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
-             IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
-             TCP(sport=in_port, dport=ext_port,
-                 flags="FA", seq=100, ack=300))
+        p = (
+            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+            / IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4)
+            / TCP(sport=in_port, dport=ext_port, flags="FA", seq=100, ack=300)
+        )
         self.send_and_expect(self.pg0, p, self.pg1)
 
         # FIN packet out -> in
-        p = (Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac) /
-             IP(src=self.pg1.remote_ip4, dst=self.nat_addr) /
-             TCP(sport=ext_port, dport=out_port,
-                 flags="FA", seq=300, ack=100))
+        p = (
+            Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac)
+            / IP(src=self.pg1.remote_ip4, dst=self.nat_addr)
+            / TCP(sport=ext_port, dport=out_port, flags="FA", seq=300, ack=100)
+        )
         self.send_and_expect(self.pg1, p, self.pg0)
 
         sessions = self.vapi.nat44_user_session_dump(self.pg0.remote_ip4, 0)
         self.assertEqual(len(sessions) - session_n, 1)
 
         # send SYN packet out -> in
-        p = (Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac) /
-             IP(src=self.pg1.remote_ip4, dst=self.nat_addr) /
-             TCP(sport=ext_port, dport=out_port,
-                 flags="S", seq=300, ack=101))
+        p = (
+            Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac)
+            / IP(src=self.pg1.remote_ip4, dst=self.nat_addr)
+            / TCP(sport=ext_port, dport=out_port, flags="S", seq=300, ack=101)
+        )
         self.send_and_expect(self.pg1, p, self.pg0)
 
         self.virtual_sleep(3)
         # send ACK packet in -> out - session should be wiped
-        p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
-             IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
-             TCP(sport=in_port, dport=ext_port,
-                 flags="A", seq=101, ack=301))
+        p = (
+            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+            / IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4)
+            / TCP(sport=in_port, dport=ext_port, flags="A", seq=101, ack=301)
+        )
         self.send_and_assert_no_replies(self.pg0, p, self.pg1)
         sessions = self.vapi.nat44_user_session_dump(self.pg0.remote_ip4, 0)
         self.assertEqual(len(sessions) - session_n, 0)
 
     def test_tcp_session_reopen(self):
-        """ TCP session in FIN/FIN state reopened by SYN from both sides """
+        """TCP session in FIN/FIN state reopened by SYN from both sides"""
         in_port = self.tcp_port_in
         ext_port = 10505
 
         self.nat_add_address(self.nat_addr)
         self.nat_add_inside_interface(self.pg0)
         self.nat_add_outside_interface(self.pg1)
-        self.nat_add_static_mapping(self.pg0.remote_ip4, self.nat_addr,
-                                    in_port, ext_port, proto=IP_PROTOS.tcp,
-                                    flags=self.config_flags.NAT_IS_TWICE_NAT)
+        self.nat_add_static_mapping(
+            self.pg0.remote_ip4,
+            self.nat_addr,
+            in_port,
+            ext_port,
+            proto=IP_PROTOS.tcp,
+            flags=self.config_flags.NAT_IS_TWICE_NAT,
+        )
 
         sessions = self.vapi.nat44_user_session_dump(self.pg0.remote_ip4, 0)
         session_n = len(sessions)
 
-        self.vapi.nat_set_timeouts(udp=300, tcp_established=7440,
-                                   tcp_transitory=2, icmp=5)
+        self.vapi.nat_set_timeouts(
+            udp=300, tcp_established=7440, tcp_transitory=2, icmp=5
+        )
 
         out_port = self.init_tcp_session(self.pg0, self.pg1, in_port, ext_port)
 
         # FIN packet in -> out
-        p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
-             IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
-             TCP(sport=in_port, dport=ext_port,
-                 flags="FA", seq=100, ack=300))
+        p = (
+            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+            / IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4)
+            / TCP(sport=in_port, dport=ext_port, flags="FA", seq=100, ack=300)
+        )
         self.send_and_expect(self.pg0, p, self.pg1)
 
