ip: allow the 'ip6 enable' on tunnel interface types
[vpp.git] / test / test_ip6.py
index e6067f6..6eabf5a 100644 (file)
@@ -7,32 +7,36 @@ import unittest
 from parameterized import parameterized
 import scapy.compat
 import scapy.layers.inet6 as inet6
+from scapy.layers.inet import UDP, IP
 from scapy.contrib.mpls import MPLS
 from scapy.layers.inet6 import IPv6, ICMPv6ND_NS, ICMPv6ND_RS, \
     ICMPv6ND_RA, ICMPv6NDOptMTU, ICMPv6NDOptSrcLLAddr, ICMPv6NDOptPrefixInfo, \
     ICMPv6ND_NA, ICMPv6NDOptDstLLAddr, ICMPv6DestUnreach, icmp6types, \
     ICMPv6TimeExceeded, ICMPv6EchoRequest, ICMPv6EchoReply, \
     IPv6ExtHdrHopByHop, ICMPv6MLReport2, ICMPv6MLDMultAddrRec
-from scapy.layers.l2 import Ether, Dot1Q
+from scapy.layers.l2 import Ether, Dot1Q, GRE
 from scapy.packet import Raw
 from scapy.utils6 import in6_getnsma, in6_getnsmac, in6_ptop, in6_islladdr, \
     in6_mactoifaceid
 from six import moves
 
-from framework import VppTestCase, VppTestRunner
+from framework import VppTestCase, VppTestRunner, tag_run_solo
 from util import ppp, ip6_normalize, mk_ll_addr
 from vpp_papi import VppEnum
-from vpp_ip import DpoProto, VppIpPuntPolicer, VppIpPuntRedirect
+from vpp_ip import DpoProto, VppIpPuntPolicer, VppIpPuntRedirect, VppIpPathMtu
 from vpp_ip_route import VppIpRoute, VppRoutePath, find_route, VppIpMRoute, \
     VppMRoutePath, VppMplsIpBind, \
     VppMplsRoute, VppMplsTable, VppIpTable, FibPathType, FibPathProto, \
     VppIpInterfaceAddress, find_route_in_dump, find_mroute_in_dump, \
-    VppIp6LinkLocalAddress
+    VppIp6LinkLocalAddress, VppIpRouteV2
 from vpp_neighbor import find_nbr, VppNeighbor
+from vpp_ipip_tun_interface import VppIpIpTunInterface
 from vpp_pg_interface import is_ipv6_misc
 from vpp_sub_interface import VppSubInterface, VppDot1QSubint
-from vpp_policer import VppPolicer
+from vpp_policer import VppPolicer, PolicerAction
 from ipaddress import IPv6Network, IPv6Address
+from vpp_gre_interface import VppGreInterface
+from vpp_teib import VppTeib
 
 AF_INET6 = socket.AF_INET6
 
@@ -162,13 +166,10 @@ class TestIPv6ND(VppTestCase):
         self.assertEqual(ip.dst, dip)
 
 
+@tag_run_solo
 class TestIPv6(TestIPv6ND):
     """ IPv6 Test Case """
 
-    @classmethod
-    def force_solo(cls):
-        return True
-
     @classmethod
     def setUpClass(cls):
         super(TestIPv6, cls).setUpClass()
@@ -505,6 +506,18 @@ class TestIPv6(TestIPv6ND):
                                 dst_ip=self.pg0._remote_hosts[3].ip6_ll,
                                 tgt_ip=self.pg0.local_ip6_ll)
 
+        #
+        # do not respond to a NS for the peer's address
+        #
+        p = (Ether(dst=in6_getnsmac(nsma), src=self.pg0.remote_mac) /
+             IPv6(dst=d,
+                  src=self.pg0._remote_hosts[3].ip6_ll) /
+             ICMPv6ND_NS(tgt=self.pg0._remote_hosts[3].ip6_ll) /
+             ICMPv6NDOptSrcLLAddr(
+                 lladdr=self.pg0.remote_mac))
+
+        self.send_and_assert_no_replies(self.pg0, p)
+
         #
         # we should have learned an ND entry for the peer's link-local
         # but not inserted a route to it in the FIB
@@ -1169,6 +1182,7 @@ class TestICMPv6Echo(VppTestCase):
         for i in self.pg_interfaces:
             i.admin_up()
             i.config_ip6()
+            i.resolve_ndp(link_layer=True)
             i.resolve_ndp()
 
     def tearDown(self):
@@ -1186,39 +1200,34 @@ class TestICMPv6Echo(VppTestCase):
             - Check outgoing ICMPv6 Echo Reply message on pg0 interface.
         """
 
