nat: refactor & MW support for NAT tests

Split ED and EI nat44 test cases. Added multi worker
support for ED test cases.

Type: refactor

Change-Id: Ibcc2f62b94cacff69ed35c5d914b55f9fdbcf882
Signed-off-by: Filip Varga <fivarga@cisco.com>

1 files changed, 3532 insertions, 0 deletions

diff --git a/src/plugins/nat/test/test_nat44_ed.py b/src/plugins/nat/test/test_nat44_ed.py
new file mode 100644
index 00000000000..0f4a7371048
--- /dev/null
+++ b/src/plugins/nat/test/test_nat44_ed.py
@@ -0,0 +1,3532 @@
+#!/usr/bin/env python3
+
+import unittest
+from io import BytesIO
+from random import randint
+
+import scapy.compat
+from framework import VppTestCase, VppTestRunner
+from scapy.data import IP_PROTOS
+from scapy.layers.inet import IP, TCP, UDP, ICMP, GRE
+from scapy.layers.inet import IPerror, TCPerror
+from scapy.layers.l2 import Ether
+from scapy.packet import Raw
+from syslog_rfc5424_parser import SyslogMessage, ParseError
+from syslog_rfc5424_parser.constants import SyslogSeverity
+from util import ppp, ip4_range
+from vpp_acl import AclRule, VppAcl, VppAclInterface
+from vpp_ip_route import VppIpRoute, VppRoutePath
+from vpp_papi import VppEnum
+
+
+class NAT44EDTestCase(VppTestCase):
+
+    nat_addr = '10.0.0.3'
+
+    tcp_port_in = 6303
+    tcp_port_out = 6303
+
+    udp_port_in = 6304
+    udp_port_out = 6304
+
+    icmp_id_in = 6305
+    icmp_id_out = 6305
+
+    tcp_external_port = 80
+
+    max_sessions = 100
+
+    def setUp(self):
+        super(NAT44EDTestCase, self).setUp()
+        self.plugin_enable()
+
+    def tearDown(self):
+        super(NAT44EDTestCase, self).tearDown()
+        if not self.vpp_dead:
+            self.plugin_disable()
+
+    def plugin_enable(self):
+        self.vapi.nat44_plugin_enable_disable(
+            flags=self.nat44_config_flags.NAT44_IS_ENDPOINT_DEPENDENT,
+            sessions=self.max_sessions, enable=1)
+
+    def plugin_disable(self):
+        self.vapi.nat44_plugin_enable_disable(enable=0)
+
+    @property
+    def config_flags(self):
+        return VppEnum.vl_api_nat_config_flags_t
+
+    @property
+    def nat44_config_flags(self):
+        return VppEnum.vl_api_nat44_config_flags_t
+
+    @property
+    def syslog_severity(self):
+        return VppEnum.vl_api_syslog_severity_t
+
+    @property
+    def server_addr(self):
+        return self.pg1.remote_hosts[0].ip4
+
+    @staticmethod
+    def random_port():
+        return randint(1025, 65535)
+
+    @staticmethod
+    def proto2layer(proto):
+        if proto == IP_PROTOS.tcp:
+            return TCP
+        elif proto == IP_PROTOS.udp:
+            return UDP
+        elif proto == IP_PROTOS.icmp:
+            return ICMP
+        else:
+            raise Exception("Unsupported protocol")
+
+    @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})
+        i.set_table_ip4(table_id)
+
+    @classmethod
+    def configure_ip4_interface(cls, i, hosts=0, table_id=None):
+        if table_id:
+            cls.create_and_add_ip4_table(i, table_id)
+
+        i.admin_up()
+        i.unconfig_ip4()
+        i.config_ip4()
+        i.resolve_arp()
+
+        if hosts:
+            i.generate_remote_hosts(hosts)
+            i.configure_ipv4_neighbors()
+
+    @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)
+
+    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)
+
+    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)
+
+    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)
+
+    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
+
+        self.vapi.nat44_add_del_static_mapping(
+            is_add=is_add,
+            local_ip_address=local_ip,
+            external_ip_address=external_ip,
+            external_sw_if_index=external_sw_if_index,
+            local_port=local_port,
+            external_port=external_port,
+            vrf_id=vrf_id, protocol=proto,
+            flags=flags,
+            tag=tag)
+
+    @classmethod
+    def setUpClass(cls):
+        super(NAT44EDTestCase, cls).setUpClass()
+        cls.vapi.cli("set log class nat level debug")
+
+        cls.create_pg_interfaces(range(12))
+        cls.interfaces = list(cls.pg_interfaces[:4])
+
+        cls.create_and_add_ip4_table(cls.pg2, 10)
+
+        for i in cls.interfaces:
+            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})
+
+        # 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")
+        cls.pg4.admin_up()
+        cls.pg4.resolve_arp()
+        cls.pg4._remote_hosts[1]._ip4 = cls.pg4._remote_hosts[0]._ip4
+        cls.pg4.resolve_arp()
+
+        # test specific interface (pg5)
+        cls.pg5._local_ip4 = "10.1.1.1"
+        cls.pg5._remote_hosts[0]._ip4 = "10.1.1.2"
+        cls.pg5.set_table_ip4(1)
+        cls.pg5.config_ip4()
+        cls.pg5.admin_up()
+        cls.pg5.resolve_arp()
+
+        # test specific interface (pg6)
+        cls.pg6._local_ip4 = "10.1.2.1"
+        cls.pg6._remote_hosts[0]._ip4 = "10.1.2.2"
+        cls.pg6.set_table_ip4(1)
+        cls.pg6.config_ip4()
+        cls.pg6.admin_up()
+        cls.pg6.resolve_arp()
+
+        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))
+
+        for r in rl:
+            r.add_vpp_config()
+
+    def get_err_counter(self, path):
+        return self.statistics.get_err_counter(path)
+
+    def get_stats_counter(self, path, worker=0):
+        return self.statistics.get_counter(path)[worker]
+
+    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:
+            data = b"A" * 4 + b"B" * 16 + b"C" * 3
+        else:
+            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)
+        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)
+        if proto != IP_PROTOS.icmp:
+            if not ignore_port:
+                self.assertNotEqual(p[layer].sport, host_in_port)
+            self.assertEqual(p[layer].dport, server_in_port)
+        else:
+            if not ignore_port:
+                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):
+        layer = self.proto2layer(proto)
+
+        if proto == IP_PROTOS.tcp:
+            data = b"A" * 4 + b"B" * 16 + b"C" * 3
+        else:
+            data = b"A" * 16 + b"B" * 16 + b"C" * 3
+        self.port_in = self.random_port()
+
+        for i in range(2):
+            # in2out
+            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)
+            else:
+                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)
+                    if not ignore_port:
+                        self.assertNotEqual(p[layer].sport, self.port_in)
+                else:
+                    self.assertEqual(p[layer].sport, self.port_in)
+            else:
+                if not ignore_port:
+                    if not dont_translate:
+                        self.assertNotEqual(p[layer].id, self.port_in)
+                    else:
+                        self.assertEqual(p[layer].id, self.port_in)
+            self.assertEqual(data, p[Raw].load)
+
+            # out2in
+            if not dont_translate:
+                dst_addr = self.nat_addr
+            else:
+                dst_addr = self.pg0.remote_ip4
+            if proto != IP_PROTOS.icmp:
+                sport = 20
+                dport = p[layer].sport
+            else:
+                sport = p[layer].id
+                dport = 0
+            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.pg_start()
+            frags = self.pg0.get_capture(len(pkts))
+            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)
+            else:
+                self.assertEqual(p[layer].id, self.port_in)
+            self.assertEqual(data, p[Raw].load)
+
+    def reass_frags_and_verify(self, frags, src, dst):
+        buffer = BytesIO()
+        for p in frags:
+            self.assertEqual(p[IP].src, src)
+            self.assertEqual(p[IP].dst, dst)
+            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)
+        if ip.proto == IP_PROTOS.tcp:
+            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:]))
+        elif ip.proto == IP_PROTOS.icmp:
+            p = (ip / ICMP(buffer.getvalue()))
+        return p
+
+    def frag_in_order(self, proto=IP_PROTOS.tcp, dont_translate=False,
+                      ignore_port=False):
+        layer = self.proto2layer(proto)
+
+        if proto == IP_PROTOS.tcp:
+            data = b"A" * 4 + b"B" * 16 + b"C" * 3
+        else:
+            data = b"A" * 16 + b"B" * 16 + b"C" * 3
+        self.port_in = self.random_port()
+
+        # in2out
+        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)
+        else:
+            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)
+                if not ignore_port:
+                    self.assertNotEqual(p[layer].sport, self.port_in)
+            else:
+                self.assertEqual(p[layer].sport, self.port_in)
+        else:
+            if not ignore_port:
+                if not dont_translate:
+                    self.assertNotEqual(p[layer].id, self.port_in)
+                else:
+                    self.assertEqual(p[layer].id, self.port_in)
+        self.assertEqual(data, p[Raw].load)
+
+        # out2in
+        if not dont_translate:
+            dst_addr = self.nat_addr
+        else:
+            dst_addr = self.pg0.remote_ip4
+        if proto != IP_PROTOS.icmp:
+            sport = 20
+            dport = p[layer].sport
+        else:
+            sport = p[layer].id
+            dport = 0
+        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)
+        if proto != IP_PROTOS.icmp:
+            self.assertEqual(p[layer].sport, 20)
+            self.assertEqual(p[layer].dport, self.port_in)
+        else:
+            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):
+        if nat_ip is None:
+            nat_ip = self.nat_addr
+        for packet in capture:
+            try:
+                self.assert_packet_checksums_valid(packet)
+                self.assertEqual(packet[IP].src, nat_ip)
+                if dst_ip is not None:
+                    self.assertEqual(packet[IP].dst, dst_ip)
+                if packet.haslayer(TCP):
+                    if not ignore_port:
+                        if same_port:
+                            self.assertEqual(
+                                packet[TCP].sport, self.tcp_port_in)
+                        else:
+                            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)
+                        else:
