VPP in host user-mode, part II

- JIRA: CSIT-61

Change-Id: I688b1013a78a1fa3ecdb44c2072f8bd1b46364fb
Signed-off-by: Zdeno Olsovsky <zolsovsk@cisco.com>

5 files changed, 305 insertions, 44 deletions

diff --git a/resources/libraries/robot/l2_traffic.robot b/resources/libraries/robot/l2_traffic.robot
index bb66d9035d..4ec0624c30 100644
--- a/resources/libraries/robot/l2_traffic.robot
+++ b/resources/libraries/robot/l2_traffic.robot
@@ -17,13 +17,33 @@
 | Library | resources.libraries.python.TrafficScriptExecutor
 
 *** Keywords ***
-| Send and receive ICMPv4
-| | [Documentation] | Send ICMPv4 echo request from source interface to destination interface.
-| | [Arguments] | ${tg_node} | ${src_int} | ${dst_int}
+| Send and receive ICMP Packet
+| | [Documentation] | Send ICMPv4/ICMPv6 echo request from source interface to
+| | ...             | destination interface.
+| | ...
+| | ... | *Arguments:*
+| | ...
+| | ... | - {tg_node} - TG node. Type: dictionary
+| | ... | - {src_int} - Source interface. Type: string
+| | ... | - {dst_int} - Destination interface. Type: string
+| | ... | - {src_ip} - Source IP address (Optional). Type: string
+| | ... | - {dst_ip} - Destination IP address (Optional). Type: string
+| | ...
+| | ... | *Return:*
+| | ...
+| | ... | - No value returned
+| | ...
+| | ... | *Example:*
+| | ...
+| | ... | _NOTE:_ Default IP is IPv4
+| | ...
+| | ... | \| Send and receive ICMP Packet \| ${nodes['TG']} \
+| | ... | \| ${tg_to_dut_if1} \| ${tg_to_dut_if2} \|
+| | ...
+| | [Arguments] | ${tg_node} | ${src_int} | ${dst_int} |
+| | ... | ${src_ip}=192.168.100.1 | ${dst_ip}=192.168.100.2
 | | ${src_mac}= | Get Interface Mac | ${tg_node} | ${src_int}
 | | ${dst_mac}= | Get Interface Mac | ${tg_node} | ${dst_int}
-| | ${src_ip}= | Set Variable | 192.168.100.1
-| | ${dst_ip}= | Set Variable | 192.168.100.2
 | | ${args}= | Traffic Script Gen Arg | ${dst_int} | ${src_int} | ${src_mac}
 | |          | ...                    | ${dst_mac} | ${src_ip} | ${dst_ip}
 | | Run Traffic Script On Node | send_ip_icmp.py | ${tg_node} | ${args}
@@ -32,6 +52,56 @@
 | | [Documentation] | Send ICMPv4 echo request from both directions,
 | | ...             | from interface1 to interface2 and
 | | ...             | from interface2 to interface1.
-| | [Arguments] | ${tg_node} | ${int1} | ${int2}
-| | Send and receive ICMPv4 | ${tg_node} | ${int1} | ${int2}
-| | Send and receive ICMPv4 | ${tg_node} | ${int2} | ${int1}
+| | ...
+| | ... | *Arguments:*
+| | ...
+| | ... | - {tg_node} - TG node. Type: dictionary
+| | ... | - {src_int} - Source interface. Type: string
+| | ... | - {dst_int} - Destination interface. Type: string
+| | ... | - {src_ip} - Source IP address (Optional). Type: string
+| | ... | - {dst_ip} - Destination IP address (Optional). Type: string
+| | ...
+| | ... | *Return:*
+| | ...
+| | ... | - No value returned
+| | ...
+| | ... | *Example:*
+| | ...
+| | ... | \| Send and receive ICMPv4 bidirectionally \| ${nodes['TG']} \
+| | ... | \| ${tg_to_dut_if1} \| ${tg_to_dut_if2} \|
+| | ...
+| | [Arguments] | ${tg_node} | ${int1} | ${int2} | ${src_ip}=192.168.100.1 |
+| | ... | ${dst_ip}=192.168.100.2
+| | Send and receive ICMP Packet | ${tg_node} | ${int1} | ${int2} |
+| | ... | ${src_ip} | ${dst_ip}
+| | Send and receive ICMP Packet | ${tg_node} | ${int2} | ${int1} |
+| | ... | ${dst_ip} | ${src_ip}
+
+| Send and receive ICMPv6 bidirectionally
+| | [Documentation] | Send ICMPv6 echo request from both directions,
+| | ...             | from interface1 to interface2 and
+| | ...             | from interface2 to interface1.
+| | ...
+| | ... | *Arguments:*
+| | ...
+| | ... | - {tg_node} - TG node. Type: dictionary
+| | ... | - {src_int} - Source interface. Type: string
+| | ... | - {dst_int} - Destination interface. Type: string
+| | ... | - {src_ip} - Source IP address (Optional). Type: string
+| | ... | - {dst_ip} - Destination IP address (Optional). Type: string
+| | ...
+| | ... | *Return:*
+| | ...
+| | ... | - No value returned
+| | ...
+| | ... | *Example:*
+| | ...
+| | ... | \| Send and receive ICMPv6 bidirectionally \| ${nodes['TG']} \
+| | ... | \| ${tg_to_dut_if1} \| ${tg_to_dut_if2} \|
+| | ...
+| | [Arguments] | ${tg_node} | ${int1} | ${int2} | ${src_ip}=3ffe:63::1 |
+| | ... | ${dst_ip}=3ffe:63::2
+| | Send and receive ICMP Packet | ${tg_node} | ${int1} | ${int2} |
+| | ... | ${src_ip} | ${dst_ip}
+| | Send and receive ICMP Packet | ${tg_node} | ${int2} | ${int1} |
+| | ... | ${dst_ip} | ${src_ip}
\ No newline at end of file
diff --git a/resources/traffic_scripts/send_ip_icmp.py b/resources/traffic_scripts/send_ip_icmp.py
index 711bf3dd25..23e647f43c 100755
--- a/resources/traffic_scripts/send_ip_icmp.py
+++ b/resources/traffic_scripts/send_ip_icmp.py
@@ -12,18 +12,57 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-"""Traffic script that sends an ip icmp packet
-from one interface to the other"""
+"""Traffic script that sends an IP ICMPv4/ICMPv6 packet
+from one interface to the other one."""
 