         # FIN packet out -> in
-        p = (Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac) /
-             IP(src=self.pg1.remote_ip4, dst=self.nat_addr) /
-             TCP(sport=ext_port, dport=out_port,
-                 flags="FA", seq=300, ack=100))
+        p = (
+            Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac)
+            / IP(src=self.pg1.remote_ip4, dst=self.nat_addr)
+            / TCP(sport=ext_port, dport=out_port, flags="FA", seq=300, ack=100)
+        )
         self.send_and_expect(self.pg1, p, self.pg0)
 
         sessions = self.vapi.nat44_user_session_dump(self.pg0.remote_ip4, 0)
         self.assertEqual(len(sessions) - session_n, 1)
 
         # send SYN packet out -> in
-        p = (Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac) /
-             IP(src=self.pg1.remote_ip4, dst=self.nat_addr) /
-             TCP(sport=ext_port, dport=out_port,
-                 flags="S", seq=300, ack=101))
+        p = (
+            Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac)
+            / IP(src=self.pg1.remote_ip4, dst=self.nat_addr)
+            / TCP(sport=ext_port, dport=out_port, flags="S", seq=300, ack=101)
+        )
         self.send_and_expect(self.pg1, p, self.pg0)
 
         # send SYN packet in -> out
-        p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
-             IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
-             TCP(sport=in_port, dport=ext_port,
-                 flags="SA", seq=101, ack=301))
+        p = (
+            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+            / IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4)
+            / TCP(sport=in_port, dport=ext_port, flags="SA", seq=101, ack=301)
+        )
         self.send_and_expect(self.pg0, p, self.pg1)
 
         # send ACK packet out -> in
-        p = (Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac) /
-             IP(src=self.pg1.remote_ip4, dst=self.nat_addr) /
-             TCP(sport=ext_port, dport=out_port,
-                 flags="A", seq=300, ack=101))
+        p = (
+            Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac)
+            / IP(src=self.pg1.remote_ip4, dst=self.nat_addr)
+            / TCP(sport=ext_port, dport=out_port, flags="A", seq=300, ack=101)
+        )
         self.send_and_expect(self.pg1, p, self.pg0)
 
         self.virtual_sleep(3)
         # send ACK packet in -> out - should be forwarded and session alive
-        p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
-             IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
-             TCP(sport=in_port, dport=ext_port,
-                 flags="A", seq=101, ack=301))
+        p = (
+            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+            / IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4)
+            / TCP(sport=in_port, dport=ext_port, flags="A", seq=101, ack=301)
+        )
         self.send_and_expect(self.pg0, p, self.pg1)
         sessions = self.vapi.nat44_user_session_dump(self.pg0.remote_ip4, 0)
         self.assertEqual(len(sessions) - session_n, 1)
 
     def test_dynamic_vrf(self):
-        """ NAT44ED dynamic translation test: different VRF"""
+        """NAT44ED dynamic translation test: different VRF"""
 
         vrf_id_in = 33
         vrf_id_out = 34
@@ -3789,30 +4148,28 @@ class TestNAT44EDMW(TestNAT44ED):
             self.pg7.unconfig()
             self.pg8.unconfig()
 
-            self.vapi.ip_table_add_del(is_add=0,
-                                       table={'table_id': vrf_id_in})
-            self.vapi.ip_table_add_del(is_add=0,
-                                       table={'table_id': vrf_id_out})
+            self.vapi.ip_table_add_del(is_add=0, table={"table_id": vrf_id_in})
+            self.vapi.ip_table_add_del(is_add=0, table={"table_id": vrf_id_out})
 
     def test_dynamic_output_feature_vrf(self):
-        """ NAT44ED dynamic translation test: output-feature, VRF"""
+        """NAT44ED dynamic translation test: output-feature, VRF"""
 
         # other then default (0)
         new_vrf_id = 22
 
         self.nat_add_address(self.nat_addr)
         self.vapi.nat44_ed_add_del_output_interface(
-            sw_if_index=self.pg8.sw_if_index,
-            is_add=1)
+            sw_if_index=self.pg8.sw_if_index, is_add=1
+        )
         try:
             self.configure_ip4_interface(self.pg7, table_id=new_vrf_id)
             self.configure_ip4_interface(self.pg8, table_id=new_vrf_id)
 