+                            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)
+                        else:
+                            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))
+                raise
+
+    def verify_capture_in(self, capture, in_if):
+        for packet in capture:
+            try:
+                self.assert_packet_checksums_valid(packet)
+                self.assertEqual(packet[IP].dst, in_if.remote_ip4)
+                if packet.haslayer(TCP):
+                    self.assertEqual(packet[TCP].dport, self.tcp_port_in)
+                elif packet.haslayer(UDP):
+                    self.assertEqual(packet[UDP].dport, self.udp_port_in)
+                else:
+                    self.assertEqual(packet[ICMP].id, self.icmp_id_in)
+            except:
+                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):
+        if dst_ip is None:
+            dst_ip = out_if.remote_ip4
+
+        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))
+        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))
+        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'))
+        pkts.append(p)
+
+        return pkts
+
+    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:
+            tcp_port = self.tcp_port_out
+            udp_port = self.udp_port_out
+            icmp_id = self.icmp_id_out
+        else:
+            tcp_port = self.tcp_port_in
+            udp_port = self.udp_port_in
+            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))
+        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))
+        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'))
+        pkts.append(p)
+
+        return pkts
+
+    def create_tcp_stream(self, in_if, out_if, count):
+        pkts = []
+        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))
+            pkts.append(p)
+
+        return pkts
+
+    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 = p.__class__(scapy.compat.raw(p))
+            chksum = p[TCP].chksum
+            proto_header = TCP(sport=sport, dport=dport, chksum=chksum)
+        elif proto == IP_PROTOS.udp:
+            proto_header = UDP(sport=sport, dport=dport)
+        elif proto == IP_PROTOS.icmp:
+            if not echo_reply:
+                proto_header = ICMP(id=sport, type='echo-request')
+            else:
+                proto_header = ICMP(id=sport, type='echo-reply')
+        else:
+            raise Exception("Unsupported protocol")
+        id = self.random_port()
+        pkts = []
+        if proto == IP_PROTOS.tcp:
+            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)
+        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)
+        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)
+        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):
+
+        layer = self.proto2layer(proto)
+
+        if proto == IP_PROTOS.tcp:
+            data = b"A" * 4 + b"B" * 16 + b"C" * 3
+        else:
+            data = b"A" * 16 + b"B" * 16 + b"C" * 3
+        port_in = self.random_port()
+
+        for i in range(2):
+            # out2in
+            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)
+            if proto != IP_PROTOS.icmp:
+                self.assertEqual(p[layer].sport, port_in)
+                self.assertEqual(p[layer].dport, in_port)
+            else:
+                self.assertEqual(p[layer].id, port_in)
+            self.assertEqual(data, p[Raw].load)
+
+            # in2out
+            if proto != IP_PROTOS.icmp:
+                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)
+            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)
+            if proto != IP_PROTOS.icmp:
+                self.assertEqual(p[layer].sport, out_port)
+                self.assertEqual(p[layer].dport, port_in)
+            else:
+                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):
+
+        layer = self.proto2layer(proto)
+
+        if proto == IP_PROTOS.tcp:
+            data = b"A" * 4 + b"B" * 16 + b"C" * 3
+        else:
+            data = b"A" * 16 + b"B" * 16 + b"C" * 3
+        port_in = self.random_port()
+
+        for i in range(2):
+            # out2in
+            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)
+            if proto != IP_PROTOS.icmp:
+                self.assertEqual(p[layer].dport, in_port)
+                self.assertEqual(p[layer].sport, port_in)
+                self.assertEqual(p[layer].dport, in_port)
+            else:
+                self.assertEqual(p[layer].id, port_in)
+            self.assertEqual(data, p[Raw].load)
+
+            # in2out
+            if proto != IP_PROTOS.icmp:
+                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.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)
+            if proto != IP_PROTOS.icmp:
+                self.assertEqual(p[layer].sport, out_port)
+                self.assertEqual(p[layer].dport, port_in)
+            else:
+                self.assertEqual(p[layer].id, port_in)
+            self.assertEqual(data, p[Raw].load)
+
+    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"))
+        in_if.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = out_if.get_capture(1)
+        p = capture[0]
+        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"))
+        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"))
+        in_if.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        out_if.get_capture(1)
+
+        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'
+
+        port_in = 8080
+        if lb:
+            if not same_pg:
+                port_in1 = port_in
+                port_in2 = port_in
+            else:
+                port_in1 = port_in + 1
+                port_in2 = port_in + 2
+
+        port_out = 80
+        eh_port_out = 4567
+
+        server1 = self.pg0.remote_hosts[0]
+        server2 = self.pg0.remote_hosts[1]
+        if lb and same_pg:
+            server2 = server1
+        if not lb:
+            server = server1
+
+        pg0 = self.pg0
+        if same_pg:
+            pg1 = self.pg0
+        else:
+            pg1 = self.pg1
+
+        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)
+
+        flags = 0
+        if self_twice_nat:
+            flags |= self.config_flags.NAT_IS_SELF_TWICE_NAT
+        else:
+            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)
+        else:
+            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.nat_add_inside_interface(pg0)
+        self.nat_add_outside_interface(pg1)
+
+        if same_pg:
+            if not lb:
+                client = server
+            else:
+                assert client_id is not None
+                if client_id == 1:
+                    client = self.pg0.remote_hosts[0]
+                elif client_id == 2:
+                    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))
+        pg1.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = pg0.get_capture(1)
+        p = capture[0]
+        try:
+            ip = p[IP]
+            tcp = p[TCP]
+            if lb:
+                if ip.dst == server1.ip4:
+                    server = server1
+                    port_in = port_in1
+                else:
+                    server = server2
+                    port_in = port_in2
+            self.assertEqual(ip.dst, server.ip4)
+            if lb and same_pg:
+                self.assertIn(tcp.dport, [port_in1, port_in2])
+            else:
+                self.assertEqual(tcp.dport, port_in)
+            if eh_translate:
+                self.assertEqual(ip.src, twice_nat_addr)
+                self.assertNotEqual(tcp.sport, eh_port_out)
+            else:
+                self.assertEqual(ip.src, client.ip4)
+                self.assertEqual(tcp.sport, eh_port_out)
+            eh_addr_in = ip.src
+            eh_port_in = tcp.sport
+            saved_port_in = tcp.dport
+            self.assert_packet_checksums_valid(p)
+        except:
+            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))
+        pg0.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = pg1.get_capture(1)
+        p = capture[0]
+        try:
+            ip = p[IP]
+            tcp = p[TCP]
+            self.assertEqual(ip.dst, client.ip4)
+            self.assertEqual(ip.src, self.nat_addr)
+            self.assertEqual(tcp.dport, eh_port_out)
+            self.assertEqual(tcp.sport, port_out)
+            self.assert_packet_checksums_valid(p)
+        except:
+            self.logger.error(ppp("Unexpected or invalid packet:", p))
+            raise
+
+        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.logger.info(self.vapi.cli("show nat44 sessions detail"))
+            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),
+                ext_host_address=sessions[0].ext_host_nat_address,
+                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, is_add=True, is_ip6=False):
+        message = data.decode('utf-8')
+        try:
+            message = SyslogMessage.parse(message)
+        except ParseError as e:
+            self.logger.error(e)
+            raise
+        else:
+            self.assertEqual(message.severity, SyslogSeverity.info)
+            self.assertEqual(message.appname, 'NAT')
+            self.assertEqual(message.msgid, 'SADD' if is_add else 'SDEL')
+            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)
+            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)
+
+
+class TestNAT44ED(NAT44EDTestCase):
+    """ NAT44ED Test Case """
+
+    def test_users_dump(self):
+        """ NAT44ED API test - nat44_user_dump """
+
+        self.nat_add_address(self.nat_addr)
+        self.nat_add_inside_interface(self.pg0)
+        self.nat_add_outside_interface(self.pg1)
+
+        self.vapi.nat44_forwarding_enable_disable(enable=1)
+
+        local_ip = self.pg0.remote_ip4
+        external_ip = self.nat_addr
+        self.nat_add_static_mapping(local_ip, external_ip)
+
+        users = self.vapi.nat44_user_dump()
+        self.assertEqual(len(users), 0)
+
+        # in2out - static mapping match
+
+        pkts = self.create_stream_out(self.pg1)
+        self.pg1.add_stream(pkts)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg0.get_capture(len(pkts))
+        self.verify_capture_in(capture, self.pg0)
+
+        pkts = self.create_stream_in(self.pg0, self.pg1)