 import sys
-from resources.libraries.python.PacketVerifier import RxQueue, TxQueue
-from resources.libraries.python.TrafficScriptArg import TrafficScriptArg
+import ipaddress
+
 from scapy.layers.inet import ICMP, IP
 from scapy.all import Ether
+from scapy.layers.inet6 import ICMPv6EchoRequest
+from scapy.layers.inet6 import IPv6
+
+from resources.libraries.python.PacketVerifier import RxQueue, TxQueue
+from resources.libraries.python.TrafficScriptArg import TrafficScriptArg
+
+
+def valid_ipv4(ip):
+    """Check if IP address has the correct IPv4 address format.
+
+    :param ip: IP address.
+    :type ip: str
+    :return: True in case of correct IPv4 address format,
+    otherwise return false.
+    :rtype: bool
+    """
+    try:
+        ipaddress.IPv4Address(unicode(ip))
+        return True
+    except (AttributeError, ipaddress.AddressValueError):
+        return False
+
+
+def valid_ipv6(ip):
+    """Check if IP address has the correct IPv6 address format.
+
+    :param ip: IP address.
+    :type ip: str
+    :return: True in case of correct IPv6 address format,
+    otherwise return false.
+    :rtype: bool
+    """
+    try:
+        ipaddress.IPv6Address(unicode(ip))
+        return True
+    except (AttributeError, ipaddress.AddressValueError):
+        return False
 
 
 def main():
-    """ Send IP icmp packet from one traffic generator interface to the other"""
+    """Send IP ICMPv4/ICMPv6 packet from one traffic generator interface to
+    the other one.
+    """
     args = TrafficScriptArg(['src_mac', 'dst_mac', 'src_ip', 'dst_ip'])
 
     src_mac = args.get_arg('src_mac')
@@ -37,11 +76,23 @@ def main():
     txq = TxQueue(tx_if)
 
     sent_packets = []
-
+    ip_format = ''
+    icmp_format = ''
     # Create empty ip ICMP packet and add padding before sending
-    pkt_raw = Ether(src=src_mac, dst=dst_mac) / \
-              IP(src=src_ip, dst=dst_ip) / \
-              ICMP()
+    if valid_ipv4(src_ip) and valid_ipv4(dst_ip):
+        pkt_raw = (Ether(src=src_mac, dst=dst_mac) /
+                   IP(src=src_ip, dst=dst_ip) /
+                   ICMP())
+        ip_format = 'IP'
+        icmp_format = 'ICMP'
+    elif valid_ipv6(src_ip) and valid_ipv6(dst_ip):
+        pkt_raw = (Ether(src=src_mac, dst=dst_mac) /
+                   IPv6(src=src_ip, dst=dst_ip) /
+                   ICMPv6EchoRequest())
+        ip_format = 'IPv6'
+        icmp_format = 'ICMPv6EchoRequest'
+    else:
+        raise ValueError("IP(s) not in correct format")
 
