From da8aebf2e722f2c441a03b300de71f9143d010a3 Mon Sep 17 00:00:00 2001
From: Juraj Sloboda <jsloboda@cisco.com>
Date: Tue, 23 Feb 2016 15:03:13 +0100
Subject: [PATCH] Modify sweep ping test cases

- Write separate sweep ping test cases for jumbo frames
- Compute sweep ping end size from reported MTU on DUT interface
- Set MTU on TG according to MTU on DUT interface
- Log VPP packet traces on IPv4 and IPv6 tests failure
- Remove VM_ENV tag from sweep ping test cases for jumbo frames

Change-Id: I47aa7977bcff9c4366c67578aef542924a1d055b
Signed-off-by: Juraj Sloboda <jsloboda@cisco.com>
---
 bootstrap.sh                                 |  5 ++--
 resources/libraries/python/InterfaceUtil.py  | 40 +++++++++++++++++++++++++++-
 resources/libraries/python/Trace.py          | 24 +++++++++++++++++
 resources/libraries/python/topology.py       | 24 ++++++++++++++---
 resources/libraries/robot/interfaces.robot   | 15 +++++++++++
 resources/libraries/robot/ipv4.robot         | 14 +++++-----
 resources/libraries/robot/ipv6.robot         | 26 +++++++++---------
 resources/templates/vat/show_trace.vat       |  1 +
 resources/traffic_scripts/ipv4_sweep_ping.py | 12 ++++-----
 tests/suites/ipv4/ipv4_untagged.robot        | 40 +++++++++++++++++++++-------
 tests/suites/ipv6/ipv6_untagged.robot        | 39 ++++++++++++++++++++-------
 tests/suites/vxlan/vxlan_untagged.robot      |  2 +-
 12 files changed, 189 insertions(+), 53 deletions(-)
 create mode 100644 resources/libraries/python/Trace.py
 create mode 100644 resources/templates/vat/show_trace.vat

diff --git a/bootstrap.sh b/bootstrap.sh
index 893a8db3e3..37508668ff 100755
--- a/bootstrap.sh
+++ b/bootstrap.sh
@@ -142,7 +142,7 @@ if [ "$?" -ne "0" ]; then
     exit ${retval}
 fi
 
-if [[ ! "${VIRL_SID}" =~ session-[a-zA-Z0-9]{6} ]]; then
+if [[ ! "${VIRL_SID}" =~ session-[a-zA-Z0-9_]{6} ]]; then
     echo "No VIRL session ID reported."
     exit 127
 fi
@@ -173,9 +173,8 @@ pip install -r requirements.txt
 
 PYTHONPATH=`pwd` pybot -L TRACE \
     -v TOPOLOGY_PATH:topologies/enabled/topology.yaml \
-    --include vm_env \
-    --include 3_NODE_SINGLE_LINK_TOPO \
     --exclude 3_node_double_link_topoNOT3_node_single_link_topo \
+    --include VM_ENV \
     --exclude PERFTEST \
     --noncritical EXPECTED_FAILING \
     tests/
diff --git a/resources/libraries/python/InterfaceUtil.py b/resources/libraries/python/InterfaceUtil.py
index 14473ee4d4..aeb54be86a 100644
--- a/resources/libraries/python/InterfaceUtil.py
+++ b/resources/libraries/python/InterfaceUtil.py
@@ -53,7 +53,45 @@ class InterfaceUtil(object):
             cmd = 'ip link set {} {}'.format(interface, state)
             exec_cmd_no_error(node, cmd, sudo=True)
         else:
-            raise Exception('Unknown NodeType: "{}"'.format(node['type']))
+            raise Exception('Node {} has unknown NodeType: "{}"'.
+                            format(node['host'], node['type']))
+
+    @staticmethod
+    def set_interface_ethernet_mtu(node, interface, mtu):
+        """Set Ethernet MTU for specified interface.
+
+        Function can be used only for TGs.
+
+        :param node: node where the interface is
+        :param interface: interface name
+        :param mtu: MTU to set
+        :type node: dict
+        :type interface: str
+        :type mtu: int
+        :return: nothing
+        """
+        if node['type'] == NodeType.DUT:
+            ValueError('Node {}: Setting Ethernet MTU for interface '
+                       'on DUT nodes not supported', node['host'])
+        elif node['type'] == NodeType.TG:
+            cmd = 'ip link set {} mtu {}'.format(interface, mtu)
+            exec_cmd_no_error(node, cmd, sudo=True)
+        else:
+            raise ValueError('Node {} has unknown NodeType: "{}"'.
+                             format(node['host'], node['type']))
+
+    @staticmethod
+    def set_default_ethernet_mtu_on_all_interfaces_on_node(node):
+        """Set default Ethernet MTU on all interfaces on node.
+
+        Function can be used only for TGs.
+
+        :param node: node where to set default MTU
+        :type node: dict
+        :return: nothing
+        """
+        for ifc in node['interfaces'].values():
+            InterfaceUtil.set_interface_ethernet_mtu(node, ifc['name'], 1500)
 