-        icmpv6_id = 0xb
-        icmpv6_seq = 5
-        icmpv6_data = b'\x0a' * 18
-        p_echo_request = (Ether(src=self.pg0.remote_mac,
-                                dst=self.pg0.local_mac) /
-                          IPv6(src=self.pg0.remote_ip6,
-                               dst=self.pg0.local_ip6) /
-                          ICMPv6EchoRequest(
-                              id=icmpv6_id,
-                              seq=icmpv6_seq,
-                              data=icmpv6_data))
-
-        self.pg0.add_stream(p_echo_request)
+        # test both with global and local ipv6 addresses
+        dsts = (self.pg0.local_ip6, self.pg0.local_ip6_ll)
+        id = 0xb
+        seq = 5
+        data = b'\x0a' * 18
+        p = list()
+        for dst in dsts:
+            p.append((Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
+                      IPv6(src=self.pg0.remote_ip6, dst=dst) /
+                      ICMPv6EchoRequest(id=id, seq=seq, data=data)))
+
+        self.pg0.add_stream(p)
         self.pg_enable_capture(self.pg_interfaces)
         self.pg_start()
-
-        rx = self.pg0.get_capture(1)
-        rx = rx[0]
-        ether = rx[Ether]
-        ipv6 = rx[IPv6]
-        icmpv6 = rx[ICMPv6EchoReply]
-
-        self.assertEqual(ether.src, self.pg0.local_mac)
-        self.assertEqual(ether.dst, self.pg0.remote_mac)
-
-        self.assertEqual(ipv6.src, self.pg0.local_ip6)
-        self.assertEqual(ipv6.dst, self.pg0.remote_ip6)
-
-        self.assertEqual(
-            icmp6types[icmpv6.type], "Echo Reply")
-        self.assertEqual(icmpv6.id, icmpv6_id)
-        self.assertEqual(icmpv6.seq, icmpv6_seq)
-        self.assertEqual(icmpv6.data, icmpv6_data)
+        rxs = self.pg0.get_capture(len(dsts))
+
+        for rx, dst in zip(rxs, dsts):
+            ether = rx[Ether]
+            ipv6 = rx[IPv6]
+            icmpv6 = rx[ICMPv6EchoReply]
+            self.assertEqual(ether.src, self.pg0.local_mac)
+            self.assertEqual(ether.dst, self.pg0.remote_mac)
+            self.assertEqual(ipv6.src, dst)
+            self.assertEqual(ipv6.dst, self.pg0.remote_ip6)
+            self.assertEqual(icmp6types[icmpv6.type], "Echo Reply")
+            self.assertEqual(icmpv6.id, id)
+            self.assertEqual(icmpv6.seq, seq)
+            self.assertEqual(icmpv6.data, data)
 
 
 class TestIPv6RD(TestIPv6ND):
@@ -1950,9 +1959,12 @@ class TestIP6LoadBalance(VppTestCase):
 
     def send_and_expect_load_balancing(self, input, pkts, outputs):
         self.pg_send(input, pkts)
+        rxs = []
         for oo in outputs:
             rx = oo._get_capture(1)
             self.assertNotEqual(0, len(rx))
+            rxs.append(rx)
+        return rxs
 
     def send_and_expect_one_itf(self, input, pkts, itf):
         self.pg_send(input, pkts)
@@ -2051,16 +2063,31 @@ class TestIP6LoadBalance(VppTestCase):
         # be guaranteed. But with 64 different packets we do expect some
         # balancing. So instead just ensure there is traffic on each link.
         #
-        self.send_and_expect_load_balancing(self.pg0, port_ip_pkts,
-                                            [self.pg1, self.pg2])
+        rx = self.send_and_expect_load_balancing(self.pg0, port_ip_pkts,
+                                                 [self.pg1, self.pg2])
+        n_ip_pg0 = len(rx[0])
         self.send_and_expect_load_balancing(self.pg0, src_ip_pkts,
                                             [self.pg1, self.pg2])
         self.send_and_expect_load_balancing(self.pg0, port_mpls_pkts,
                                             [self.pg1, self.pg2])
         self.send_and_expect_load_balancing(self.pg0, src_mpls_pkts,
                                             [self.pg1, self.pg2])
-        self.send_and_expect_load_balancing(self.pg0, port_mpls_neos_pkts,
-                                            [self.pg1, self.pg2])
+        rx = self.send_and_expect_load_balancing(self.pg0, port_mpls_neos_pkts,
+                                                 [self.pg1, self.pg2])
+        n_mpls_pg0 = len(rx[0])
+
+        #
+        # change the router ID and expect the distribution changes
+        #
+        self.vapi.set_ip_flow_hash_router_id(router_id=0x11111111)
+
+        rx = self.send_and_expect_load_balancing(self.pg0, port_ip_pkts,
+                                                 [self.pg1, self.pg2])
+        self.assertNotEqual(n_ip_pg0, len(rx[0]))
+
+        rx = self.send_and_expect_load_balancing(self.pg0, src_mpls_pkts,
+                                                 [self.pg1, self.pg2])
+        self.assertNotEqual(n_mpls_pg0, len(rx[0]))
 