+        self.pg0.add_stream(pkts)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg1.get_capture(len(pkts))
+        self.verify_capture_out(capture, same_port=True)
+
+        users = self.vapi.nat44_user_dump()
+        self.assertEqual(len(users), 1)
+        static_user = users[0]
+        self.assertEqual(static_user.nstaticsessions, 3)
+        self.assertEqual(static_user.nsessions, 0)
+
+        # in2out - no static mapping match (forwarding test)
+
+        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)
+            self.pg1.add_stream(pkts)
+            self.pg_enable_capture(self.pg_interfaces)
+            self.pg_start()
+            capture = self.pg0.get_capture(len(pkts))
+            self.verify_capture_in(capture, self.pg0)
+
+            pkts = self.create_stream_in(self.pg0, self.pg1)
+            self.pg0.add_stream(pkts)
+            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)
+        finally:
+            self.pg0.remote_hosts[0] = host0
+
+        users = self.vapi.nat44_user_dump()
+        self.assertEqual(len(users), 2)
+        if str(users[0].ip_address) == self.pg0.remote_hosts[0].ip4:
+            non_static_user = users[1]
+            static_user = users[0]
+        else:
+            non_static_user = users[0]
+            static_user = users[1]
+        self.assertEqual(static_user.nstaticsessions, 3)
+        self.assertEqual(static_user.nsessions, 0)
+        self.assertEqual(non_static_user.nstaticsessions, 0)
+        self.assertEqual(non_static_user.nsessions, 3)
+
+        users = self.vapi.nat44_user_dump()
+        self.assertEqual(len(users), 2)
+        if str(users[0].ip_address) == self.pg0.remote_hosts[0].ip4:
+            non_static_user = users[1]
+            static_user = users[0]
+        else:
+            non_static_user = users[0]
+            static_user = users[1]
+        self.assertEqual(static_user.nstaticsessions, 3)
+        self.assertEqual(static_user.nsessions, 0)
+        self.assertEqual(non_static_user.nstaticsessions, 0)
+        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 """
+        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 """
+
+        self.nat_add_inside_interface(self.pg0)
+        self.nat_add_outside_interface(self.pg1)
+        self.vapi.nat44_forwarding_enable_disable(enable=1)
+
+        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)
+
+        try:
+            # in2out - static mapping match
+
+            pkts = self.create_stream_out(self.pg1)
+            self.pg1.add_stream(pkts)
+            self.pg_enable_capture(self.pg_interfaces)
+            self.pg_start()
+            capture = self.pg0.get_capture(len(pkts))
+            self.verify_capture_in(capture, self.pg0)
+
+            pkts = self.create_stream_in(self.pg0, self.pg1)
+            self.pg0.add_stream(pkts)
+            self.pg_enable_capture(self.pg_interfaces)
+            self.pg_start()
+            capture = self.pg1.get_capture(len(pkts))
+            self.verify_capture_out(capture, same_port=True)
+
+            # in2out - no static mapping match
+
+            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)
+                self.pg1.add_stream(pkts)
+                self.pg_enable_capture(self.pg_interfaces)
+                self.pg_start()
+                capture = self.pg0.get_capture(len(pkts))
+                self.verify_capture_in(capture, self.pg0)
+
+                pkts = self.create_stream_in(self.pg0, self.pg1)
+                self.pg0.add_stream(pkts)
+                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)
+            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.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),
+                ext_host_address=sessions[0].ext_host_address,
+                ext_host_port=sessions[0].ext_host_port)
+            sessions = self.vapi.nat44_user_session_dump(user.ip4, 0)
+            self.assertEqual(len(sessions), 2)
+
+        finally:
+            self.vapi.nat44_forwarding_enable_disable(enable=0)
+            flags = self.config_flags.NAT_IS_ADDR_ONLY
+            self.vapi.nat44_add_del_static_mapping(
+                is_add=0,
+                local_ip_address=real_ip,
+                external_ip_address=alias_ip,
+                external_sw_if_index=0xFFFFFFFF,
+                flags=flags)
+
+    def test_output_feature_and_service2(self):
+        """ 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_interface_add_del_output_feature(
+            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)
+        self.pg0.add_stream(pkts)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg1.get_capture(len(pkts))
+        self.verify_capture_out(capture, ignore_port=True)
+
+        pkts = self.create_stream_out(self.pg1)
+        self.pg1.add_stream(pkts)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg0.get_capture(len(pkts))
+        self.verify_capture_in(capture, self.pg0)
+
+        # session initiated from remote host - do not translate
+        tcp_port_in = self.tcp_port_in
+        udp_port_in = self.udp_port_in
+        icmp_id_in = self.icmp_id_in
+
+        self.tcp_port_in = 60303
+        self.udp_port_in = 60304
+        self.icmp_id_in = 60305
+
+        try:
+            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()
+            capture = self.pg0.get_capture(len(pkts))
+            self.verify_capture_in(capture, self.pg0)
+
+            pkts = self.create_stream_in(self.pg0, self.pg1)
+            self.pg0.add_stream(pkts)
+            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)
+        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 """
+        self.twice_nat_common()
+
+    def test_self_twice_nat_positive(self):
+        """ 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)
+
+    def test_twice_nat_lb(self):
+        """ NAT44ED Twice NAT local service load balancing """
+        self.twice_nat_common(lb=True)
+
+    def test_output_feature(self):
+        """ 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_interface_add_del_output_feature(
+            sw_if_index=self.pg1.sw_if_index, is_add=1)
+
+        # in2out
+        pkts = self.create_stream_in(self.pg0, self.pg1)
+        self.pg0.add_stream(pkts)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg1.get_capture(len(pkts))
+        self.verify_capture_out(capture, ignore_port=True)
+
+        # out2in
+        pkts = self.create_stream_out(self.pg1)
+        self.pg1.add_stream(pkts)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg0.get_capture(len(pkts))
+        self.verify_capture_in(capture, self.pg0)
+
+    def test_static_with_port_out2(self):
+        """ 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_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))
+        self.pg1.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg0.get_capture(1)
+        p = capture[0]
+        try:
+            ip = p[IP]
+            tcp = p[TCP]
+            self.assertEqual(ip.dst, self.pg0.remote_ip4)
+            self.assertEqual(tcp.dport, local_port)
+            self.assert_packet_checksums_valid(p)
+        except:
+            self.logger.error(ppp("Unexpected or invalid packet:", p))
+            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])
+        self.pg0.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg1.get_capture(1)
+        p = capture[0]
+        try:
+            self.assertEqual(p[IP].src, self.nat_addr)
+            inner = p[IPerror]
+            self.assertEqual(inner.dst, self.nat_addr)
+            self.assertEqual(inner[TCPerror].dport, external_port)
+        except:
+            self.logger.error(ppp("Unexpected or invalid packet:", p))
+            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))
+        self.pg0.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg1.get_capture(1)
+        p = capture[0]
+        try:
+            ip = p[IP]
+            tcp = p[TCP]
+            self.assertEqual(ip.src, self.nat_addr)
+            self.assertEqual(tcp.sport, external_port)
+            self.assert_packet_checksums_valid(p)
+        except:
+            self.logger.error(ppp("Unexpected or invalid packet:", p))
+            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])
+        self.pg1.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg0.get_capture(1)
+        p = capture[0]
+        try:
+            self.assertEqual(p[IP].dst, self.pg0.remote_ip4)
+            inner = p[IPerror]
+            self.assertEqual(inner.src, self.pg0.remote_ip4)
+            self.assertEqual(inner[TCPerror].sport, local_port)
+        except:
+            self.logger.error(ppp("Unexpected or invalid packet:", p))
+            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))
+        self.pg1.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg0.get_capture(1)
+        p = capture[0]
+        try:
+            ip = p[IP]
+            tcp = p[TCP]
+            self.assertEqual(ip.dst, self.pg0.remote_ip4)
+            self.assertEqual(tcp.dport, local_port)
+            self.assert_packet_checksums_valid(p)
+        except:
+            self.logger.error(ppp("Unexpected or invalid packet:", p))
+            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))
+        self.pg0.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg1.get_capture(1)
+        p = capture[0]
+        try:
+            ip = p[IP]
+            tcp = p[TCP]
+            self.assertEqual(ip.src, self.pg0.remote_ip4)
+            self.assertEqual(tcp.sport, local_port)
+            self.assert_packet_checksums_valid(p)
+        except:
+            self.logger.error(ppp("Unexpected or invalid packet:", p))
+            raise
+
+    def test_static_lb(self):
+        """ 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}]
+
+        self.nat_add_address(self.nat_addr)
+        self.vapi.nat44_add_del_lb_static_mapping(
+            is_add=1,
+            external_addr=external_addr_n,
+            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)
+        self.vapi.nat44_interface_add_del_feature(
+            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))
+        self.pg1.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg0.get_capture(1)
+        p = capture[0]
+        server = None
+        try:
+            ip = p[IP]
+            tcp = p[TCP]
+            self.assertIn(ip.dst, [server1.ip4, server2.ip4])