             # in2out
-            tcpn = self.statistics['/nat44-ed/in2out/slowpath/tcp']
-            udpn = self.statistics['/nat44-ed/in2out/slowpath/udp']
-            icmpn = self.statistics['/nat44-ed/in2out/slowpath/icmp']
-            drops = self.statistics['/nat44-ed/in2out/slowpath/drops']
+            tcpn = self.statistics["/nat44-ed/in2out/slowpath/tcp"]
+            udpn = self.statistics["/nat44-ed/in2out/slowpath/udp"]
+            icmpn = self.statistics["/nat44-ed/in2out/slowpath/icmp"]
+            drops = self.statistics["/nat44-ed/in2out/slowpath/drops"]
 
             pkts = self.create_stream_in(self.pg7, self.pg8)
             self.pg7.add_stream(pkts)
@@ -3822,20 +4179,20 @@ class TestNAT44EDMW(TestNAT44ED):
             self.verify_capture_out(capture, ignore_port=True)
 
             if_idx = self.pg8.sw_if_index
-            cnt = self.statistics['/nat44-ed/in2out/slowpath/tcp']
+            cnt = self.statistics["/nat44-ed/in2out/slowpath/tcp"]
             self.assertEqual(cnt[:, if_idx].sum() - tcpn[:, if_idx].sum(), 2)
-            cnt = self.statistics['/nat44-ed/in2out/slowpath/udp']
+            cnt = self.statistics["/nat44-ed/in2out/slowpath/udp"]
             self.assertEqual(cnt[:, if_idx].sum() - udpn[:, if_idx].sum(), 1)
-            cnt = self.statistics['/nat44-ed/in2out/slowpath/icmp']
+            cnt = self.statistics["/nat44-ed/in2out/slowpath/icmp"]
             self.assertEqual(cnt[:, if_idx].sum() - icmpn[:, if_idx].sum(), 1)
-            cnt = self.statistics['/nat44-ed/in2out/slowpath/drops']
+            cnt = self.statistics["/nat44-ed/in2out/slowpath/drops"]
             self.assertEqual(cnt[:, if_idx].sum() - drops[:, if_idx].sum(), 0)
 
             # out2in
-            tcpn = self.statistics['/nat44-ed/out2in/fastpath/tcp']
-            udpn = self.statistics['/nat44-ed/out2in/fastpath/udp']
-            icmpn = self.statistics['/nat44-ed/out2in/fastpath/icmp']
-            drops = self.statistics['/nat44-ed/out2in/fastpath/drops']
+            tcpn = self.statistics["/nat44-ed/out2in/fastpath/tcp"]
+            udpn = self.statistics["/nat44-ed/out2in/fastpath/udp"]
+            icmpn = self.statistics["/nat44-ed/out2in/fastpath/icmp"]
+            drops = self.statistics["/nat44-ed/out2in/fastpath/drops"]
 
             pkts = self.create_stream_out(self.pg8)
             self.pg8.add_stream(pkts)
@@ -3845,48 +4202,56 @@ class TestNAT44EDMW(TestNAT44ED):
             self.verify_capture_in(capture, self.pg7)
 
             if_idx = self.pg8.sw_if_index
-            cnt = self.statistics['/nat44-ed/out2in/fastpath/tcp']
+            cnt = self.statistics["/nat44-ed/out2in/fastpath/tcp"]
             self.assertEqual(cnt[:, if_idx].sum() - tcpn[:, if_idx].sum(), 2)
-            cnt = self.statistics['/nat44-ed/out2in/fastpath/udp']
+            cnt = self.statistics["/nat44-ed/out2in/fastpath/udp"]
             self.assertEqual(cnt[:, if_idx].sum() - udpn[:, if_idx].sum(), 1)
-            cnt = self.statistics['/nat44-ed/out2in/fastpath/icmp']
+            cnt = self.statistics["/nat44-ed/out2in/fastpath/icmp"]
             self.assertEqual(cnt[:, if_idx].sum() - icmpn[:, if_idx].sum(), 1)
-            cnt = self.statistics['/nat44-ed/out2in/fastpath/drops']
+            cnt = self.statistics["/nat44-ed/out2in/fastpath/drops"]
             self.assertEqual(cnt[:, if_idx].sum() - drops[:, if_idx].sum(), 0)
 