         #
         # The packets with Entropy label in should not load-balance,
@@ -2073,8 +2100,8 @@ class TestIP6LoadBalance(VppTestCase):
         #  - now only the stream with differing source address will
         #    load-balance
         #
-        self.vapi.set_ip_flow_hash(vrf_id=0, src=1, dst=1, sport=0, dport=0,
-                                   is_ipv6=1)
+        self.vapi.set_ip_flow_hash(vrf_id=0, src=1, dst=1, proto=1,
+                                   sport=0, dport=0, is_ipv6=1)
 
         self.send_and_expect_load_balancing(self.pg0, src_ip_pkts,
                                             [self.pg1, self.pg2])
@@ -2086,7 +2113,7 @@ class TestIP6LoadBalance(VppTestCase):
         # change the flow hash config back to defaults
         #
         self.vapi.set_ip_flow_hash(vrf_id=0, src=1, dst=1, sport=1, dport=1,
-                                   is_ipv6=1)
+                                   proto=1, is_ipv6=1)
 
         #
         # Recursive prefixes
@@ -2168,20 +2195,10 @@ class TestIP6LoadBalance(VppTestCase):
         self.send_and_expect_one_itf(self.pg0, port_pkts, self.pg3)
 
 
-class TestIP6Punt(VppTestCase):
-    """ IPv6 Punt Police/Redirect """
-
-    @classmethod
-    def setUpClass(cls):
-        super(TestIP6Punt, cls).setUpClass()
-
-    @classmethod
-    def tearDownClass(cls):
-        super(TestIP6Punt, cls).tearDownClass()
-
-    def setUp(self):
-        super(TestIP6Punt, self).setUp()
+class IP6PuntSetup(object):
+    """ Setup for IPv6 Punt Police/Redirect """
 
+    def punt_setup(self):
         self.create_pg_interfaces(range(4))
 
         for i in self.pg_interfaces:
@@ -2189,23 +2206,34 @@ class TestIP6Punt(VppTestCase):
             i.config_ip6()
             i.resolve_ndp()
 
-    def tearDown(self):
-        super(TestIP6Punt, self).tearDown()
+        self.pkt = (Ether(src=self.pg0.remote_mac,
+                          dst=self.pg0.local_mac) /
+                    IPv6(src=self.pg0.remote_ip6,
+                         dst=self.pg0.local_ip6) /
+                    inet6.TCP(sport=1234, dport=1234) /
+                    Raw(b'\xa5' * 100))
+
+    def punt_teardown(self):
         for i in self.pg_interfaces:
             i.unconfig_ip6()
             i.admin_down()
 
+
+class TestIP6Punt(IP6PuntSetup, VppTestCase):
+    """ IPv6 Punt Police/Redirect """
+
+    def setUp(self):
+        super(TestIP6Punt, self).setUp()
+        super(TestIP6Punt, self).punt_setup()
+
+    def tearDown(self):
+        super(TestIP6Punt, self).punt_teardown()
+        super(TestIP6Punt, self).tearDown()
+
     def test_ip_punt(self):
         """ IP6 punt police and redirect """
 
-        p = (Ether(src=self.pg0.remote_mac,
-                   dst=self.pg0.local_mac) /
-             IPv6(src=self.pg0.remote_ip6,
-                  dst=self.pg0.local_ip6) /
-             inet6.TCP(sport=1234, dport=1234) /
-             Raw(b'\xa5' * 100))
-
-        pkts = p * 1025
+        pkts = self.pkt * 1025
 