     @staticmethod
     def vpp_node_interfaces_ready_wait(node, timeout=10):
diff --git a/resources/libraries/python/Trace.py b/resources/libraries/python/Trace.py
new file mode 100644
index 0000000000..8168b909ea
--- /dev/null
+++ b/resources/libraries/python/Trace.py
@@ -0,0 +1,24 @@
+# Copyright (c) 2016 Cisco and/or its affiliates.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at:
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from resources.libraries.python.VatExecutor import VatExecutor
+from resources.libraries.python.topology import NodeType
+
+class Trace(object):
+
+    @staticmethod
+    def show_packet_trace_on_all_duts(nodes):
+        for node in nodes.values():
+            if node['type'] == NodeType.DUT:
+                vat = VatExecutor()
+                vat.execute_script("show_trace.vat", node, json_out=False)
diff --git a/resources/libraries/python/topology.py b/resources/libraries/python/topology.py
index e2c069fc98..75542ad070 100644
--- a/resources/libraries/python/topology.py
+++ b/resources/libraries/python/topology.py
@@ -257,6 +257,7 @@ class Topology(object):
                         format(ifc, if_mac))
             ifc['name'] = interface_dict["interface_name"]
             ifc['vpp_sw_index'] = interface_dict["sw_if_index"]
+            ifc['mtu'] = interface_dict["mtu"]
 
     def update_vpp_interface_data_on_node(self, node):
         """Update vpp generated interface data for a given node in DICT__nodes
@@ -347,13 +348,30 @@ class Topology(object):
         """
         for port in node['interfaces'].values():
             port_name = port.get('name')
-            if port_name is None:
-                continue
             if port_name == interface:
                 return port.get('vpp_sw_index')
 
         return None
 
+    @staticmethod
+    def get_interface_mtu(node, interface):
+        """Get interface MTU.
+
+        Returns physical layer MTU (max. size of Ethernet frame).
+        :param node: Node to get interface MTU on.
+        :param interface: Interface name.
+        :type node: dict
+        :type interface: str
+        :return: MTU or None if not found.
+        :rtype: int
+        """
+        for port in node['interfaces'].values():
+            port_name = port.get('name')
+            if port_name == interface:
+                return port.get('mtu')
+
+        return None
+
     @staticmethod
     def get_interface_mac_by_port_key(node, port_key):
         """Get MAC address for the interface based on port key.
@@ -382,8 +400,6 @@ class Topology(object):
         """
         for port in node['interfaces'].values():
             port_name = port.get('name')
-            if port_name is None:
-                continue
             if port_name == interface:
                 return port.get('mac_address')
 
diff --git a/resources/libraries/robot/interfaces.robot b/resources/libraries/robot/interfaces.robot
index 18c9c0cc81..649ee63253 100644
--- a/resources/libraries/robot/interfaces.robot
+++ b/resources/libraries/robot/interfaces.robot
@@ -11,6 +11,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 *** Settings ***
+| Library | resources.libraries.python.InterfaceUtil
+| Library | resources.libraries.python.NodePath
 | Resource | resources/libraries/robot/vat/interfaces.robot
 