-            sessions = self.statistics['/nat44-ed/total-sessions']
+            sessions = self.statistics["/nat44-ed/total-sessions"]
             self.assertEqual(sessions[:, 0].sum(), 3)
 
         finally:
             self.pg7.unconfig()
             self.pg8.unconfig()
 
-            self.vapi.ip_table_add_del(is_add=0,
-                                       table={'table_id': new_vrf_id})
+            self.vapi.ip_table_add_del(is_add=0, table={"table_id": new_vrf_id})
 
     def test_next_src_nat(self):
-        """ NAT44ED On way back forward packet to nat44-in2out node. """
+        """NAT44ED On way back forward packet to nat44-in2out node."""
 
-        twice_nat_addr = '10.0.1.3'
+        twice_nat_addr = "10.0.1.3"
         external_port = 80
         local_port = 8080
         post_twice_nat_port = 0
 
         self.vapi.nat44_forwarding_enable_disable(enable=1)
         self.nat_add_address(twice_nat_addr, twice_nat=1)
-        flags = (self.config_flags.NAT_IS_OUT2IN_ONLY |
-                 self.config_flags.NAT_IS_SELF_TWICE_NAT)
-        self.nat_add_static_mapping(self.pg6.remote_ip4, self.pg1.remote_ip4,
-                                    local_port, external_port,
-                                    proto=IP_PROTOS.tcp, vrf_id=1,
-                                    flags=flags)
+        flags = (
+            self.config_flags.NAT_IS_OUT2IN_ONLY
+            | self.config_flags.NAT_IS_SELF_TWICE_NAT
+        )
+        self.nat_add_static_mapping(
+            self.pg6.remote_ip4,
+            self.pg1.remote_ip4,
+            local_port,
+            external_port,
+            proto=IP_PROTOS.tcp,
+            vrf_id=1,
+            flags=flags,
+        )
         self.vapi.nat44_interface_add_del_feature(
-            sw_if_index=self.pg6.sw_if_index,
-            is_add=1)
+            sw_if_index=self.pg6.sw_if_index, is_add=1
+        )
 
-        p = (Ether(src=self.pg6.remote_mac, dst=self.pg6.local_mac) /
-             IP(src=self.pg6.remote_ip4, dst=self.pg1.remote_ip4) /
-             TCP(sport=12345, dport=external_port))
+        p = (
+            Ether(src=self.pg6.remote_mac, dst=self.pg6.local_mac)
+            / IP(src=self.pg6.remote_ip4, dst=self.pg1.remote_ip4)
+            / TCP(sport=12345, dport=external_port)
+        )
         self.pg6.add_stream(p)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
@@ -3905,9 +4270,11 @@ class TestNAT44EDMW(TestNAT44ED):
             self.logger.error(ppp("Unexpected or invalid packet:", p))
             raise
 
-        p = (Ether(src=self.pg6.remote_mac, dst=self.pg6.local_mac) /
-             IP(src=self.pg6.remote_ip4, dst=twice_nat_addr) /
-             TCP(sport=local_port, dport=post_twice_nat_port))
+        p = (
+            Ether(src=self.pg6.remote_mac, dst=self.pg6.local_mac)
+            / IP(src=self.pg6.remote_ip4, dst=twice_nat_addr)
+            / TCP(sport=local_port, dport=post_twice_nat_port)
+        )
         self.pg6.add_stream(p)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
@@ -3926,7 +4293,7 @@ class TestNAT44EDMW(TestNAT44ED):
             raise
 
     def test_one_armed_nat44_static(self):
-        """ NAT44ED One armed NAT and 1:1 NAPT asymmetrical rule """
+        """NAT44ED One armed NAT and 1:1 NAPT asymmetrical rule"""
 
         remote_host = self.pg4.remote_hosts[0]
         local_host = self.pg4.remote_hosts[1]
@@ -3936,23 +4303,31 @@ class TestNAT44EDMW(TestNAT44ED):
 