         #
         # Configure a punt redirect via pg1.
@@ -2236,6 +2264,13 @@ class TestIP6Punt(VppTestCase):
         # but not equal to the number sent, since some were policed
         #
         rx = self.pg1._get_capture(1)
+        stats = policer.get_stats()
+
+        # Single rate policer - expect conform, violate but no exceed
+        self.assertGreater(stats['conform_packets'], 0)
+        self.assertEqual(stats['exceed_packets'], 0)
+        self.assertGreater(stats['violate_packets'], 0)
+
         self.assertGreater(len(rx), 0)
         self.assertLess(len(rx), len(pkts))
 
@@ -2297,6 +2332,119 @@ class TestIP6Punt(VppTestCase):
         self.assertEqual(str(punts[2].punt.nh), '::')
 
 
+class TestIP6PuntHandoff(IP6PuntSetup, VppTestCase):
+    """ IPv6 Punt Police/Redirect """
+    vpp_worker_count = 2
+
+    def setUp(self):
+        super(TestIP6PuntHandoff, self).setUp()
+        super(TestIP6PuntHandoff, self).punt_setup()
+
+    def tearDown(self):
+        super(TestIP6PuntHandoff, self).punt_teardown()
+        super(TestIP6PuntHandoff, self).tearDown()
+
+    def test_ip_punt(self):
+        """ IP6 punt policer thread handoff """
+        pkts = self.pkt * NUM_PKTS
+
+        #
+        # Configure a punt redirect via pg1.
+        #
+        nh_addr = self.pg1.remote_ip6
+        ip_punt_redirect = VppIpPuntRedirect(self, self.pg0.sw_if_index,
+                                             self.pg1.sw_if_index, nh_addr)
+        ip_punt_redirect.add_vpp_config()
+
+        action_tx = PolicerAction(
+            VppEnum.vl_api_sse2_qos_action_type_t.SSE2_QOS_ACTION_API_TRANSMIT,
+            0)
+        #
+        # This policer drops no packets, we are just
+        # testing that they get to the right thread.
+        #
+        policer = VppPolicer(self, "ip6-punt", 400, 0, 10, 0, 1,
+                             0, 0, False, action_tx, action_tx, action_tx)
+        policer.add_vpp_config()
+        ip_punt_policer = VppIpPuntPolicer(self, policer.policer_index,
+                                           is_ip6=True)
+        ip_punt_policer.add_vpp_config()
+
+        for worker in [0, 1]:
+            self.send_and_expect(self.pg0, pkts, self.pg1, worker=worker)
+            if worker == 0:
+                self.logger.debug(self.vapi.cli("show trace max 100"))
+
+        # Combined stats, all threads
+        stats = policer.get_stats()
+
+        # Single rate policer - expect conform, violate but no exceed
+        self.assertGreater(stats['conform_packets'], 0)
+        self.assertEqual(stats['exceed_packets'], 0)
+        self.assertGreater(stats['violate_packets'], 0)
+
+        # Worker 0, should have done all the policing
+        stats0 = policer.get_stats(worker=0)
+        self.assertEqual(stats, stats0)
+
+        # Worker 1, should have handed everything off
+        stats1 = policer.get_stats(worker=1)
+        self.assertEqual(stats1['conform_packets'], 0)
+        self.assertEqual(stats1['exceed_packets'], 0)
+        self.assertEqual(stats1['violate_packets'], 0)
+
+        # Bind the policer to worker 1 and repeat
+        policer.bind_vpp_config(1, True)
+        for worker in [0, 1]:
+            self.send_and_expect(self.pg0, pkts, self.pg1, worker=worker)
+            self.logger.debug(self.vapi.cli("show trace max 100"))
+
+        # The 2 workers should now have policed the same amount
+        stats = policer.get_stats()
+        stats0 = policer.get_stats(worker=0)
+        stats1 = policer.get_stats(worker=1)
+
+        self.assertGreater(stats0['conform_packets'], 0)
+        self.assertEqual(stats0['exceed_packets'], 0)
+        self.assertGreater(stats0['violate_packets'], 0)
+
+        self.assertGreater(stats1['conform_packets'], 0)
+        self.assertEqual(stats1['exceed_packets'], 0)
+        self.assertGreater(stats1['violate_packets'], 0)
+
+        self.assertEqual(stats0['conform_packets'] + stats1['conform_packets'],
+                         stats['conform_packets'])
+
+        self.assertEqual(stats0['violate_packets'] + stats1['violate_packets'],
+                         stats['violate_packets'])
+
+        # Unbind the policer and repeat
+        policer.bind_vpp_config(1, False)
+        for worker in [0, 1]:
+            self.send_and_expect(self.pg0, pkts, self.pg1, worker=worker)
+            self.logger.debug(self.vapi.cli("show trace max 100"))
+
+        # The policer should auto-bind to worker 0 when packets arrive
+        stats = policer.get_stats()
+        stats0new = policer.get_stats(worker=0)
+        stats1new = policer.get_stats(worker=1)
+
+        self.assertGreater(stats0new['conform_packets'],
+                           stats0['conform_packets'])
+        self.assertEqual(stats0new['exceed_packets'], 0)
+        self.assertGreater(stats0new['violate_packets'],
+                           stats0['violate_packets'])
+
+        self.assertEqual(stats1, stats1new)
+
+        #
+        # Clean up
+        #
+        ip_punt_policer.remove_vpp_config()
+        policer.remove_vpp_config()
+        ip_punt_redirect.remove_vpp_config()
+
+
 class TestIPDeag(VppTestCase):
     """ IPv6 Deaggregate Routes """
 