 *** Keywords ***
@@ -18,3 +20,16 @@
 | | VPP reports interfaces through VAT on | ${node}
 #| | VPP reports interfaces through ODL on | ${node}
 #| | VPP reports interfaces through DEBUGCLI on | ${node}
+
+| Setup MTU on TG based on MTU on DUT
+| | [Documentation] | Type of the tg_node must be TG and dut_node must be DUT
+| | [Arguments] | ${tg_node} | ${dut_node}
+| | Append Nodes | ${tg_node} | ${dut_node}
+| | Compute Path
+| | ${tg_port} | ${tg_node}= | First Interface
+| | ${dut_port} | ${dut_node}= | Last Interface
+| | # get physical layer MTU (max. size of Ethernet frame)
+| | ${mtu}= | Get Interface MTU | ${dut_node} | ${dut_port}
+| | # Ethernet MTU is physical layer MTU minus size of Ethernet header and FCS
+| | ${eth_mtu}= | Evaluate | ${mtu} - 14 - 4
+| | Set Interface Ethernet MTU | ${tg_node} | ${tg_port} | ${eth_mtu}
diff --git a/resources/libraries/robot/ipv4.robot b/resources/libraries/robot/ipv4.robot
index 4c76644c54..63a1188332 100644
--- a/resources/libraries/robot/ipv4.robot
+++ b/resources/libraries/robot/ipv4.robot
@@ -75,18 +75,20 @@
 
 | Ipv4 icmp echo sweep
 | | [Documentation] | Type of the src_node must be TG and dst_node must be DUT
-| | [Arguments] | ${src_node} | ${dst_node} | ${src_port} | ${dst_port}
+| | [Arguments] | ${src_node} | ${dst_node} | ${start_size} | ${end_size} | ${step}
+| | Append Nodes | ${src_node} | ${dst_node}
+| | Compute Path
+| | ${src_port} | ${src_node}= | First Interface
+| | ${dst_port} | ${dst_node}= | Last Interface
 | | ${src_ip}= | Get IPv4 address of node "${src_node}" interface "${src_port}" from "${nodes_ipv4_addr}"
 | | ${dst_ip}= | Get IPv4 address of node "${dst_node}" interface "${dst_port}" from "${nodes_ipv4_addr}"
 | | ${src_mac}= | Get Interface Mac | ${src_node} | ${src_port}
 | | ${dst_mac}= | Get Interface Mac | ${dst_node} | ${dst_port}
 | | ${args}= | Traffic Script Gen Arg | ${src_port} | ${src_port} | ${src_mac}
 | |          | ...                    | ${dst_mac} | ${src_ip} | ${dst_ip}
-| # TODO: end_size is currently minimum MTU size for Ethernet minus IPv4 and
-| # ICMP echo header size (1500 - 20 - 8),
-| # MTU info is not in VAT sw_interface_dump output
-| | ${args}= | Set Variable | ${args} --start_size 1 --end_size 1472 --step 1
-| | Run Traffic Script On Node | ipv4_sweep_ping.py | ${src_node} | ${args}
+| | ${args}= | Set Variable
+| | ... | ${args} --start_size ${start_size} --end_size ${end_size} --step ${step}
+| | Run Traffic Script On Node | ipv4_sweep_ping.py | ${src_node} | ${args} | ${20}
 
 | Send ARP request and validate response
 | | [Arguments] | ${tg_node} | ${vpp_node}
diff --git a/resources/libraries/robot/ipv6.robot b/resources/libraries/robot/ipv6.robot
index 78a8eda45a..17ab14274f 100644
--- a/resources/libraries/robot/ipv6.robot
+++ b/resources/libraries/robot/ipv6.robot
@@ -14,12 +14,12 @@
 """IPv6 keywords"""
 
 *** Settings ***
-| Library | resources/libraries/python/IPv6Util.py
-| Library | resources/libraries/python/IPv6Setup.py
-| Library | resources/libraries/python/TrafficScriptExecutor.py
-| Library | resources/libraries/python/NodePath.py
-| Library | resources/libraries/python/Routing.py
-| Library | resources/libraries/python/InterfaceUtil.py
+| Library | resources.libraries.python.IPv6Util
+| Library | resources.libraries.python.IPv6Setup
+| Library | resources.libraries.python.TrafficScriptExecutor
+| Library | resources.libraries.python.NodePath
+| Library | resources.libraries.python.Routing
+| Library | resources.libraries.python.InterfaceUtil
 | Library | resources.libraries.python.topology.Topology
 | Resource | resources/libraries/robot/default.robot
 | Resource | resources/libraries/robot/counters.robot
@@ -42,12 +42,13 @@
 | | Run Traffic Script On Node | icmpv6_echo.py | ${tg_node} | ${args}
 | | Vpp dump stats | ${dst_node}
 | | ${ipv6_counter}= | Vpp get interface ipv6 counter | ${dst_node} | ${dst_port}
-| | Should Be Equal | ${ipv6_counter} | ${2} | #ICMPv6 neighbor advertisment + ICMPv6 echo request
+| | Should Be Equal | ${ipv6_counter} | ${2} | #ICMPv6 neighbor advertisement + ICMPv6 echo request
 