+            if ip.dst == server1.ip4:
+                server = server1
+            else:
+                server = server2
+            self.assertEqual(tcp.dport, local_port)
+            self.assert_packet_checksums_valid(p)
+        except:
+            self.logger.error(ppp("Unexpected or invalid packet:", p))
+            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))
+        self.pg0.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg1.get_capture(1)
+        p = capture[0]
+        try:
+            ip = p[IP]
+            tcp = p[TCP]
+            self.assertEqual(ip.src, self.nat_addr)
+            self.assertEqual(tcp.sport, external_port)
+            self.assert_packet_checksums_valid(p)
+        except:
+            self.logger.error(ppp("Unexpected or invalid packet:", p))
+            raise
+
+        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.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),
+            ext_host_address=sessions[0].ext_host_address,
+            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) """
+        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}]
+
+        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)
+        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)
+        self.vapi.nat44_interface_add_del_feature(
+            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))
+        self.pg1.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg0.get_capture(1)
+        p = capture[0]
+        server = None
+        try:
+            ip = p[IP]
+            tcp = p[TCP]
+            self.assertIn(ip.dst, [server1.ip4, server2.ip4])
+            if ip.dst == server1.ip4:
+                server = server1
+            else:
+                server = server2
+            self.assertEqual(tcp.dport, local_port)
+            self.assert_packet_checksums_valid(p)
+        except:
+            self.logger.error(ppp("Unexpected or invalid packet:", p))
+            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))
+        self.pg0.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg1.get_capture(1)
+        p = capture[0]
+        try:
+            ip = p[IP]
+            tcp = p[TCP]
+            self.assertEqual(ip.src, self.nat_addr)
+            self.assertEqual(tcp.sport, external_port)
+            self.assert_packet_checksums_valid(p)
+        except:
+            self.logger.error(ppp("Unexpected or invalid packet:", p))
+            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))
+        self.pg1.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg0.get_capture(1)
+        p = capture[0]
+        server = None
+        try:
+            ip = p[IP]
+            tcp = p[TCP]
+            self.assertEqual(ip.dst, server1.ip4)
+            self.assertEqual(tcp.dport, local_port)
+            self.assert_packet_checksums_valid(p)
+        except:
+            self.logger.error(ppp("Unexpected or invalid packet:", p))
+            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))
+        self.pg0.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg1.get_capture(1)
+        p = capture[0]
+        try:
+            ip = p[IP]
+            tcp = p[TCP]
+            self.assertEqual(ip.src, server1.ip4)
+            self.assertEqual(tcp.sport, local_port)
+            self.assert_packet_checksums_valid(p)
+        except:
+            self.logger.error(ppp("Unexpected or invalid packet:", p))
+            raise
+
+    def test_lb_affinity(self):
+        """ 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}]
+
+        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)
+        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)
+        self.vapi.nat44_interface_add_del_feature(
+            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))
+        self.pg1.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg0.get_capture(1)
+        backend = capture[0][IP].dst
+
+        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.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),
+            ext_host_address=sessions[0].ext_host_address,
+            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))
+            pkts.append(p)
+        self.pg1.add_stream(pkts)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg0.get_capture(len(pkts))
+        for p in capture:
+            self.assertEqual(p[IP].dst, backend)
+
+    def test_multiple_vrf(self):
+        """ NAT44ED Multiple VRF setup """
+
+        external_addr = '1.2.3.4'
+        external_port = 80
+        local_port = 8080
+        port = 0
+
+        self.vapi.nat44_forwarding_enable_disable(enable=1)
+        self.nat_add_address(self.nat_addr)
+        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)
+        self.vapi.nat44_interface_add_del_feature(
+            sw_if_index=self.pg0.sw_if_index,
+            is_add=1, flags=flags)
+        self.vapi.nat44_interface_add_del_output_feature(
+            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)
+        self.vapi.nat44_interface_add_del_feature(
+            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)
+        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.pg0.remote_ip4,
+            external_sw_if_index=self.pg0.sw_if_index,
+            local_port=local_port,
+            vrf_id=0,
+            external_port=external_port,
+            proto=IP_PROTOS.tcp,
+            flags=flags
+        )
+
+        # from client to service (both VRF1)
+        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()
+        capture = self.pg5.get_capture(1)
+        p = capture[0]
+        try:
+            ip = p[IP]
+            tcp = p[TCP]
+            self.assertEqual(ip.dst, self.pg5.remote_ip4)
+            self.assertEqual(tcp.dport, local_port)
+            self.assert_packet_checksums_valid(p)
+        except:
+            self.logger.error(ppp("Unexpected or invalid packet:", p))
+            raise
+
+        # from service back to client (both VRF1)
+        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()
+        capture = self.pg6.get_capture(1)
+        p = capture[0]
+        try:
+            ip = p[IP]
+            tcp = p[TCP]
+            self.assertEqual(ip.src, external_addr)
+            self.assertEqual(tcp.sport, external_port)
+            self.assert_packet_checksums_valid(p)
+        except:
+            self.logger.error(ppp("Unexpected or invalid packet:", p))
+            raise
+
+        # dynamic NAT from VRF1 to VRF0 (output-feature)
+        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()
+        capture = self.pg1.get_capture(1)
+        p = capture[0]
+        try:
+            ip = p[IP]
+            tcp = p[TCP]
+            self.assertEqual(ip.src, self.nat_addr)
+            self.assert_packet_checksums_valid(p)
+            port = tcp.sport
+        except:
+            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))
+        self.pg1.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg5.get_capture(1)
+        p = capture[0]
+        try:
+            ip = p[IP]
+            tcp = p[TCP]
+            self.assertEqual(ip.dst, self.pg5.remote_ip4)
+            self.assertEqual(tcp.dport, 2345)
+            self.assert_packet_checksums_valid(p)
+        except:
+            self.logger.error(ppp("Unexpected or invalid packet:", p))
+            raise
+
+        # 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))
+        self.pg6.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg0.get_capture(1)
+        p = capture[0]
+        try:
+            ip = p[IP]
+            tcp = p[TCP]
+            self.assertEqual(ip.dst, self.pg0.remote_ip4)
+            self.assertEqual(tcp.dport, local_port)
+            self.assert_packet_checksums_valid(p)
+        except:
+            self.logger.error(ppp("Unexpected or invalid packet:", p))
+            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))
+        self.pg0.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg6.get_capture(1)
+        p = capture[0]
+        try:
+            ip = p[IP]
+            tcp = p[TCP]
+            self.assertEqual(ip.src, self.pg0.local_ip4)
+            self.assertEqual(tcp.sport, external_port)
+            self.assert_packet_checksums_valid(p)
+        except:
+            self.logger.error(ppp("Unexpected or invalid packet:", p))
+            raise
+
+        # 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))
+        self.pg0.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg5.get_capture(1)
+        p = capture[0]
+        try:
+            ip = p[IP]
+            tcp = p[TCP]
+            self.assertEqual(ip.dst, self.pg5.remote_ip4)
+            self.assertEqual(tcp.dport, local_port)
+            self.assert_packet_checksums_valid(p)
+        except:
+            self.logger.error(ppp("Unexpected or invalid packet:", p))
+            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))
+        self.pg5.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg0.get_capture(1)
+        p = capture[0]
+        try:
+            ip = p[IP]
+            tcp = p[TCP]
+            self.assertEqual(ip.src, external_addr)
+            self.assertEqual(tcp.sport, external_port)
+            self.assert_packet_checksums_valid(p)
+        except:
+            self.logger.error(ppp("Unexpected or invalid packet:", p))
+            raise
+
+        # 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))
+        self.pg6.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg5.get_capture(1)
+        p = capture[0]
+        try:
+            ip = p[IP]
+            tcp = p[TCP]
+            self.assertEqual(ip.dst, self.pg5.remote_ip4)
+            self.assertEqual(tcp.dport, local_port)
+            self.assert_packet_checksums_valid(p)
+        except:
+            self.logger.error(ppp("Unexpected or invalid packet:", p))
+            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))
+        self.pg5.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg6.get_capture(1)
+        p = capture[0]
+        try:
+            ip = p[IP]
+            tcp = p[TCP]
+            self.assertEqual(ip.src, self.pg5.remote_ip4)
+            self.assertEqual(tcp.sport, local_port)
+            self.assert_packet_checksums_valid(p)
+        except:
+            self.logger.error(ppp("Unexpected or invalid packet:", p))