@@ -2856,6 +3004,11 @@ class TestIP6LinkLocal(VppTestCase):
         ll2 = "fe80:2::2"
         ll3 = "fe80:3::3"
 
+        VppNeighbor(self,
+                    self.pg0.sw_if_index,
+                    self.pg0.remote_mac,
+                    ll2).add_vpp_config()
+
         VppIpInterfaceAddress(self, self.pg0, ll1, 128).add_vpp_config()
 
         #
@@ -2903,6 +3056,408 @@ class TestIP6LinkLocal(VppTestCase):
         VppIp6LinkLocalAddress(self, self.pg1, ll3).add_vpp_config()
         self.send_and_expect(self.pg1, [p_echo_request_3], self.pg1)
 
+    def test_ip6_ll_p2p(self):
+        """ IPv6 Link Local P2P (GRE)"""
+
+        self.pg0.config_ip4()
+        self.pg0.resolve_arp()
+        gre_if = VppGreInterface(self,
+                                 self.pg0.local_ip4,
+                                 self.pg0.remote_ip4).add_vpp_config()
+        gre_if.admin_up()
+
+        ll1 = "fe80:1::1"
+        ll2 = "fe80:2::2"
+
+        VppIpInterfaceAddress(self, gre_if, ll1, 128).add_vpp_config()
+
+        self.logger.info(self.vapi.cli("sh ip6-ll gre0 fe80:2::2"))
+
+        p_echo_request_1 = (Ether(src=self.pg0.remote_mac,
+                                  dst=self.pg0.local_mac) /
+                            IP(src=self.pg0.remote_ip4,
+                               dst=self.pg0.local_ip4) /
+                            GRE() /
+                            IPv6(src=ll2, dst=ll1) /
+                            ICMPv6EchoRequest())
+        self.send_and_expect(self.pg0, [p_echo_request_1], self.pg0)
+
+        self.pg0.unconfig_ip4()
+        gre_if.remove_vpp_config()
+
+    def test_ip6_ll_p2mp(self):
+        """ IPv6 Link Local P2MP (GRE)"""
+
+        self.pg0.config_ip4()
+        self.pg0.resolve_arp()
+
+        gre_if = VppGreInterface(
+            self,
+            self.pg0.local_ip4,
+            "0.0.0.0",
+            mode=(VppEnum.vl_api_tunnel_mode_t.
+                  TUNNEL_API_MODE_MP)).add_vpp_config()
+        gre_if.admin_up()
+
+        ll1 = "fe80:1::1"
+        ll2 = "fe80:2::2"
+
+        VppIpInterfaceAddress(self, gre_if, ll1, 128).add_vpp_config()
+
+        p_echo_request_1 = (Ether(src=self.pg0.remote_mac,
+                                  dst=self.pg0.local_mac) /
+                            IP(src=self.pg0.remote_ip4,
+                               dst=self.pg0.local_ip4) /
+                            GRE() /
+                            IPv6(src=ll2, dst=ll1) /
+                            ICMPv6EchoRequest())
+
+        # no route back at this point
+        self.send_and_assert_no_replies(self.pg0, [p_echo_request_1])
+
+        # add teib entry for the peer
+        teib = VppTeib(self, gre_if, ll2, self.pg0.remote_ip4)
+        teib.add_vpp_config()
+
+        self.logger.info(self.vapi.cli("sh ip6-ll gre0 %s" % ll2))
+        self.send_and_expect(self.pg0, [p_echo_request_1], self.pg0)
+
+        # teardown
+        self.pg0.unconfig_ip4()
+
+
+class TestIPv6PathMTU(VppTestCase):
+    """ IPv6 Path MTU """
+
+    def setUp(self):
+        super(TestIPv6PathMTU, self).setUp()
+
+        self.create_pg_interfaces(range(2))
+
+        # setup all interfaces
+        for i in self.pg_interfaces:
+            i.admin_up()
+            i.config_ip6()
+            i.resolve_ndp()
+
+    def tearDown(self):
+        super(TestIPv6PathMTU, self).tearDown()
+        for i in self.pg_interfaces:
+            i.unconfig_ip6()
+            i.admin_down()
+
+    def test_path_mtu_local(self):
+        """ Path MTU for attached neighbour """
+
+        self.vapi.cli("set log class ip level debug")
+        #
+        # The goal here is not test that fragmentation works correctly,
+        # that's done elsewhere, the intent is to ensure that the Path MTU
+        # settings are honoured.
+        #
+
+        #