 | Ipv6 icmp echo sweep
 | | [Documentation] | Type of the src_node must be TG and dst_node must be DUT
-| | [Arguments] | ${tg_node} | ${dut_node} | ${nodes_addr}
-| | Append Nodes | ${tg_node} | ${dut_node}
+| | [Arguments] | ${src_node} | ${dst_node} | ${start_size} | ${end_size}
+| | ...         | ${step} | ${nodes_addr}
+| | Append Nodes | ${src_node} | ${dst_node}
 | | Compute Path
 | | ${src_port} | ${src_node}= | First Interface
 | | ${dst_port} | ${dst_node}= | Last Interface
@@ -57,10 +58,9 @@
 | | ${dst_mac}= | Get Interface Mac | ${dst_node} | ${dst_port}
 | | ${args}= | Traffic Script Gen Arg | ${src_port} | ${src_port} | ${src_mac}
 | |          | ...                    | ${dst_mac} | ${src_ip} | ${dst_ip}
-| # TODO: end_size is currently minimum MTU size for IPv6 minus IPv6 and ICMPv6
-| # echo header size, MTU info is not in VAT sw_interface_dump output
-| | ${args}= | Set Variable | ${args} --start_size 0 --end_size 1232 --step 1
-| | Run Traffic Script On Node | ipv6_sweep_ping.py | ${tg_node} | ${args} | ${20}
+| | ${args}= | Set Variable
+| | ...      | ${args} --start_size ${start_size} --end_size ${end_size} --step ${step}
+| | Run Traffic Script On Node | ipv6_sweep_ping.py | ${src_node} | ${args} | ${20}
 
 | Ipv6 tg to dut1 egress
 | | [Documentation] | Send traffic from TG to first DUT egress interface
diff --git a/resources/templates/vat/show_trace.vat b/resources/templates/vat/show_trace.vat
new file mode 100644
index 0000000000..9146d3c89e
--- /dev/null
+++ b/resources/templates/vat/show_trace.vat
@@ -0,0 +1 @@
+exec show trace
diff --git a/resources/traffic_scripts/ipv4_sweep_ping.py b/resources/traffic_scripts/ipv4_sweep_ping.py
index cd332d0391..7f6759724c 100755
--- a/resources/traffic_scripts/ipv4_sweep_ping.py
+++ b/resources/traffic_scripts/ipv4_sweep_ping.py
@@ -20,7 +20,7 @@ import logging
 import os
 logging.getLogger("scapy.runtime").setLevel(logging.ERROR)
 from resources.libraries.python.PacketVerifier import RxQueue, TxQueue,\
-    auto_pad, create_gratuitous_arp_request, checksum_equal
+    create_gratuitous_arp_request, checksum_equal
 from resources.libraries.python.TrafficScriptArg import TrafficScriptArg
 from scapy.layers.inet import IP, ICMP
 from scapy.all import Ether, Raw
@@ -55,10 +55,10 @@ def main():
     # send ICMP echo request with incremented data length and receive ICMP
     # echo reply
     for echo_seq in range(start_size, end_size+1, step):
-        pkt_send = auto_pad(Ether(src=src_mac, dst=dst_mac) /
-                            IP(src=src_ip, dst=dst_ip) /
-                            ICMP(id=echo_id, seq=echo_seq) /
-                            Raw(load=data[0:echo_seq]))
+        pkt_send = (Ether(src=src_mac, dst=dst_mac) /
+                    IP(src=src_ip, dst=dst_ip) /
+                    ICMP(id=echo_id, seq=echo_seq) /
+                    Raw(load=data[0:echo_seq]))
         sent_packets.append(pkt_send)
         txq.send(pkt_send)
 