     # Send created packet on one interface and receive on the other
     sent_packets.append(pkt_raw)
@@ -53,13 +104,13 @@ def main():
     if ether is None:
         raise RuntimeError('ICMP echo Rx timeout')
 
-    if not ether.haslayer(IP):
-        raise RuntimeError(
-            'Not an IP packet received {0}'.format(ether.__repr__()))
+    if not ether.haslayer(ip_format):
+        raise RuntimeError('Not an IP packet received {0}'
+                           .format(ether.__repr__()))
 
-    if not ether.haslayer(ICMP):
-        raise RuntimeError(
-            'Not an ICMP packet received {0}'.format(ether.__repr__()))
+    if not ether.haslayer(icmp_format):
+        raise RuntimeError('Not an ICMP packet received {0}'
+                           .format(ether.__repr__()))
 
     sys.exit(0)
 
diff --git a/tests/suites/bridge_domain/bridge_domain_untagged.robot b/tests/suites/bridge_domain/bridge_domain_untagged.robot
index bada88d47a..cef84c7cd0 100644
--- a/tests/suites/bridge_domain/bridge_domain_untagged.robot
+++ b/tests/suites/bridge_domain/bridge_domain_untagged.robot
@@ -169,10 +169,10 @@
 | | | ...                            | ${tg_node} | ${tg_to_dut2_if1}
 | | | ...                            | ${tg_to_dut2_if2}
 
-| VPP forwards packets through VM via two L2 bridge domains
+| VPP forwards ICMPv4 packets through VM via two L2 bridge domains
 | | [Documentation] | Setup and run VM connected to VPP via Vhost-User
-| | ...             | interfaces and check packet forwarding through VM via two
-| | ...             | L2 bridge domains with learning enabled.
+| | ...             | interfaces and check ICMPv4 packet forwarding through VM
+| | ...             | via two L2 bridge domains with learning enabled.
 | | [Tags] | 3_NODE_DOUBLE_LINK_TOPO | VPP_VM_ENV
 | | Given Path for 2-node testing is set
 | | ... | ${nodes['TG']} | ${nodes['DUT1']} | ${nodes['TG']}
@@ -197,11 +197,39 @@
 | | [Teardown] | Run Keywords | Show Packet Trace on All DUTs | ${nodes}
 | | ...        | AND          | Stop and Clear QEMU | ${dut_node} | ${vm_node}
 