+        # IPv6 will only frag locally generated packets, so use tunnelled
+        # packets post encap
+        #
+        tun = VppIpIpTunInterface(
+            self,
+            self.pg1,
+            self.pg1.local_ip6,
+            self.pg1.remote_ip6)
+        tun.add_vpp_config()
+        tun.admin_up()
+        tun.config_ip6()
+
+        # set the interface MTU to a reasonable value
+        self.vapi.sw_interface_set_mtu(self.pg1.sw_if_index,
+                                       [2800, 0, 0, 0])
+
+        p_2k = (Ether(dst=self.pg0.local_mac,
+                      src=self.pg0.remote_mac) /
+                IPv6(src=self.pg0.remote_ip6,
+                     dst=tun.remote_ip6) /
+                UDP(sport=1234, dport=5678) /
+                Raw(b'0xa' * 1000))
+        p_1k = (Ether(dst=self.pg0.local_mac,
+                      src=self.pg0.remote_mac) /
+                IPv6(src=self.pg0.remote_ip6,
+                     dst=tun.remote_ip6) /
+                UDP(sport=1234, dport=5678) /
+                Raw(b'0xa' * 600))
+
+        nbr = VppNeighbor(self,
+                          self.pg1.sw_if_index,
+                          self.pg1.remote_mac,
+                          self.pg1.remote_ip6).add_vpp_config()
+
+        # this is now the interface MTU frags
+        self.send_and_expect(self.pg0, [p_2k], self.pg1, n_rx=2)
+        self.send_and_expect(self.pg0, [p_1k], self.pg1)
+
+        # drop the path MTU for this neighbour to below the interface MTU
+        # expect more frags
+        pmtu = VppIpPathMtu(self, self.pg1.remote_ip6, 1300).add_vpp_config()
+
+        # print/format the adj delegate and trackers
+        self.logger.info(self.vapi.cli("sh ip pmtu"))
+        self.logger.info(self.vapi.cli("sh adj 7"))
+
+        self.send_and_expect(self.pg0, [p_2k], self.pg1, n_rx=3)
+        self.send_and_expect(self.pg0, [p_1k], self.pg1, n_rx=2)
+
+        # increase the path MTU to more than the interface
+        # expect to use the interface MTU
+        pmtu.modify(8192)
+
+        self.send_and_expect(self.pg0, [p_2k], self.pg1, n_rx=2)
+        self.send_and_expect(self.pg0, [p_1k], self.pg1)
+
+        # go back to an MTU from the path
+        pmtu.modify(1300)
+
+        self.send_and_expect(self.pg0, [p_2k], self.pg1, n_rx=3)
+        self.send_and_expect(self.pg0, [p_1k], self.pg1, n_rx=2)
+
+        # raise the interface's MTU
+        # should still use that of the path
+        self.vapi.sw_interface_set_mtu(self.pg1.sw_if_index,
+                                       [2000, 0, 0, 0])
+        self.send_and_expect(self.pg0, [p_2k], self.pg1, n_rx=3)
+        self.send_and_expect(self.pg0, [p_1k], self.pg1, n_rx=2)
+
+        # set path high and interface low
+        pmtu.modify(2000)
+        self.vapi.sw_interface_set_mtu(self.pg1.sw_if_index,
+                                       [1300, 0, 0, 0])
+        self.send_and_expect(self.pg0, [p_2k], self.pg1, n_rx=3)
+        self.send_and_expect(self.pg0, [p_1k], self.pg1, n_rx=2)
+
+        # remove the path MTU
+        self.vapi.sw_interface_set_mtu(self.pg1.sw_if_index,
+                                       [2800, 0, 0, 0])
+        pmtu.modify(0)
+
+        self.send_and_expect(self.pg0, [p_2k], self.pg1, n_rx=2)
+        self.send_and_expect(self.pg0, [p_1k], self.pg1)
+
+    def test_path_mtu_remote(self):
+        """ Path MTU for remote neighbour """
+
+        self.vapi.cli("set log class ip level debug")
+        #
+        # The goal here is not test that fragmentation works correctly,
+        # that's done elsewhere, the intent is to ensure that the Path MTU
+        # settings are honoured.
+        #
+        tun_dst = "2001::1"
+
+        route = VppIpRoute(
+            self, tun_dst, 64,
+            [VppRoutePath(self.pg1.remote_ip6,