+            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))
+        self.pg0.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg6.get_capture(1)
+        p = capture[0]
+        try:
+            ip = p[IP]
+            tcp = p[TCP]
+            self.assertEqual(ip.src, self.pg0.remote_ip4)
+            self.assertEqual(tcp.sport, local_port)
+            self.assert_packet_checksums_valid(p)
+        except:
+            self.logger.error(ppp("Unexpected or invalid packet:", p))
+            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))
+        self.pg0.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg6.get_capture(1)
+        p = capture[0]
+        try:
+            ip = p[IP]
+            tcp = p[TCP]
+            self.assertEqual(ip.src, self.pg0.remote_ip4)
+            self.assertEqual(tcp.sport, local_port)
+            self.assert_packet_checksums_valid(p)
+        except:
+            self.logger.error(ppp("Unexpected or invalid packet:", p))
+            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))
+        self.pg0.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg5.get_capture(1)
+        p = capture[0]
+        try:
+            ip = p[IP]
+            tcp = p[TCP]
+            self.assertEqual(ip.dst, self.pg5.remote_ip4)
+            self.assertEqual(tcp.dport, local_port)
+            self.assert_packet_checksums_valid(p)
+        except:
+            self.logger.error(ppp("Unexpected or invalid packet:", p))
+            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))
+        self.pg5.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg0.get_capture(1)
+        p = capture[0]
+        try:
+            ip = p[IP]
+            tcp = p[TCP]
+            self.assertEqual(ip.src, self.pg5.remote_ip4)
+            self.assertEqual(tcp.sport, local_port)
+            self.assert_packet_checksums_valid(p)
+        except:
+            self.logger.error(ppp("Unexpected or invalid packet:", p))
+            raise
+
+
+class TestNAT44EDMW(TestNAT44ED):
+    """ NAT44ED MW Test Case """
+    worker_config = "workers 1"
+
+    def get_stats_counter(self, path, worker=1):
+        return super(TestNAT44EDMW, self).get_stats_counter(path, worker)
+
+    @unittest.skip('MW fix required')
+    def test_users_dump(self):
+        """ NAT44ED API test - nat44_user_dump """
+
+    @unittest.skip('MW fix required')
+    def test_frag_out_of_order_do_not_translate(self):
+        """ NAT44ED don't translate fragments arriving out of order """
+
+    @unittest.skip('MW fix required')
+    def test_forwarding(self):
+        """ NAT44ED forwarding test """
+
+    @unittest.skip('MW fix required')
+    def test_twice_nat(self):
+        """ NAT44ED Twice NAT """
+
+    @unittest.skip('MW fix required')
+    def test_twice_nat_lb(self):
+        """ NAT44ED Twice NAT local service load balancing """
+
+    @unittest.skip('MW fix required')
+    def test_output_feature(self):
+        """ NAT44ED interface output feature (in2out postrouting) """
+
+    @unittest.skip('MW fix required')
+    def test_static_with_port_out2(self):
+        """ NAT44ED 1:1 NAPT asymmetrical rule """
+
+    @unittest.skip('MW fix required')
+    def test_output_feature_and_service2(self):
+        """ NAT44ED interface output feature and service host direct access """
+
+    @unittest.skip('MW fix required')
+    def test_static_lb(self):
+        """ NAT44ED local service load balancing """
+
+    @unittest.skip('MW fix required')
+    def test_static_lb_2(self):
+        """ NAT44ED local service load balancing (asymmetrical rule) """
+
+    @unittest.skip('MW fix required')
+    def test_lb_affinity(self):
+        """ NAT44ED local service load balancing affinity """
+
+    @unittest.skip('MW fix required')
+    def test_multiple_vrf(self):
+        """ NAT44ED Multiple VRF setup """
+
+    @unittest.skip('MW fix required')
+    def test_self_twice_nat_positive(self):
+        """ NAT44ED Self Twice NAT (positive test) """
+
+    @unittest.skip('MW fix required')
+    def test_self_twice_nat_lb_positive(self):
+        """ NAT44ED Self Twice NAT local service load balancing (positive test)
+        """
+
+    def test_dynamic(self):
+        """ NAT44ED dynamic translation test """
+
+        self.nat_add_address(self.nat_addr)
+        self.nat_add_inside_interface(self.pg0)
+        self.nat_add_outside_interface(self.pg1)
+
+        # in2out
+        tc1 = self.get_stats_counter('/nat44/ed/in2out/slowpath/tcp')
+        uc1 = self.get_stats_counter('/nat44/ed/in2out/slowpath/udp')
+        ic1 = self.get_stats_counter('/nat44/ed/in2out/slowpath/icmp')
+        dc1 = self.get_stats_counter('/nat44/ed/in2out/slowpath/drops')
+
+        pkts = self.create_stream_in(self.pg0, self.pg1)
+        # TODO: specify worker=idx, also stats have to
+        #       know from which worker to take capture
+        self.pg0.add_stream(pkts)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg1.get_capture(len(pkts))
+        self.verify_capture_out(capture, ignore_port=True)
+
+        if_idx = self.pg0.sw_if_index
+        tc2 = self.get_stats_counter('/nat44/ed/in2out/slowpath/tcp')
+        uc2 = self.get_stats_counter('/nat44/ed/in2out/slowpath/udp')
+        ic2 = self.get_stats_counter('/nat44/ed/in2out/slowpath/icmp')
+        dc2 = self.get_stats_counter('/nat44/ed/in2out/slowpath/drops')
+
+        self.assertEqual(tc2[if_idx] - tc1[if_idx], 2)
+        self.assertEqual(uc2[if_idx] - uc1[if_idx], 1)
+        self.assertEqual(ic2[if_idx] - ic1[if_idx], 1)
+        self.assertEqual(dc2[if_idx] - dc1[if_idx], 0)
+
+        # out2in
+        tc1 = self.get_stats_counter('/nat44/ed/out2in/fastpath/tcp')
+        uc1 = self.get_stats_counter('/nat44/ed/out2in/fastpath/udp')
+        ic1 = self.get_stats_counter('/nat44/ed/out2in/slowpath/icmp')
+        dc1 = self.get_stats_counter('/nat44/ed/out2in/fastpath/drops')
+
+        pkts = self.create_stream_out(self.pg1)
+        self.pg1.add_stream(pkts)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg0.get_capture(len(pkts))
+        self.verify_capture_in(capture, self.pg0)
+
+        if_idx = self.pg1.sw_if_index
+        tc2 = self.get_stats_counter('/nat44/ed/out2in/fastpath/tcp')
+        uc2 = self.get_stats_counter('/nat44/ed/out2in/fastpath/udp')
+        ic2 = self.get_stats_counter('/nat44/ed/out2in/slowpath/icmp')
+        dc2 = self.get_stats_counter('/nat44/ed/out2in/fastpath/drops')
+
+        self.assertEqual(tc2[if_idx] - tc1[if_idx], 2)
+        self.assertEqual(uc2[if_idx] - uc1[if_idx], 1)
+        self.assertEqual(ic2[if_idx] - ic1[if_idx], 1)
+        self.assertEqual(dc2[if_idx] - dc1[if_idx], 0)
+
+        sc = self.get_stats_counter('/nat44/total-sessions')
+        self.assertEqual(sc[0], 3)
+
+    def test_frag_in_order(self):
+        """ NAT44ED translate fragments arriving in order """
+
+        self.nat_add_address(self.nat_addr)
+        self.nat_add_inside_interface(self.pg0)
+        self.nat_add_outside_interface(self.pg1)
+
+        self.frag_in_order(proto=IP_PROTOS.tcp, ignore_port=True)
+        self.frag_in_order(proto=IP_PROTOS.udp, ignore_port=True)
+        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 """
+
+        self.nat_add_address(self.nat_addr)
+        self.nat_add_inside_interface(self.pg0)
+        self.nat_add_outside_interface(self.pg1)
+        self.vapi.nat44_forwarding_enable_disable(enable=True)
+
+        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 """
+
+        self.nat_add_address(self.nat_addr)
+        self.nat_add_inside_interface(self.pg0)
+        self.nat_add_outside_interface(self.pg1)
+
+        self.frag_out_of_order(proto=IP_PROTOS.tcp, ignore_port=True)
+        self.frag_out_of_order(proto=IP_PROTOS.udp, ignore_port=True)
+        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 """
+
+        in_port = self.random_port()
+        out_port = self.random_port()
+
+        self.nat_add_address(self.nat_addr)
+        self.nat_add_inside_interface(self.pg0)
+        self.nat_add_outside_interface(self.pg0)
+        self.nat_add_inside_interface(self.pg1)
+        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)
+
+        # 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)
+
+    def test_frag_out_of_order_in_plus_out(self):
+        """ NAT44ED in+out interface fragments out of order """
+
+        in_port = self.random_port()
+        out_port = self.random_port()
+
+        self.nat_add_address(self.nat_addr)
+        self.nat_add_inside_interface(self.pg0)
+        self.nat_add_outside_interface(self.pg0)
+        self.nat_add_inside_interface(self.pg1)
+        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)
+
+        # 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)
+
+    def test_reass_hairpinning(self):
+        """ NAT44ED fragments hairpinning """
+
+        server_addr = self.pg0.remote_hosts[1].ip4
+
+        host_in_port = self.random_port()
+        server_in_port = self.random_port()
+        server_out_port = self.random_port()
+
+        self.nat_add_address(self.nat_addr)
+        self.nat_add_inside_interface(self.pg0)
+        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)
+
+        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 """
+
+        inside = self.pg0
+        inside_vrf10 = self.pg2
+        outside = self.pg1
+
+        limit = 5
+
+        # 2 interfaces pg0, pg1 (vrf10, limit 1 tcp session)
+        # non existing vrf_id makes process core dump
+        self.vapi.nat44_set_session_limit(session_limit=limit, vrf_id=10)
+
+        self.nat_add_inside_interface(inside)
+        self.nat_add_inside_interface(inside_vrf10)
+        self.nat_add_outside_interface(outside)
+
+        # vrf independent
+        self.nat_add_interface_address(outside)
+
+        # BUG: causing core dump - when bad vrf_id is specified
+        # self.nat_add_address(outside.local_ip4, vrf_id=20)
+
+        stream = self.create_tcp_stream(inside_vrf10, outside, limit * 2)
+        inside_vrf10.add_stream(stream)
+
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+
+        capture = outside.get_capture(limit)
+
+        stream = self.create_tcp_stream(inside, outside, limit * 2)
+        inside.add_stream(stream)
+
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+
+        capture = outside.get_capture(len(stream))
+
+    def test_clear_sessions(self):