         self.vapi.nat44_forwarding_enable_disable(enable=1)
         self.nat_add_address(self.nat_addr, twice_nat=1)
-        flags = (self.config_flags.NAT_IS_OUT2IN_ONLY |
-                 self.config_flags.NAT_IS_TWICE_NAT)
-        self.nat_add_static_mapping(local_host.ip4, self.nat_addr,
-                                    local_port, external_port,
-                                    proto=IP_PROTOS.tcp, flags=flags)
+        flags = (
+            self.config_flags.NAT_IS_OUT2IN_ONLY | self.config_flags.NAT_IS_TWICE_NAT
+        )
+        self.nat_add_static_mapping(
+            local_host.ip4,
+            self.nat_addr,
+            local_port,
+            external_port,
+            proto=IP_PROTOS.tcp,
+            flags=flags,
+        )
         flags = self.config_flags.NAT_IS_INSIDE
         self.vapi.nat44_interface_add_del_feature(
-            sw_if_index=self.pg4.sw_if_index,
-            is_add=1)
+            sw_if_index=self.pg4.sw_if_index, is_add=1
+        )
         self.vapi.nat44_interface_add_del_feature(
-            sw_if_index=self.pg4.sw_if_index,
-            flags=flags, is_add=1)
+            sw_if_index=self.pg4.sw_if_index, flags=flags, is_add=1
+        )
 
         # from client to service
-        p = (Ether(src=self.pg4.remote_mac, dst=self.pg4.local_mac) /
-             IP(src=remote_host.ip4, dst=self.nat_addr) /
-             TCP(sport=12345, dport=external_port))
+        p = (
+            Ether(src=self.pg4.remote_mac, dst=self.pg4.local_mac)
+            / IP(src=remote_host.ip4, dst=self.nat_addr)
+            / TCP(sport=12345, dport=external_port)
+        )
         self.pg4.add_stream(p)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
@@ -3972,9 +4347,11 @@ class TestNAT44EDMW(TestNAT44ED):
             raise
 
         # from service back to client
-        p = (Ether(src=self.pg4.remote_mac, dst=self.pg4.local_mac) /
-             IP(src=local_host.ip4, dst=self.nat_addr) /
-             TCP(sport=local_port, dport=eh_port_in))
+        p = (
+            Ether(src=self.pg4.remote_mac, dst=self.pg4.local_mac)
+            / IP(src=local_host.ip4, dst=self.nat_addr)
+            / TCP(sport=local_port, dport=eh_port_in)
+        )
         self.pg4.add_stream(p)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
@@ -3993,7 +4370,7 @@ class TestNAT44EDMW(TestNAT44ED):
             raise
 
     def test_icmp_error_fwd_outbound(self):
-        """ NAT44ED ICMP error outbound with forwarding enabled """
+        """NAT44ED ICMP error outbound with forwarding enabled"""
 
         # Ensure that an outbound ICMP error message is properly associated
         # with the inbound forward bypass session it is related to.
@@ -4005,9 +4382,12 @@ class TestNAT44EDMW(TestNAT44ED):
 
         # enable forwarding and initiate connection out2in
         self.vapi.nat44_forwarding_enable_disable(enable=1)
-        p1 = (Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac) /
-              IP(src=self.pg1.remote_ip4, dst=self.pg0.remote_ip4) /
-              UDP(sport=21, dport=20) / payload)
+        p1 = (
+            Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac)
+            / IP(src=self.pg1.remote_ip4, dst=self.pg0.remote_ip4)
+            / UDP(sport=21, dport=20)
+            / payload
+        )
 
         self.pg1.add_stream(p1)
         self.pg_enable_capture(self.pg_interfaces)
@@ -4021,10 +4401,12 @@ class TestNAT44EDMW(TestNAT44ED):
         # session dumps for a user will only look on the worker that the
         # user is supposed to be mapped to in2out. The forward bypass session
         # is not necessarily created on that worker.
-        p2 = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
-              IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
-              ICMP(type='dest-unreach', code='port-unreachable') /
-              capture[IP:])
+        p2 = (
+            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+            / IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4)
+            / ICMP(type="dest-unreach", code="port-unreachable")
+            / capture[IP:]
+        )
 
         self.pg0.add_stream(p2)
         self.pg_enable_capture(self.pg_interfaces)
@@ -4038,11 +4420,11 @@ class TestNAT44EDMW(TestNAT44ED):
         self.logger.info(ppp("capture packet:", capture))
 
     def test_tcp_session_open_retransmit1(self):
-        """ NAT44ED Open TCP session with SYN,ACK retransmit 1
+        """NAT44ED Open TCP session with SYN,ACK retransmit 1
 