@@ -97,7 +97,7 @@ def main():
         if 'Raw' in icmpv4:
             load = icmpv4['Raw'].load
         else:
-            load = []
+            load = ""
         if load != data[0:echo_seq]:
             raise RuntimeError(
                 'Received ICMP payload does not match sent payload')
diff --git a/tests/suites/ipv4/ipv4_untagged.robot b/tests/suites/ipv4/ipv4_untagged.robot
index 4f1904e3ba..47fe34acdf 100644
--- a/tests/suites/ipv4/ipv4_untagged.robot
+++ b/tests/suites/ipv4/ipv4_untagged.robot
@@ -14,19 +14,22 @@
 *** Settings ***
 | Library | resources.libraries.python.topology.Topology
 | Library | resources.libraries.python.NodePath
+| Library | resources.libraries.python.Trace
 | Resource | resources/libraries/robot/default.robot
+| Resource | resources/libraries/robot/interfaces.robot
 | Resource | resources/libraries/robot/ipv4.robot
-| Force Tags | HW_ENV | VM_ENV
+| Force Tags | HW_ENV
 | Suite Setup | Run Keywords | Setup all DUTs before test
 | ...         | AND          | Setup all TGs before traffic script
 | ...         | AND          | Update All Interface Data On All Nodes | ${nodes}
 | ...         | AND          | Setup DUT nodes for IPv4 testing
 | Test Setup | Clear interface counters on all vpp nodes in topology | ${nodes}
+| Test Teardown | Run Keyword If Test Failed | Show packet trace on all DUTs | ${nodes}
 
 *** Test Cases ***
 
 | VPP replies to ICMPv4 echo request
-| | [Tags] | 3_NODE_SINGLE_LINK_TOPO
+| | [Tags] | 3_NODE_SINGLE_LINK_TOPO | VM_ENV
 | | Append Nodes | ${nodes['TG']} | ${nodes['DUT1']}
 | | Compute Path
 | | ${src_port} | ${src_node}= | First Interface
@@ -35,6 +38,7 @@
 | | Node "${src_node}" interface "${src_port}" can route to node "${dst_node}" interface "${dst_port}" ${hops} hops away using IPv4
 
 | TG can route to DUT egress interface
+| | [Tags] | 3_NODE_SINGLE_LINK_TOPO | VM_ENV
 | | Append Nodes | ${nodes['TG']} | ${nodes['DUT1']} | ${nodes['DUT2']}
 | | Compute Path
 | | ${src_port} | ${src_node}= | First Interface
@@ -43,7 +47,7 @@
 | | Node "${src_node}" interface "${src_port}" can route to node "${dst_node}" interface "${dst_port}" ${hops} hops away using IPv4
 
 | TG can route to DUT2 through DUT1
-| | [Tags] | 3_NODE_SINGLE_LINK_TOPO
+| | [Tags] | 3_NODE_SINGLE_LINK_TOPO | VM_ENV
 | | Append Nodes | ${nodes['TG']} | ${nodes['DUT1']} | ${nodes['DUT2']}
 | | Compute Path
 | | ${src_port} | ${src_node}= | First Interface
@@ -52,7 +56,7 @@
 | | Node "${src_node}" interface "${src_port}" can route to node "${dst_node}" interface "${dst_port}" ${hops} hops away using IPv4
 
 | TG can route to DUT2 egress interface through DUT1
-| | [Tags] | 3_NODE_SINGLE_LINK_TOPO
+| | [Tags] | 3_NODE_SINGLE_LINK_TOPO | VM_ENV
 | | Append Nodes | ${nodes['TG']} | ${nodes['DUT1']} | ${nodes['DUT2']} | ${nodes['TG']}
 | | Compute Path
 | | ${src_port} | ${src_node}= | First Interface
@@ -61,7 +65,7 @@
 | | Node "${src_node}" interface "${src_port}" can route to node "${dst_node}" interface "${dst_port}" ${hops} hops away using IPv4
 
 | TG can route to TG through DUT1 and DUT2
-| | [Tags] | 3_NODE_SINGLE_LINK_TOPO
+| | [Tags] | 3_NODE_SINGLE_LINK_TOPO | VM_ENV
 | | Append Nodes | ${nodes['TG']} | ${nodes['DUT1']} | ${nodes['DUT2']} | ${nodes['TG']}
 | | Compute Path
 | | ${src_port} | ${src_node}= | First Interface
@@ -81,12 +85,28 @@
 | | ${port} | ${node}= | Next Interface
 | | Check ipv4 interface counter | ${node} | ${port} | ${exp_counter_val}
 