+        """ NAT44ED session clearing test """
+
+        self.nat_add_address(self.nat_addr)
+        self.nat_add_inside_interface(self.pg0)
+        self.nat_add_outside_interface(self.pg1)
+
+        pkts = self.create_stream_in(self.pg0, self.pg1)
+        self.pg0.add_stream(pkts)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg1.get_capture(len(pkts))
+        self.verify_capture_out(capture, ignore_port=True)
+
+        sessions = self.get_stats_counter('/nat44/total-sessions')
+        self.assertTrue(sessions[0] > 0)
+
+        self.vapi.cli("clear nat44 sessions")
+
+        sessions = self.get_stats_counter('/nat44/total-sessions')
+        self.assertEqual(sessions[0], 0)
+
+    def test_show_max_translations(self):
+        """ NAT44ED API test - max translations per thread """
+        nat_config = self.vapi.nat_show_config_2()
+        self.assertEqual(self.max_sessions,
+                         nat_config.max_translations_per_thread)
+
+    def test_lru_cleanup(self):
+        """ 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)
+
+        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))
+            pkts.append(p)
+
+        self.pg0.add_stream(pkts)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        self.pg1.get_capture(len(pkts))
+        self.sleep(1.5, "wait for timeouts")
+
+        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'))
+            pkts.append(p)
+
+        self.pg0.add_stream(pkts)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        self.pg1.get_capture(len(pkts))
+
+    def test_session_rst_timeout(self):
+        """ 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.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.pg0.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        self.pg1.get_capture(1)
+
+        self.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 + 1, dport=self.tcp_external_port + 1,
+                 flags="S"))
+        self.pg0.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        self.pg1.get_capture(1)
+
+    def test_dynamic_out_of_ports(self):
+        """ NAT44ED dynamic translation test: out of ports """
+
+        self.nat_add_inside_interface(self.pg0)
+        self.nat_add_outside_interface(self.pg1)
+
+        # in2out and no NAT addresses added
+        err_old = self.statistics.get_err_counter(
+            '/err/nat44-ed-in2out-slowpath/out of ports')
+
+        pkts = self.create_stream_in(self.pg0, self.pg1)
+        self.pg0.add_stream(pkts)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        self.pg1.get_capture(0, timeout=1)
+
+        err_new = self.statistics.get_err_counter(
+            '/err/nat44-ed-in2out-slowpath/out of ports')
+
+        self.assertEqual(err_new - err_old, len(pkts))
+
+        # in2out after NAT addresses added
+        self.nat_add_address(self.nat_addr)
+
+        err_old = self.statistics.get_err_counter(
+            '/err/nat44-ed-in2out-slowpath/out of ports')
+
+        pkts = self.create_stream_in(self.pg0, self.pg1)
+        self.pg0.add_stream(pkts)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg1.get_capture(len(pkts))
+        self.verify_capture_out(capture, ignore_port=True)
+
+        err_new = self.statistics.get_err_counter(
+            '/err/nat44-ed-in2out-slowpath/out of ports')
+
+        self.assertEqual(err_new, err_old)
+
+    def test_unknown_proto(self):
+        """ 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))
+        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))
+        self.pg0.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        p = self.pg1.get_capture(1)
+        packet = p[0]
+        try:
+            self.assertEqual(packet[IP].src, self.nat_addr)
+            self.assertEqual(packet[IP].dst, self.pg1.remote_ip4)
+            self.assertEqual(packet.haslayer(GRE), 1)
+            self.assert_packet_checksums_valid(packet)
+        except:
+            self.logger.error(ppp("Unexpected or invalid packet:", packet))
+            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))
+        self.pg1.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        p = self.pg0.get_capture(1)
+        packet = p[0]
+        try:
+            self.assertEqual(packet[IP].src, self.pg1.remote_ip4)
+            self.assertEqual(packet[IP].dst, self.pg0.remote_ip4)
+            self.assertEqual(packet.haslayer(GRE), 1)
+            self.assert_packet_checksums_valid(packet)
+        except:
+            self.logger.error(ppp("Unexpected or invalid packet:", packet))
+            raise
+
+    def test_hairpinning_unknown_proto(self):
+        """ NAT44ED translate packet with unknown protocol - hairpinning """
+        host = self.pg0.remote_hosts[0]
+        server = self.pg0.remote_hosts[1]
+        host_in_port = 1234
+        server_out_port = 8765
+        server_nat_ip = "10.0.0.11"
+
+        self.nat_add_address(self.nat_addr)
+        self.nat_add_inside_interface(self.pg0)
+        self.nat_add_outside_interface(self.pg1)
+
+        # add static mapping for server
+        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))
+        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))
+        self.pg0.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        p = self.pg0.get_capture(1)
+        packet = p[0]
+        try:
+            self.assertEqual(packet[IP].src, self.nat_addr)
+            self.assertEqual(packet[IP].dst, server.ip4)
+            self.assertEqual(packet.haslayer(GRE), 1)
+            self.assert_packet_checksums_valid(packet)
+        except:
+            self.logger.error(ppp("Unexpected or invalid packet:", packet))
+            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))
+        self.pg0.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        p = self.pg0.get_capture(1)
+        packet = p[0]
+        try:
+            self.assertEqual(packet[IP].src, server_nat_ip)
+            self.assertEqual(packet[IP].dst, host.ip4)
+            self.assertEqual(packet.haslayer(GRE), 1)
+            self.assert_packet_checksums_valid(packet)
+        except:
+            self.logger.error(ppp("Unexpected or invalid packet:", packet))
+            raise
+
+    def test_output_feature_and_service(self):
+        """ NAT44ED interface output feature and services """
+        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_ADDR_ONLY
+        self.vapi.nat44_add_del_identity_mapping(
+            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_inside_interface(self.pg0)
+        self.nat_add_outside_interface(self.pg0)
+        self.vapi.nat44_interface_add_del_output_feature(
+            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))
+        self.pg1.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg0.get_capture(1)
+        p = capture[0]
+        try:
+            ip = p[IP]
+            tcp = p[TCP]
+            self.assertEqual(ip.dst, self.pg0.remote_ip4)
+            self.assertEqual(tcp.dport, local_port)
+            self.assert_packet_checksums_valid(p)
+        except:
+            self.logger.error(ppp("Unexpected or invalid packet:", p))
+            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))
+        self.pg0.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg1.get_capture(1)
+        p = capture[0]
+        try:
+            ip = p[IP]
+            tcp = p[TCP]
+            self.assertEqual(ip.src, external_addr)
+            self.assertEqual(tcp.sport, external_port)
+            self.assert_packet_checksums_valid(p)
+        except:
+            self.logger.error(ppp("Unexpected or invalid packet:", p))
+            raise
+
+        # from local network host to external network
+        pkts = self.create_stream_in(self.pg0, self.pg1)
+        self.pg0.add_stream(pkts)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg1.get_capture(len(pkts))
+        self.verify_capture_out(capture, ignore_port=True)
+        pkts = self.create_stream_in(self.pg0, self.pg1)
+        self.pg0.add_stream(pkts)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg1.get_capture(len(pkts))
+        self.verify_capture_out(capture, ignore_port=True)
+
+        # from external network back to local network host
+        pkts = self.create_stream_out(self.pg1)
+        self.pg1.add_stream(pkts)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg0.get_capture(len(pkts))
+        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'
+        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_inside_interface(self.pg0)
+        self.nat_add_outside_interface(self.pg0)
+        self.vapi.nat44_interface_add_del_output_feature(
+            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))
+        self.pg0.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg1.get_capture(1)
+        p = capture[0]
+        try:
+            ip = p[IP]
+            tcp = p[TCP]
+            self.assertEqual(ip.src, self.pg0.remote_ip4)
+            self.assertEqual(tcp.sport, 12345)
+            self.assertEqual(ip.dst, self.pg1.remote_ip4)
+            self.assertEqual(tcp.dport, local_port)
+            self.assert_packet_checksums_valid(p)
+        except:
+            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))
+        self.pg1.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg0.get_capture(1)
+        p = capture[0]
+        try:
+            ip = p[IP]
+            tcp = p[TCP]
+            self.assertEqual(ip.src, external_addr)
+            self.assertEqual(tcp.sport, external_port)
+            self.assertEqual(ip.dst, self.pg0.remote_ip4)
+            self.assertEqual(tcp.dport, 12345)
+            self.assert_packet_checksums_valid(p)
+        except:
+            self.logger.error(ppp("Unexpected or invalid packet:", p))
+            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)
+
+    def test_self_twice_nat_negative(self):
+        """ 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"""
+
+        external_addr = self.nat_addr
+        external_port = 80
+        local_port = 8080
+        server1 = self.pg0.remote_hosts[0]
+        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}]
+
+        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)
+        self.vapi.nat44_interface_add_del_feature(
+            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)
+
+        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))