-            The client does not receive the [SYN,ACK] or the
-            ACK from the client is lost. Therefore, the [SYN, ACK]
-            is retransmitted by the server.
+        The client does not receive the [SYN,ACK] or the
+        ACK from the client is lost. Therefore, the [SYN, ACK]
+        is retransmitted by the server.
         """
 
         in_port = self.tcp_port_in
@@ -4053,50 +4435,61 @@ class TestNAT44EDMW(TestNAT44ED):
         self.nat_add_inside_interface(self.pg0)
         self.nat_add_outside_interface(self.pg1)
 
-        self.vapi.nat_set_timeouts(udp=300, tcp_established=7440,
-                                   tcp_transitory=5, icmp=60)
+        self.vapi.nat_set_timeouts(
+            udp=300, tcp_established=7440, tcp_transitory=5, icmp=60
+        )
         # SYN packet in->out
-        p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
-             IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
-             TCP(sport=in_port, dport=ext_port, flags="S"))
+        p = (
+            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+            / IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4)
+            / TCP(sport=in_port, dport=ext_port, flags="S")
+        )
         p = self.send_and_expect(self.pg0, p, self.pg1)[0]
         out_port = p[TCP].sport
 
         # SYN + ACK packet out->in
-        p = (Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac) /
-             IP(src=self.pg1.remote_ip4, dst=self.nat_addr) /
-             TCP(sport=ext_port, dport=out_port, flags="SA"))
+        p = (
+            Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac)
+            / IP(src=self.pg1.remote_ip4, dst=self.nat_addr)
+            / TCP(sport=ext_port, dport=out_port, flags="SA")
+        )
         self.send_and_expect(self.pg1, p, self.pg0)
 
         # ACK in->out does not arrive
 
         # resent SYN + ACK packet out->in
-        p = (Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac) /
-             IP(src=self.pg1.remote_ip4, dst=self.nat_addr) /
-             TCP(sport=ext_port, dport=out_port, flags="SA"))
+        p = (
+            Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac)
+            / IP(src=self.pg1.remote_ip4, dst=self.nat_addr)
+            / TCP(sport=ext_port, dport=out_port, flags="SA")
+        )
         self.send_and_expect(self.pg1, p, self.pg0)
 
         # ACK packet in->out
-        p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
-             IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
-             TCP(sport=in_port, dport=ext_port, flags="A"))
+        p = (
+            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+            / IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4)
+            / TCP(sport=in_port, dport=ext_port, flags="A")
+        )
         self.send_and_expect(self.pg0, p, self.pg1)
 
         # Verify that the data can be transmitted after the transitory time
         self.virtual_sleep(6)
 
-        p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
-             IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
-             TCP(sport=in_port, dport=ext_port, flags="PA") /
-             Raw(payload))
+        p = (
+            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+            / IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4)
+            / TCP(sport=in_port, dport=ext_port, flags="PA")
+            / Raw(payload)
+        )
         self.send_and_expect(self.pg0, p, self.pg1)
 
     def test_tcp_session_open_retransmit2(self):
-        """ NAT44ED Open TCP session with SYN,ACK retransmit 2
+        """NAT44ED Open TCP session with SYN,ACK retransmit 2
 
-            The ACK is lost to the server after the TCP session is opened.
-            Data is sent by the client, then the [SYN,ACK] is
-            retransmitted by the server.
+        The ACK is lost to the server after the TCP session is opened.
+        Data is sent by the client, then the [SYN,ACK] is
+        retransmitted by the server.
         """
 
         in_port = self.tcp_port_in
@@ -4107,68 +4500,87 @@ class TestNAT44EDMW(TestNAT44ED):
         self.nat_add_inside_interface(self.pg0)
         self.nat_add_outside_interface(self.pg1)
 