-| VPP can process ICMP echo request from min to max packet size with 1B increment
+| VPP can process ICMP echo request from min to 1500B packet size with 1B increment
+| | [Tags] | 3_NODE_SINGLE_LINK_TOPO | VM_ENV
+| | Ipv4 icmp echo sweep | ${nodes['TG']} | ${nodes['DUT1']} | 0 | 1452 | 1
+
+| VPP can process ICMP echo request from 1500B to max packet size with 10B increment
 | | [Tags] | 3_NODE_SINGLE_LINK_TOPO
-| | Ipv4 icmp echo sweep | ${nodes['TG']} | ${nodes['DUT1']}
-| | ...                  | ${nodes['TG']['interfaces']['port3']['name']}
-| | ...                  | ${nodes['DUT1']['interfaces']['port1']['name']}
+| | [Documentation] | This test case cannot be run reliably on VM_ENV because
+| | ...             | the virtual hosts can be connected using a bridge which
+| | ...             | has its own MTU
+| | [Setup] | Setup MTU on TG based on MTU on DUT | ${nodes['TG']} | ${nodes['DUT1']}
+| | [Teardown] | Set default Ethernet MTU on all interfaces on node | ${nodes['TG']}
+| | Append Nodes | ${nodes['TG']} | ${nodes['DUT1']}
+| | Compute Path
+| | ${dut_port} | ${dut_node}= | Last Interface
+| | ${mtu}= | Get Interface MTU | ${dut_node} | ${dut_port}
+| | # ICMP payload size is frame size minus size of Ehternet header, FCS,
+| | # IPv4 header and ICMP header
+| | ${end_size}= | Evaluate | ${mtu} - 14 - 4 - 20 - 8
+| | Run Keyword If | ${mtu} > 1518
+| | ...            | Ipv4 icmp echo sweep | ${nodes['TG']} | ${nodes['DUT1']}
+| | ...            | 1452 | ${end_size} | 10
 
 | VPP responds to ARP request
-| | [Tags] | 3_NODE_SINGLE_LINK_TOPO
+| | [Tags] | 3_NODE_SINGLE_LINK_TOPO | VM_ENV
 | | Send ARP request and validate response | ${nodes['TG']} | ${nodes['DUT1']}
diff --git a/tests/suites/ipv6/ipv6_untagged.robot b/tests/suites/ipv6/ipv6_untagged.robot
index c9304a23c5..f41e1b5767 100644
--- a/tests/suites/ipv6/ipv6_untagged.robot
+++ b/tests/suites/ipv6/ipv6_untagged.robot
@@ -15,46 +15,67 @@
 
 *** Settings ***
 | Documentation | IPv6 untagged test suite
+| Library | resources.libraries.python.Trace
+| Resource | resources/libraries/robot/interfaces.robot
 | Resource | resources/libraries/robot/ipv6.robot
 | Resource | resources/libraries/robot/counters.robot
 | Resource | resources/libraries/robot/default.robot
 | Variables | resources/libraries/python/IPv6NodesAddr.py | ${nodes}
-| Force Tags | HW_ENV | VM_ENV
+| Force Tags | HW_ENV
 | Suite Setup | Run Keywords | Setup ipv6 to all dut in topology | ${nodes} | ${nodes_ipv6_addr}
 | ...         | AND          | Vpp nodes ra supress link layer | ${nodes}
 | ...         | AND          | Vpp nodes setup ipv6 routing | ${nodes} | ${nodes_ipv6_addr}
 | ...         | AND          | Setup all TGs before traffic script
 | Test Setup | Clear interface counters on all vpp nodes in topology | ${nodes}
+| Test Teardown | Run Keyword If Test Failed | Show packet trace on all DUTs | ${nodes}
 
 *** Test Cases ***
 | VPP replies to ICMPv6 echo request
-| | [Tags] | 3_NODE_SINGLE_LINK_TOPO
+| | [Tags] | 3_NODE_SINGLE_LINK_TOPO | VM_ENV
 | | Ipv6 icmp echo | ${nodes['TG']} | ${nodes['DUT1']} | ${nodes_ipv6_addr}
 