+            pkts.append(p)
+        self.pg1.add_stream(pkts)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg0.get_capture(len(pkts))
+        for p in capture:
+            if p[IP].dst == server1.ip4:
+                server1_n += 1
+            else:
+                server2_n += 1
+        self.assertGreater(server1_n, server2_n)
+
+        local = {
+            'addr': server3.ip4,
+            'port': local_port,
+            'probability': 20,
+            'vrf_id': 0
+        }
+
+        # add new back-end
+        self.vapi.nat44_lb_static_mapping_add_del_local(
+            is_add=1,
+            external_addr=external_addr,
+            external_port=external_port,
+            local=local,
+            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))
+            pkts.append(p)
+        self.assertGreater(len(pkts), 0)
+        self.pg1.add_stream(pkts)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg0.get_capture(len(pkts))
+        for p in capture:
+            if p[IP].dst == server1.ip4:
+                server1_n += 1
+            elif p[IP].dst == server2.ip4:
+                server2_n += 1
+            else:
+                server3_n += 1
+        self.assertGreater(server1_n, 0)
+        self.assertGreater(server2_n, 0)
+        self.assertGreater(server3_n, 0)
+
+        local = {
+            'addr': server2.ip4,
+            'port': local_port,
+            'probability': 10,
+            'vrf_id': 0
+        }
+
+        # remove one back-end
+        self.vapi.nat44_lb_static_mapping_add_del_local(
+            is_add=0,
+            external_addr=external_addr,
+            external_port=external_port,
+            local=local,
+            protocol=IP_PROTOS.tcp)
+        server1_n = 0
+        server2_n = 0
+        server3_n = 0
+        self.pg1.add_stream(pkts)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg0.get_capture(len(pkts))
+        for p in capture:
+            if p[IP].dst == server1.ip4:
+                server1_n += 1
+            elif p[IP].dst == server2.ip4:
+                server2_n += 1
+            else:
+                server3_n += 1
+        self.assertGreater(server1_n, 0)
+        self.assertEqual(server2_n, 0)
+        self.assertGreater(server3_n, 0)
+
+    def test_syslog_sess(self):
+        """ 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))
+        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)
+
+        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, False)
+
+    def test_twice_nat_interface_addr(self):
+        """ 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)
+
+        # no address in NAT pool
+        adresses = self.vapi.nat44_address_dump()
+        self.assertEqual(0, len(adresses))
+
+        # configure interface address and check NAT address pool
+        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(adresses[0].flags, flags)
+
+        # remove interface address and check NAT address pool
+        self.pg11.unconfig_ip4()
+        adresses = self.vapi.nat44_address_dump()
+        self.assertEqual(0, len(adresses))
+
+    def test_output_feature_stateful_acl(self):
+        """ NAT44ED output feature works with stateful ACL """
+
+        self.nat_add_address(self.nat_addr)
+        self.vapi.nat44_interface_add_del_output_feature(
+            sw_if_index=self.pg0.sw_if_index,
+            flags=self.config_flags.NAT_IS_INSIDE, is_add=1)
+        self.vapi.nat44_interface_add_del_output_feature(
+            sw_if_index=self.pg1.sw_if_index,
+            flags=self.config_flags.NAT_IS_OUTSIDE, is_add=1)
+
+        # First ensure that the NAT is working sans ACL
+
+        # send packets out2in, no sessions yet so packets should drop
+        pkts_out2in = self.create_stream_out(self.pg1)
+        self.send_and_assert_no_replies(self.pg1, pkts_out2in)
+
+        # 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))
+        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))
+        self.verify_capture_in(capture, self.pg0)
+
+        # Create an ACL blocking everything
+        out2in_deny_rule = AclRule(is_permit=0)
+        out2in_acl = VppAcl(self, rules=[out2in_deny_rule])
+        out2in_acl.add_vpp_config()
+
+        # create an ACL to permit/reflect everything
+        in2out_reflect_rule = AclRule(is_permit=2)
+        in2out_acl = VppAcl(self, rules=[in2out_reflect_rule])
+        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.add_vpp_config()
+        self.send_and_assert_no_replies(self.pg1, pkts_out2in)
+
+        # apply output acl
+        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))
+        self.verify_capture_out(capture, ignore_port=True)
+
+        # send out2in again. ACL state exists so it should work now.
+        # TCP packets with the syn flag set also need the ack flag
+        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))
+        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 """
+        old_timeouts = self.vapi.nat_get_timeouts()
+        new_transitory = 2
+        self.vapi.nat_set_timeouts(
+            udp=old_timeouts.udp,
+            tcp_established=old_timeouts.tcp_established,
+            icmp=old_timeouts.icmp,
+            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'
+        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)
+        self.vapi.nat44_interface_add_del_feature(
+            sw_if_index=self.pg0.sw_if_index,
+            flags=flags, is_add=1)
+        self.vapi.nat44_interface_add_del_output_feature(
+            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"))
+        self.pg1.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg0.get_capture(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"))
+        self.pg0.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        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=service_ip) /
+             TCP(sport=33898, dport=80, flags="A"))
+        self.pg1.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        self.pg0.get_capture(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))
+        self.pg0.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        self.pg1.get_capture(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))
+        self.pg1.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        self.pg0.get_capture(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))
+        self.pg0.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        self.pg1.get_capture(1)
+
+        # session now in transitory timeout
+        # try SYN packet out->in - should be dropped
+        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"))
+        self.pg1.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+
+        self.sleep(new_transitory, "wait for transitory timeout")
+        self.pg0.assert_nothing_captured(0)
+
+        # session should still exist
+        sessions = self.vapi.nat44_user_session_dump(self.pg0.remote_ip4, 0)
+        self.assertEqual(len(sessions) - start_sessnum, 1)
+
+        # 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))
+        self.pg1.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+
+        sessions = self.vapi.nat44_user_session_dump(self.pg0.remote_ip4, 0)
+        self.assertEqual(len(sessions) - start_sessnum, 0)
+        self.pg0.assert_nothing_captured(0)
+
+    def test_tcp_session_close_in(self):
+        """ NAT44ED Close TCP session from inside network """
+
+        in_port = self.tcp_port_in
+        out_port = 10505
+        ext_port = self.tcp_external_port
+
+        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)
+
+        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.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))
+        self.pg0.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        self.pg1.get_capture(1)
+
+        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))
+        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))
+        pkts.append(p)
+
+        self.pg1.add_stream(pkts)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        self.pg0.get_capture(2)
+
+        # 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))
+        self.pg0.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        self.pg1.get_capture(1)
+
+        sessions = self.vapi.nat44_user_session_dump(self.pg0.remote_ip4, 0)
+        self.assertEqual(len(sessions) - session_n, 1)
+
+        out2in_drops = self.get_err_counter(
+            '/err/nat44-ed-out2in/drops due to TCP in transitory timeout')
+        in2out_drops = self.get_err_counter(
+            '/err/nat44-ed-in2out/drops due to TCP in transitory timeout')
+
+        # extra FIN packet out -> in - this should be dropped
+        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.pg1.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        self.pg0.assert_nothing_captured()
+
+        # extra ACK packet in -> out - this should be dropped
+        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.pg0.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        self.pg1.assert_nothing_captured()
+
+        stats = self.get_err_counter(
+            '/err/nat44-ed-out2in/drops due to TCP in transitory timeout')
+        self.assertEqual(stats - out2in_drops, 1)
+        stats = self.get_err_counter(
+            '/err/nat44-ed-in2out/drops due to TCP in transitory timeout')
+        self.assertEqual(stats - in2out_drops, 1)
+
+        self.sleep(3)
+        # extra 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))
+        self.pg0.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        self.pg1.assert_nothing_captured()
+        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 """
+
+        in_port = self.tcp_port_in
+        out_port = 10505
+        ext_port = self.tcp_external_port
+
+        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)
+
+        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.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))
+        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))
+
+        self.pg0.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        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))
+        self.pg1.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        self.pg0.get_capture(1)
+
+        sessions = self.vapi.nat44_user_session_dump(self.pg0.remote_ip4, 0)