-        self.vapi.nat_set_timeouts(udp=300, tcp_established=7440,
-                                   tcp_transitory=5, icmp=60)
+        self.vapi.nat_set_timeouts(
+            udp=300, tcp_established=7440, tcp_transitory=5, icmp=60
+        )
         # SYN packet in->out
-        p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
-             IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
-             TCP(sport=in_port, dport=ext_port, flags="S"))
+        p = (
+            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+            / IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4)
+            / TCP(sport=in_port, dport=ext_port, flags="S")
+        )
         p = self.send_and_expect(self.pg0, p, self.pg1)[0]
         out_port = p[TCP].sport
 
         # SYN + ACK packet out->in
-        p = (Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac) /
-             IP(src=self.pg1.remote_ip4, dst=self.nat_addr) /
-             TCP(sport=ext_port, dport=out_port, flags="SA"))
+        p = (
+            Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac)
+            / IP(src=self.pg1.remote_ip4, dst=self.nat_addr)
+            / TCP(sport=ext_port, dport=out_port, flags="SA")
+        )
         self.send_and_expect(self.pg1, p, self.pg0)
 
         # ACK packet in->out -- not received by the server
-        p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
-             IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
-             TCP(sport=in_port, dport=ext_port, flags="A"))
+        p = (
+            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+            / IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4)
+            / TCP(sport=in_port, dport=ext_port, flags="A")
+        )
         self.send_and_expect(self.pg0, p, self.pg1)
 
         # PUSH + ACK packet in->out
-        p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
-             IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
-             TCP(sport=in_port, dport=ext_port, flags="PA") /
-             Raw(payload))
+        p = (
+            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+            / IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4)
+            / TCP(sport=in_port, dport=ext_port, flags="PA")
+            / Raw(payload)
+        )
         self.send_and_expect(self.pg0, p, self.pg1)
 
         # resent SYN + ACK packet out->in
-        p = (Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac) /
-             IP(src=self.pg1.remote_ip4, dst=self.nat_addr) /
-             TCP(sport=ext_port, dport=out_port, flags="SA"))
+        p = (
+            Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac)
+            / IP(src=self.pg1.remote_ip4, dst=self.nat_addr)
+            / TCP(sport=ext_port, dport=out_port, flags="SA")
+        )
         self.send_and_expect(self.pg1, p, self.pg0)
 
         # resent ACK packet in->out
-        p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
-             IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
-             TCP(sport=in_port, dport=ext_port, flags="A"))
+        p = (
+            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+            / IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4)
+            / TCP(sport=in_port, dport=ext_port, flags="A")
+        )
         self.send_and_expect(self.pg0, p, self.pg1)
 
         # resent PUSH + ACK packet in->out
-        p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
-             IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
-             TCP(sport=in_port, dport=ext_port, flags="PA") /
-             Raw(payload))
+        p = (
+            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+            / IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4)
+            / TCP(sport=in_port, dport=ext_port, flags="PA")
+            / Raw(payload)
+        )
         self.send_and_expect(self.pg0, p, self.pg1)
 
         # ACK packet out->in
-        p = (Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac) /
-             IP(src=self.pg1.remote_ip4, dst=self.nat_addr) /
-             TCP(sport=ext_port, dport=out_port, flags="A"))
+        p = (
+            Ether(src=self.pg1.remote_mac, dst=self.pg1.local_mac)
+            / IP(src=self.pg1.remote_ip4, dst=self.nat_addr)
+            / TCP(sport=ext_port, dport=out_port, flags="A")
+        )
         self.send_and_expect(self.pg1, p, self.pg0)
 
         # Verify that the data can be transmitted after the transitory time
         self.virtual_sleep(6)
 
-        p = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
-             IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4) /
-             TCP(sport=in_port, dport=ext_port, flags="PA") /
-             Raw(payload))
+        p = (
+            Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac)
+            / IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4)
+            / TCP(sport=in_port, dport=ext_port, flags="PA")
+            / Raw(payload)
+        )
         self.send_and_expect(self.pg0, p, self.pg1)
 
 
-if __name__ == '__main__':
+if __name__ == "__main__":
     unittest.main(testRunner=VppTestRunner)