+                          self.pg1.sw_if_index)]).add_vpp_config()
+
+        #
+        # IPv6 will only frag locally generated packets, so use tunnelled
+        # packets post encap
+        #
+        tun = VppIpIpTunInterface(
+            self,
+            self.pg1,
+            self.pg1.local_ip6,
+            tun_dst)
+        tun.add_vpp_config()
+        tun.admin_up()
+        tun.config_ip6()
+
+        # set the interface MTU to a reasonable value
+        self.vapi.sw_interface_set_mtu(self.pg1.sw_if_index,
+                                       [2800, 0, 0, 0])
+
+        p_2k = (Ether(dst=self.pg0.local_mac,
+                      src=self.pg0.remote_mac) /
+                IPv6(src=self.pg0.remote_ip6,
+                     dst=tun.remote_ip6) /
+                UDP(sport=1234, dport=5678) /
+                Raw(b'0xa' * 1000))
+        p_1k = (Ether(dst=self.pg0.local_mac,
+                      src=self.pg0.remote_mac) /
+                IPv6(src=self.pg0.remote_ip6,
+                     dst=tun.remote_ip6) /
+                UDP(sport=1234, dport=5678) /
+                Raw(b'0xa' * 600))
+
+        nbr = VppNeighbor(self,
+                          self.pg1.sw_if_index,
+                          self.pg1.remote_mac,
+                          self.pg1.remote_ip6).add_vpp_config()
+
+        # this is now the interface MTU frags
+        self.send_and_expect(self.pg0, [p_2k], self.pg1, n_rx=2)
+        self.send_and_expect(self.pg0, [p_1k], self.pg1)
+
+        # drop the path MTU for this neighbour to below the interface MTU
+        # expect more frags
+        pmtu = VppIpPathMtu(self, tun_dst, 1300).add_vpp_config()
+
+        # print/format the fib entry/dpo
+        self.logger.info(self.vapi.cli("sh ip6 fib 2001::1"))
+
+        self.send_and_expect(self.pg0, [p_2k], self.pg1, n_rx=3)
+        self.send_and_expect(self.pg0, [p_1k], self.pg1, n_rx=2)
+
+        # increase the path MTU to more than the interface
+        # expect to use the interface MTU
+        pmtu.modify(8192)
+
+        self.send_and_expect(self.pg0, [p_2k], self.pg1, n_rx=2)
+        self.send_and_expect(self.pg0, [p_1k], self.pg1)
+
+        # go back to an MTU from the path
+        pmtu.modify(1300)
+
+        self.send_and_expect(self.pg0, [p_2k], self.pg1, n_rx=3)
+        self.send_and_expect(self.pg0, [p_1k], self.pg1, n_rx=2)
+
+        # raise the interface's MTU
+        # should still use that of the path
+        self.vapi.sw_interface_set_mtu(self.pg1.sw_if_index,
+                                       [2000, 0, 0, 0])
+        self.send_and_expect(self.pg0, [p_2k], self.pg1, n_rx=3)
+        self.send_and_expect(self.pg0, [p_1k], self.pg1, n_rx=2)
+
+        # turn the tun_dst into an attached neighbour
+        route.modify([VppRoutePath("::",
+                                   self.pg1.sw_if_index)])
+        nbr2 = VppNeighbor(self,
+                           self.pg1.sw_if_index,
+                           self.pg1.remote_mac,
+                           tun_dst).add_vpp_config()
+
+        self.send_and_expect(self.pg0, [p_2k], self.pg1, n_rx=3)
+        self.send_and_expect(self.pg0, [p_1k], self.pg1, n_rx=2)
+
+        # add back to not attached
+        nbr2.remove_vpp_config()
+        route.modify([VppRoutePath(self.pg1.remote_ip6,
+                                   self.pg1.sw_if_index)])
+
+        # set path high and interface low
+        pmtu.modify(2000)
+        self.vapi.sw_interface_set_mtu(self.pg1.sw_if_index,
+                                       [1300, 0, 0, 0])
+        self.send_and_expect(self.pg0, [p_2k], self.pg1, n_rx=3)
+        self.send_and_expect(self.pg0, [p_1k], self.pg1, n_rx=2)
+
+        # remove the path MTU
+        self.vapi.sw_interface_set_mtu(self.pg1.sw_if_index,
+                                       [2800, 0, 0, 0])