+        self.assertEqual(len(sessions) - session_n, 1)
+
+        out2in_drops = self.get_err_counter(
+            '/err/nat44-ed-out2in/drops due to TCP in transitory timeout')
+        in2out_drops = self.get_err_counter(
+            '/err/nat44-ed-in2out/drops due to TCP in transitory timeout')
+
+        # extra FIN packet out -> in - this should be dropped
+        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.pg1.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        self.pg0.assert_nothing_captured()
+
+        # extra ACK packet in -> out - this should be dropped
+        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.pg0.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        self.pg1.assert_nothing_captured()
+
+        stats = self.get_err_counter(
+            '/err/nat44-ed-out2in/drops due to TCP in transitory timeout')
+        self.assertEqual(stats - out2in_drops, 1)
+        stats = self.get_err_counter(
+            '/err/nat44-ed-in2out/drops due to TCP in transitory timeout')
+        self.assertEqual(stats - in2out_drops, 1)
+
+        self.sleep(3)
+        # extra 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))
+        self.pg0.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        self.pg1.assert_nothing_captured()
+        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):
+        """ NAT44ED Close TCP session from inside network """
+
+        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)
+
+        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)
+
+        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))
+        self.pg0.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        self.pg1.get_capture(1)
+
+        # 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))
+        self.pg1.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        self.pg0.get_capture(1)
+
+        # 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))
+        self.pg0.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        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=301, ack=101))
+        self.pg1.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        self.pg0.get_capture(1)
+
+        sessions = self.vapi.nat44_user_session_dump(self.pg0.remote_ip4, 0)
+        self.assertEqual(len(sessions) - session_n, 1)
+
+        out2in_drops = self.get_err_counter(
+            '/err/nat44-ed-out2in/drops due to TCP in transitory timeout')
+        in2out_drops = self.get_err_counter(
+            '/err/nat44-ed-in2out/drops due to TCP in transitory timeout')
+
+        # extra FIN packet out -> in - this should be dropped
+        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.pg1.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        self.pg0.assert_nothing_captured()
+
+        # extra ACK packet in -> out - this should be dropped
+        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.pg0.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        self.pg1.assert_nothing_captured()
+
+        stats = self.get_err_counter(
+            '/err/nat44-ed-out2in/drops due to TCP in transitory timeout')
+        self.assertEqual(stats - out2in_drops, 1)
+        stats = self.get_err_counter(
+            '/err/nat44-ed-in2out/drops due to TCP in transitory timeout')
+        self.assertEqual(stats - in2out_drops, 1)
+
+        self.sleep(3)
+        # extra 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))
+        self.pg0.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        self.pg1.assert_nothing_captured()
+        sessions = self.vapi.nat44_user_session_dump(self.pg0.remote_ip4, 0)
+        self.assertEqual(len(sessions) - session_n, 0)
+
+    def test_dynamic_output_feature_vrf(self):
+        """ NAT44ED dynamic translation test: output-feature, VRF"""
+
+        # other then default (0)
+        new_vrf_id = 22
+
+        self.nat_add_address(self.nat_addr)
+        flags = self.config_flags.NAT_IS_INSIDE
+        self.vapi.nat44_interface_add_del_output_feature(
+            sw_if_index=self.pg7.sw_if_index,
+            flags=flags, is_add=1)
+        self.vapi.nat44_interface_add_del_output_feature(
+            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.get_stats_counter(
+                '/nat44/ed/in2out/slowpath/tcp')
+            udpn = self.get_stats_counter(
+                '/nat44/ed/in2out/slowpath/udp')
+            icmpn = self.get_stats_counter(
+                '/nat44/ed/in2out/slowpath/icmp')
+            drops = self.get_stats_counter(
+                '/nat44/ed/in2out/slowpath/drops')
+
+            pkts = self.create_stream_in(self.pg7, self.pg8)
+            self.pg7.add_stream(pkts)
+            self.pg_enable_capture(self.pg_interfaces)
+            self.pg_start()
+            capture = self.pg8.get_capture(len(pkts))
+            self.verify_capture_out(capture, ignore_port=True)
+
+            if_idx = self.pg7.sw_if_index
+            cnt = self.get_stats_counter(
+                '/nat44/ed/in2out/slowpath/tcp')
+            self.assertEqual(cnt[if_idx] - tcpn[if_idx], 2)
+            cnt = self.get_stats_counter(
+                '/nat44/ed/in2out/slowpath/udp')
+            self.assertEqual(cnt[if_idx] - udpn[if_idx], 1)
+            cnt = self.get_stats_counter(
+                '/nat44/ed/in2out/slowpath/icmp')
+            self.assertEqual(cnt[if_idx] - icmpn[if_idx], 1)
+            cnt = self.get_stats_counter(
+                '/nat44/ed/in2out/slowpath/drops')
+            self.assertEqual(cnt[if_idx] - drops[if_idx], 0)
+
+            # out2in
+            tcpn = self.get_stats_counter(
+                '/nat44/ed/out2in/fastpath/tcp')
+            udpn = self.get_stats_counter(
+                '/nat44/ed/out2in/fastpath/udp')
+            icmpn = self.get_stats_counter(
+                '/nat44/ed/out2in/slowpath/icmp')
+            drops = self.get_stats_counter(
+                '/nat44/ed/out2in/fastpath/drops')
+
+            pkts = self.create_stream_out(self.pg8)
+            self.pg8.add_stream(pkts)
+            self.pg_enable_capture(self.pg_interfaces)
+            self.pg_start()
+            capture = self.pg7.get_capture(len(pkts))
+            self.verify_capture_in(capture, self.pg7)
+
+            if_idx = self.pg8.sw_if_index
+            cnt = self.get_stats_counter(
+                '/nat44/ed/out2in/fastpath/tcp')
+            self.assertEqual(cnt[if_idx] - tcpn[if_idx], 2)
+            cnt = self.get_stats_counter(
+                '/nat44/ed/out2in/fastpath/udp')
+            self.assertEqual(cnt[if_idx] - udpn[if_idx], 1)
+            cnt = self.get_stats_counter(
+                '/nat44/ed/out2in/slowpath/icmp')
+            self.assertEqual(cnt[if_idx] - icmpn[if_idx], 1)
+            cnt = self.get_stats_counter(
+                '/nat44/ed/out2in/fastpath/drops')
+            self.assertEqual(cnt[if_idx] - drops[if_idx], 0)
+
+            sessions = self.get_stats_counter('/nat44/total-sessions')
+            self.assertEqual(sessions[0], 3)
+
+        finally:
+            self.configure_ip4_interface(self.pg7, table_id=0)
+            self.configure_ip4_interface(self.pg8, table_id=0)
+
+            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. """
+
+        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)
+        self.vapi.nat44_interface_add_del_feature(
+            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))
+        self.pg6.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg6.get_capture(1)
+        p = capture[0]
+        try:
+            ip = p[IP]
+            tcp = p[TCP]
+            self.assertEqual(ip.src, twice_nat_addr)
+            self.assertNotEqual(tcp.sport, 12345)
+            post_twice_nat_port = tcp.sport
+            self.assertEqual(ip.dst, self.pg6.remote_ip4)
+            self.assertEqual(tcp.dport, local_port)
+            self.assert_packet_checksums_valid(p)
+        except:
+            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))
+        self.pg6.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg6.get_capture(1)
+        p = capture[0]
+        try:
+            ip = p[IP]
+            tcp = p[TCP]
+            self.assertEqual(ip.src, self.pg1.remote_ip4)
+            self.assertEqual(tcp.sport, external_port)
+            self.assertEqual(ip.dst, self.pg6.remote_ip4)
+            self.assertEqual(tcp.dport, 12345)
+            self.assert_packet_checksums_valid(p)
+        except:
+            self.logger.error(ppp("Unexpected or invalid packet:", p))
+            raise
+
+    def test_one_armed_nat44_static(self):
+        """ NAT44ED One armed NAT and 1:1 NAPT asymmetrical rule """
+
+        remote_host = self.pg4.remote_hosts[0]
+        local_host = self.pg4.remote_hosts[1]
+        external_port = 80
+        local_port = 8080
+        eh_port_in = 0
+
+        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_INSIDE
+        self.vapi.nat44_interface_add_del_feature(
+            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)
+
+        # 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))
+        self.pg4.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg4.get_capture(1)
+        p = capture[0]
+        try:
+            ip = p[IP]
+            tcp = p[TCP]
+            self.assertEqual(ip.dst, local_host.ip4)
+            self.assertEqual(ip.src, self.nat_addr)
+            self.assertEqual(tcp.dport, local_port)
+            self.assertNotEqual(tcp.sport, 12345)
+            eh_port_in = tcp.sport
+            self.assert_packet_checksums_valid(p)
+        except:
+            self.logger.error(ppp("Unexpected or invalid packet:", p))
+            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))
+        self.pg4.add_stream(p)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        capture = self.pg4.get_capture(1)
+        p = capture[0]
+        try:
+            ip = p[IP]
+            tcp = p[TCP]
+            self.assertEqual(ip.src, self.nat_addr)
+            self.assertEqual(ip.dst, remote_host.ip4)
+            self.assertEqual(tcp.sport, external_port)
+            self.assertEqual(tcp.dport, 12345)
+            self.assert_packet_checksums_valid(p)
+        except:
+            self.logger.error(ppp("Unexpected or invalid packet:", p))
+            raise
+
+
+if __name__ == '__main__':
+    unittest.main(testRunner=VppTestRunner)