-| VPP forwards packets through VM via two L2 bridge domains with static L2FIB entries
+| VPP forwards ICMPv6 packets through VM via two L2 bridge domains
 | | [Documentation] | Setup and run VM connected to VPP via Vhost-User
-| | ...             | interfaces and check packet forwarding through VM via two
-| | ...             | L2 bridge domains with learning disabled (static L2BFIB
-| | ...             | entries).
+| | ...             | interfaces and check ICMPv6 packet forwarding through VM
+| | ...             | via two L2 bridge domains with learning enabled.
+| | [Tags] | 3_NODE_DOUBLE_LINK_TOPO | VPP_VM_ENV
+| | Given Path for 2-node testing is set
+| | ... | ${nodes['TG']} | ${nodes['DUT1']} | ${nodes['TG']}
+| | And Interfaces in 2-node path are up
+| | When VPP Vhost interfaces for L2BD forwarding are setup | ${dut_node}
+| | ...                                                     | ${sock1}
+| | ...                                                     | ${sock2}
+| | And Bridge domain on DUT node is created | ${dut_node} | ${bd_id1}
+| | And Interface is added to bridge domain | ${dut_node} | ${dut_to_tg_if1}
+| | ...                                     | ${bd_id1}
+| | And Interface is added to bridge domain | ${dut_node} | ${vhost_if1}
+| | ...                                     | ${bd_id1}
+| | And Bridge domain on DUT node is created | ${dut_node} | ${bd_id2}
+| | And Interface is added to bridge domain | ${dut_node} | ${dut_to_tg_if2}
+| | ...                                     | ${bd_id2}
+| | And Interface is added to bridge domain | ${dut_node} | ${vhost_if2}
+| | ...                                     | ${bd_id2}
+| | And VM for Vhost L2BD forwarding is setup | ${dut_node} | ${sock1}
+| | ...                                       | ${sock2}
+| | Then Send and receive ICMPv6 bidirectionally | ${tg_node} | ${tg_to_dut_if1}
+| | ...                                          | ${tg_to_dut_if2}
+| | [Teardown] | Run Keywords | Show Packet Trace on All DUTs | ${nodes}
+| | ...        | AND          | Stop and Clear QEMU | ${dut_node} | ${vm_node}
+
+| VPP forwards ICMPv4 packets through VM via two L2 bridge domains with static L2FIB entries
+| | [Documentation] | Setup and run VM connected to VPP via Vhost-User
+| | ...             | interfaces and check ICMPv4 packet forwarding through VM
+| | ...             | via two L2 bridge domains with learning disabled
+| | ...             | (static L2BFIB entries).
 | | [Tags] | 3_NODE_DOUBLE_LINK_TOPO | VPP_VM_ENV
 | | Given Path for 2-node testing is set
 | | ... | ${nodes['TG']} | ${nodes['DUT1']} | ${nodes['TG']}
@@ -247,3 +275,54 @@
 | | ...                                          | ${tg_to_dut_if2}
 | | [Teardown] | Run Keywords | Show Packet Trace on All DUTs | ${nodes}
 | | ...        | AND          | Stop and Clear QEMU | ${dut_node} | ${vm_node}
+
+| VPP forwards ICMPv6 packets through VM via two L2 bridge domains with static L2FIB entries
+| | [Documentation] | Setup and run VM connected to VPP via Vhost-User
+| | ...             | interfaces and check ICMPv6 packet forwarding through VM
+| | ...             | via two L2 bridge domains with learning disabled
+| | ...             | (static L2BFIB entries).
+| | [Tags] | 3_NODE_DOUBLE_LINK_TOPO | VPP_VM_ENV
+| | Given Path for 2-node testing is set
+| | ... | ${nodes['TG']} | ${nodes['DUT1']} | ${nodes['TG']}
+| | And Interfaces in 2-node path are up
+| | When VPP Vhost interfaces for L2BD forwarding are setup | ${dut_node}
+| | ...                                                     | ${sock1}
+| | ...                                                     | ${sock2}