+        pmtu.remove_vpp_config()
+        self.send_and_expect(self.pg0, [p_2k], self.pg1, n_rx=2)
+        self.send_and_expect(self.pg0, [p_1k], self.pg1)
+
+
+class TestIPFibSource(VppTestCase):
+    """ IPv6 Table FibSource """
+
+    @classmethod
+    def setUpClass(cls):
+        super(TestIPFibSource, cls).setUpClass()
+
+    @classmethod
+    def tearDownClass(cls):
+        super(TestIPFibSource, cls).tearDownClass()
+
+    def setUp(self):
+        super(TestIPFibSource, self).setUp()
+
+        self.create_pg_interfaces(range(2))
+
+        for i in self.pg_interfaces:
+            i.admin_up()
+            i.config_ip6()
+            i.resolve_arp()
+            i.generate_remote_hosts(2)
+            i.configure_ipv6_neighbors()
+
+    def tearDown(self):
+        super(TestIPFibSource, self).tearDown()
+        for i in self.pg_interfaces:
+            i.admin_down()
+            i.unconfig_ip4()
+
+    def test_fib_source(self):
+        """ IP Table FibSource """
+
+        routes = self.vapi.ip_route_v2_dump(0, True)
+
+        # 2 interfaces (4 routes) + 2 specials + 4 neighbours = 10 routes
+        self.assertEqual(len(routes), 10)
+
+        # dump all the sources in the FIB
+        sources = self.vapi.fib_source_dump()
+        for source in sources:
+            if (source.src.name == "API"):
+                api_source = source.src
+            if (source.src.name == "interface"):
+                intf_source = source.src
+            if (source.src.name == "adjacency"):
+                adj_source = source.src
+            if (source.src.name == "special"):
+                special_source = source.src
+            if (source.src.name == "default-route"):
+                dr_source = source.src
+
+        # dump the individual route types
+        routes = self.vapi.ip_route_v2_dump(0, True, src=adj_source.id)
+        self.assertEqual(len(routes), 4)
+        routes = self.vapi.ip_route_v2_dump(0, True, src=intf_source.id)
+        self.assertEqual(len(routes), 4)
+        routes = self.vapi.ip_route_v2_dump(0, True, src=special_source.id)
+        self.assertEqual(len(routes), 1)
+        routes = self.vapi.ip_route_v2_dump(0, True, src=dr_source.id)
+        self.assertEqual(len(routes), 1)
+
+        # add a new soure that'a better than the API
+        self.vapi.fib_source_add(src={'name': "bgp",
+                                      "priority": api_source.priority - 1})
+
+        # dump all the sources to check our new one is there
+        sources = self.vapi.fib_source_dump()
+
+        for source in sources:
+            if (source.src.name == "bgp"):
+                bgp_source = source.src
+
+        self.assertTrue(bgp_source)
+        self.assertEqual(bgp_source.priority,
+                         api_source.priority - 1)
+
+        # add a route with the default API source
+        r1 = VppIpRouteV2(
+            self, "2001::1", 128,
+            [VppRoutePath(self.pg0.remote_ip6,
+                          self.pg0.sw_if_index)]).add_vpp_config()
+
+        r2 = VppIpRouteV2(self, "2001::1", 128,
+                          [VppRoutePath(self.pg1.remote_ip6,
+                                        self.pg1.sw_if_index)],
+                          src=bgp_source.id).add_vpp_config()
+
+        # ensure the BGP source takes priority
+        p = (Ether(src=self.pg0.remote_mac,
+                   dst=self.pg0.local_mac) /
+             IPv6(src=self.pg0.remote_ip6, dst="2001::1") /
+             inet6.UDP(sport=1234, dport=1234) /
+             Raw(b'\xa5' * 100))
+
+        self.send_and_expect(self.pg0, [p], self.pg1)
+
+        r2.remove_vpp_config()
+        r1.remove_vpp_config()
+
+        self.assertFalse(find_route(self, "2001::1", 128))
+
 
 if __name__ == '__main__':
     unittest.main(testRunner=VppTestRunner)