-| VPP can process ICMPv6 echo request from min to max packet size with 1B increment
+| VPP can process ICMPv6 echo request from min to 1500B packet size with 1B increment
+| | [Tags] | 3_NODE_SINGLE_LINK_TOPO | VM_ENV
+| | Ipv6 icmp echo sweep | ${nodes['TG']} | ${nodes['DUT1']} | 0 | 1452 | 1 | ${nodes_ipv6_addr}
+
+| VPP can process ICMPv6 echo request from 1500B to max packet size with 10B increment
 | | [Tags] | 3_NODE_SINGLE_LINK_TOPO
-| | Ipv6 icmp echo sweep | ${nodes['TG']} | ${nodes['DUT1']} | ${nodes_ipv6_addr}
+| | [Documentation] | This test case cannot be run reliably on VM_ENV because
+| | ...             | the virtual hosts can be connected using a bridge which
+| | ...             | has its own MTU
+| | [Setup] | Setup MTU on TG based on MTU on DUT | ${nodes['TG']} | ${nodes['DUT1']}
+| | [Teardown] | Set default Ethernet MTU on all interfaces on node | ${nodes['TG']}
+| | Append Nodes | ${nodes['TG']} | ${nodes['DUT1']}
+| | Compute Path
+| | ${dut_port} | ${dut_node}= | Last Interface
+| | ${mtu}= | Get Interface MTU | ${dut_node} | ${dut_port}
+| | # ICMPv6 payload size is frame size minus size of Ehternet header, FCS,
+| | # IPv6 header and ICMPv6 header
+| | ${end_size}= | Evaluate | ${mtu} - 14 - 4 - 40 - 8
+| | Run Keyword If | ${mtu} > 1518
+| | ...            | Ipv6 icmp echo sweep | ${nodes['TG']} | ${nodes['DUT1']}
+| | ...            | 1452 | ${end_size} | 10 | ${nodes_ipv6_addr}
 
 | TG can route to first DUT egress interface
-| | [Tags] | 3_NODE_SINGLE_LINK_TOPO
+| | [Tags] | 3_NODE_SINGLE_LINK_TOPO | VM_ENV
 | | Ipv6 tg to dut1 egress | ${nodes['TG']} | ${nodes['DUT1']} |
 | | ...                    | ${nodes['DUT2']} | ${nodes_ipv6_addr}
 
 | TG can route to second DUT through first DUT
-| | [Tags] | 3_NODE_SINGLE_LINK_TOPO
+| | [Tags] | 3_NODE_SINGLE_LINK_TOPO | VM_ENV
 | | Ipv6 tg to dut2 via dut1 | ${nodes['TG']} | ${nodes['DUT1']}
 | | ...                      | ${nodes['DUT2']} | ${nodes_ipv6_addr}
 
 | TG can route to second DUT egress interface through first DUT
-| | [Tags] | 3_NODE_SINGLE_LINK_TOPO
+| | [Tags] | 3_NODE_SINGLE_LINK_TOPO | VM_ENV
 | | Ipv6 tg to dut2 egress via dut1 | ${nodes['TG']} | ${nodes['DUT1']}
 | | ...                             | ${nodes['DUT2']} | ${nodes_ipv6_addr}
 
 | TG can route to TG through first and second DUT
-| | [Tags] | 3_NODE_SINGLE_LINK_TOPO
+| | [Tags] | 3_NODE_SINGLE_LINK_TOPO | VM_ENV
 | | Ipv6 tg to tg routed | ${nodes['TG']} | ${nodes['DUT1']} | ${nodes['DUT2']}
 | | ...                  | ${nodes_ipv6_addr}
 
 | VPP replies to IPv6 Neighbor Solicitation
-| | [Tags] | 3_NODE_SINGLE_LINK_TOPO
+| | [Tags] | 3_NODE_SINGLE_LINK_TOPO | VM_ENV
 | | Ipv6 neighbor solicitation | ${nodes['TG']} | ${nodes['DUT1']} | ${nodes_ipv6_addr}
diff --git a/tests/suites/vxlan/vxlan_untagged.robot b/tests/suites/vxlan/vxlan_untagged.robot
index 45d57a902d..0ec977052f 100644
--- a/tests/suites/vxlan/vxlan_untagged.robot
+++ b/tests/suites/vxlan/vxlan_untagged.robot
@@ -16,7 +16,7 @@
 | Resource | resources/libraries/robot/default.robot
 | Resource | resources/libraries/robot/vxlan.robot
 | Resource | resources/libraries/robot/l2_traffic.robot
-| Force Tags | 3_NODE_SINGLE_LINK_TOPO | EXPECTED_FAILING
+| Force Tags | 3_NODE_SINGLE_LINK_TOPO | EXPECTED_FAILING | VM_ENV | HW_ENV
 | Suite Setup | Run Keywords | Setup all DUTs before test
 | ...         | AND          | Setup all TGs before traffic script
 | ...         | AND          | Setup VXLAN tunnel on nodes | ${nodes['TG']}
-- 
2.16.6