+| | And Bridge domain on DUT node is created | ${dut_node} | ${bd_id1}
+| | ...                                      | learn=${FALSE}
+| | And Interface is added to bridge domain | ${dut_node} | ${dut_to_tg_if1}
+| | ...                                     | ${bd_id1}
+| | And Interface is added to bridge domain | ${dut_node} | ${vhost_if1}
+| | ...                                     | ${bd_id1}
+| | And Destination port is added to L2FIB on DUT node | ${tg_node}
+| | ...                                                | ${tg_to_dut_if1}
+| | ...                                                | ${dut_node}
+| | ...                                                | ${dut_to_tg_if1}
+| | ...                                                | ${bd_id1}
+| | And Destination port is added to L2FIB on DUT node | ${tg_node}
+| | ...                                                | ${tg_to_dut_if2}
+| | ...                                                | ${dut_node}
+| | ...                                                | ${vhost_if1}
+| | ...                                                | ${bd_id1}
+| | And Bridge domain on DUT node is created | ${dut_node} | ${bd_id2}
+| | ...                                      | learn=${FALSE}
+| | And Interface is added to bridge domain | ${dut_node} | ${dut_to_tg_if2}
+| | ...                                     | ${bd_id2}
+| | And Interface is added to bridge domain | ${dut_node} | ${vhost_if2}
+| | ...                                     | ${bd_id2}
+| | And Destination port is added to L2FIB on DUT node | ${tg_node}
+| | ...                                                | ${tg_to_dut_if2}
+| | ...                                                | ${dut_node}
+| | ...                                                | ${dut_to_tg_if2}
+| | ...                                                | ${bd_id2}
+| | And Destination port is added to L2FIB on DUT node | ${tg_node}
+| | ...                                                | ${tg_to_dut_if1}
+| | ...                                                | ${dut_node}
+| | ...                                                | ${vhost_if2}
+| | ...                                                | ${bd_id2}
+| | And VM for Vhost L2BD forwarding is setup | ${dut_node} | ${sock1}
+| | ...                                       | ${sock2}
+| | Then Send and receive ICMPv6 bidirectionally | ${tg_node} | ${tg_to_dut_if1}
+| | ...                                          | ${tg_to_dut_if2}
+| | [Teardown] | Run Keywords | Show Packet Trace on All DUTs | ${nodes}
+| | ...        | AND          | Stop and Clear QEMU | ${dut_node} | ${vm_node}
diff --git a/tests/suites/l2_xconnect/l2_xconnect_untagged.robot b/tests/suites/l2_xconnect/l2_xconnect_untagged.robot
index a1682d1062..6f3f9b4df1 100644
--- a/tests/suites/l2_xconnect/l2_xconnect_untagged.robot
+++ b/tests/suites/l2_xconnect/l2_xconnect_untagged.robot
@@ -15,24 +15,84 @@
 | Resource | resources/libraries/robot/default.robot
 | Resource | resources/libraries/robot/l2_xconnect.robot
 | Resource | resources/libraries/robot/l2_traffic.robot
+| Resource | resources/libraries/robot/testing_path.robot
 | Resource | resources/libraries/robot/interfaces.robot
+| Resource | resources/libraries/robot/bridge_domain.robot
+| Resource | resources/libraries/robot/qemu.robot
+| Library  | resources.libraries.python.Trace
 | Library | resources.libraries.python.NodePath
 | Force Tags | 3_NODE_SINGLE_LINK_TOPO | HW_ENV | VM_ENV
 | Test Setup | Setup all DUTs before test
 | Suite Setup | Setup all TGs before traffic script
 
+*** Variables ***
+| ${sock1}= | /tmp/sock1
+| ${sock2}= | /tmp/sock2
 
 *** Test Cases ***
-| Vpp forwards packets via L2 xconnect in circular topology
-| | Append Nodes | ${nodes['TG']} | ${nodes['DUT1']} | ${nodes['DUT2']} | ${nodes['TG']}
-| | Compute Path
-| | ${tg_if1} | ${tg}= | Next Interface
-| | ${dut1_if1} | ${dut1}= | Next Interface
-| | ${dut1_if2} | ${dut1}= | Next Interface
-| | ${dut2_if1} | ${dut2}= | Next Interface
-| | ${dut2_if2} | ${dut2}= | Next Interface
-| | ${tg_if2} | ${tg}= | Next Interface
-| | L2 setup xconnect on DUT | ${dut1} | ${dut1_if1} | ${dut1_if2}
-| | L2 setup xconnect on DUT | ${dut2} | ${dut2_if1} | ${dut2_if2}
-| | All Vpp Interfaces Ready Wait | ${nodes}
-| | Send and receive ICMPv4 bidirectionally | ${tg} | ${tg_if1} | ${tg_if2}
+| Vpp forwards ICMPv4 packets via L2 xconnect in circular topology
+| | [Documentation] | Setup single link path with X-connect
+| | ...             | and send ICMPv4 packet.
+| | Given Path for 3-node testing is set
+| | ... | ${nodes['TG']} | ${nodes['DUT1']} | ${nodes['DUT2']} | ${nodes['TG']}
+| | And Interfaces in 3-node path are up
+| | And L2 setup xconnect on DUT
+| | ... | ${dut1_node} | ${dut1_to_tg} | ${dut1_to_dut2}
+| | And L2 setup xconnect on DUT
+| | ... | ${dut2_node} | ${dut2_to_dut1} | ${dut2_to_tg}
+| | When All Vpp Interfaces Ready Wait | ${nodes}
+| | Then Send and receive ICMPv4 bidirectionally
+| | ... | ${tg_node} | ${tg_to_dut1} | ${tg_to_dut2}
+
+| Vpp forwards ICMPv6 packets via L2 xconnect in circular topology
+| | [Documentation] | Setup single link path with X-connect
+| | ...             | and send ICMPv6 packet.
+| | Given Path for 3-node testing is set
+| | ... | ${nodes['TG']} | ${nodes['DUT1']} | ${nodes['DUT2']} | ${nodes['TG']}
+| | And Interfaces in 3-node path are up
+| | And L2 setup xconnect on DUT
+| | ... | ${dut1_node} | ${dut1_to_tg} | ${dut1_to_dut2}
+| | And L2 setup xconnect on DUT
+| | ... | ${dut2_node} | ${dut2_to_dut1} | ${dut2_to_tg}
+| | When All Vpp Interfaces Ready Wait | ${nodes}
+| | Then Send and receive ICMPv6 bidirectionally
+| | ... | ${tg_node} | ${tg_to_dut1} | ${tg_to_dut2}
+
+| VPP forwards ICMPv4 packets through VM via L2 x-connect
+| | [Documentation] | Setup double link path with X-connect via Vhost user
+| | ...             | and send ICMPv4 packet.
+| | [Tags] | 3_NODE_DOUBLE_LINK_TOPO | VPP_VM_ENV
+| | Given Path for 2-node testing is set
+| | ... | ${nodes['TG']} | ${nodes['DUT1']} | ${nodes['TG']}
+| | And Interfaces in 2-node path are up
+| | When VPP Vhost interfaces for L2BD forwarding are setup | ${dut_node}
+| | ...                                                     | ${sock1}
+| | ...                                                     | ${sock2}
+| | And L2 Setup Xconnect on DUT | ${dut_node} | ${dut_to_tg_if1} | ${vhost_if1}
+| | And L2 Setup Xconnect on DUT | ${dut_node} | ${dut_to_tg_if2} | ${vhost_if2}
+| | And VM for Vhost L2BD forwarding is setup | ${dut_node} | ${sock1}
+| | ...                                       | ${sock2}
+| | Then Send and receive ICMPv4 bidirectionally | ${tg_node} | ${tg_to_dut_if1}
+| | ...                                          | ${tg_to_dut_if2}
+| | [Teardown] | Run Keywords | Show Packet Trace on All DUTs | ${nodes}
+| | ...        | AND          | Stop and Clear QEMU | ${dut_node} | ${vm_node}
+
+| VPP forwards ICMPv6 packets through VM via L2 x-connect
+| | [Documentation] | Setup double link path with X-connect via Vhost user
+| | ...             | and send ICMPv6 packet.
+| | [Tags] | 3_NODE_DOUBLE_LINK_TOPO | VPP_VM_ENV
+| | Given Path for 2-node testing is set
+| | ... | ${nodes['TG']} | ${nodes['DUT1']} | ${nodes['TG']}
+| | And Interfaces in 2-node path are up
+| | When VPP Vhost interfaces for L2BD forwarding are setup | ${dut_node}
+| | ...                                                     | ${sock1}
+| | ...                                                     | ${sock2}
+| | And L2 Setup Xconnect on DUT | ${dut_node} | ${dut_to_tg_if1} | ${vhost_if1}
+| | And L2 Setup Xconnect on DUT | ${dut_node} | ${dut_to_tg_if2} | ${vhost_if2}
+| | And VM for Vhost L2BD forwarding is setup | ${dut_node} | ${sock1}
+| | ...                                       | ${sock2}
+| | Then Send and receive ICMPv6 bidirectionally | ${tg_node} | ${tg_to_dut_if1}
+| | ...                                          | ${tg_to_dut_if2}
+| | [Teardown] | Run Keywords | Show Packet Trace on All DUTs | ${nodes}
+| | ...        | AND          | Stop and Clear QEMU | ${dut_node} | ${vm_node}
+
diff --git a/tests/suites/tagging/qinq_l2_xconnect.robot b/tests/suites/tagging/qinq_l2_xconnect.robot
index 856d3accb5..57f61101fd 100644
--- a/tests/suites/tagging/qinq_l2_xconnect.robot
+++ b/tests/suites/tagging/qinq_l2_xconnect.robot
@@ -47,4 +47,5 @@
 | | And Interfaces and VLAN sub-interfaces inter-connected using L2-xconnect
 | | ... | ${dut1_node} | ${dut1_to_tg} | ${subif_index_1}
 | | ... | ${dut2_node} | ${dut2_to_tg} | ${subif_index_2}
-| | Then Send and receive ICMPv4 | ${tg_node} | ${tg_to_dut1} | ${tg_to_dut2}
+| | Then Send and receive ICMP Packet
+| | ... | ${tg_node} | ${tg_to_dut1} | ${tg_to_dut2}