CSIT-18: Add GRE tunnel libraries and tests. 17/917/17
authorMatej Klotton <mklotton@cisco.com>
Thu, 28 Apr 2016 16:15:49 +0000 (18:15 +0200)
committerMatej Klotton <mklotton@cisco.com>
Mon, 16 May 2016 08:57:29 +0000 (08:57 +0000)
Change-Id: I91ccd65a26ea1782611bccc3badd91e64366a162
Signed-off-by: Matej Klotton <mklotton@cisco.com>
bootstrap.sh
resources/libraries/python/InterfaceUtil.py
resources/libraries/robot/gre.robot [new file with mode: 0644]
resources/templates/vat/create_gre.vat [new file with mode: 0644]
resources/traffic_scripts/send_gre_check_icmp_headers.py [new file with mode: 0755]
resources/traffic_scripts/send_icmp_check_gre_headers.py [new file with mode: 0755]
tests/suites/gre/gre_encapsulation.robot [new file with mode: 0644]

index de6cd37..3f29f98 100755 (executable)
@@ -70,7 +70,7 @@ if [ "${#}" -ne "0" ]; then
     echo ${arr[0]}
 else
     rm -f *.deb
-    VPP_STABLE_VER="1.0.0-437~g8f15e92_amd64"
+    VPP_STABLE_VER="1.0.0-451~g686a5a5_amd64"
     VPP_REPO_URL="https://nexus.fd.io/service/local/repositories/fd.io.dev/content/io/fd/vpp"
     wget -q "${VPP_REPO_URL}/vpp/${VPP_STABLE_VER}/vpp-${VPP_STABLE_VER}.deb" || exit
     wget -q "${VPP_REPO_URL}/vpp-dbg/${VPP_STABLE_VER}/vpp-dbg-${VPP_STABLE_VER}.deb" || exit
index 6790fb7..94250fb 100644 (file)
@@ -572,7 +572,40 @@ class InterfaceUtil(object):
         with VatTerminal(node) as vat:
             vat.vat_terminal_exec_cmd('exec show interfaces')
 
-        return '{}.{}'.format(interface, sub_id), sw_subif_index
+        name = '{}.{}'.format(interface, sub_id)
+        return name, sw_subif_index
+
+    @staticmethod
+    def create_gre_tunnel_interface(node, source_ip, destination_ip):
+        """Create GRE tunnel interface on node.
+
+        :param node: VPP node to add tunnel interface.
+        :param source_ip: Source of the GRE tunnel.
+        :param destination_ip: Destination of the GRE tunnel.
+        :type node: dict
+        :type source_ip: str
+        :type destination_ip: str
+        :return: Name and index of created GRE tunnel interface.
+        :rtype: tuple
+        :raises RuntimeError: If unable to create GRE tunnel interface.
+        """
+        output = VatExecutor.cmd_from_template(node, "create_gre.vat",
+                                               src=source_ip,
+                                               dst=destination_ip)
+        output = output[0]
+
+        if output["retval"] == 0:
+            sw_if_index = output["sw_if_index"]
+
+            vat_executor = VatExecutor()
+            vat_executor.execute_script_json_out("dump_interfaces.vat", node)
+            interface_dump_json = vat_executor.get_script_stdout()
+            name = VatJsonUtil.get_interface_name_from_json(
+                interface_dump_json, sw_if_index)
+            return name, sw_if_index
+        else:
+            raise RuntimeError('Unable to create GRE tunnel on node {}.'
+                               .format(node))
 
     @staticmethod
     def vpp_create_loopback(node):
diff --git a/resources/libraries/robot/gre.robot b/resources/libraries/robot/gre.robot
new file mode 100644 (file)
index 0000000..b2036b8
--- /dev/null
@@ -0,0 +1,123 @@
+# 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.
+
+*** Settings ***
+| Resource | resources/libraries/robot/interfaces.robot
+
+*** Keywords ***
+| GRE tunnel interface is created and up
+| | [Documentation] | Create GRE tunnel interface on defined VPP node and put
+| | ...             | the interface to UP state.
+| | ...
+| | ... | *Arguments:*
+| | ... | - ${dut_node} - DUT node where to create GRE tunnel. Type: dictionary
+| | ... | - ${source_ip_address} - GRE tunnel source IP address. Type: string
+| | ... | - ${destination_ip_address} - GRE tunnel destination IP address.
+| | ... |   Type: string
+| | ...
+| | ... | *Return:*
+| | ... | - ${name} - Name of created GRE tunnel interface. Type: string
+| | ... | - ${index} - SW interface index of created GRE tunnel interface.
+| | ... |   Type: integer
+| | ...
+| | ... | *Example:*
+| | ...
+| | ... | \| ${gre_name} \| ${gre_index}= \
+| | ... | \| GRE tunnel interface is created and up \| ${dut} \
+| | ... | \| 192.0.1.1 \| 192.0.1.2 \|
+| | ...
+| | [Arguments] | ${dut_node} | ${source_ip_address} | ${destination_ip_address}
+| | ${name} | ${index}= | Create GRE Tunnel Interface
+| | | | ... | ${dut_node} | ${source_ip_address} | ${destination_ip_address}
+| | Set Interface State | ${dut_node} | ${index} | up
+| | [Return] | ${name} | ${index}
+
+
+| Send ICMPv4 and check received GRE header
+| | [Documentation] | Send ICMPv4 packet and check if received packed contains
+| | ...             | correct GRE, IP, MAC headers.
+| | ...
+| | ... | *Arguments:*
+| | ... | - ${tg_node} - Node where to run traffic script. Type: dictionary
+| | ... | - ${tx_if} - Interface from where send ICPMv4 packet. Type: string
+| | ... | - ${rx_if} - Interface where to receive GRE packet. Type: string
+| | ... | - ${tx_dst_mac} - Destination MAC address of ICMP packet. Type: string
+| | ... | - ${rx_dst_mac} - Expected destination MAC address of GRE packet.
+| | ... |   Type: string
+| | ... | - ${inner_src_ip} - Source IP address of ICMP packet. Type: string
+| | ... | - ${inner_dst_ip} - Destination IP address of ICMP packet.
+| | ... |   Type: string
+| | ... | - ${outer_src_ip} - Source IP address of GRE packet. Type: string
+| | ... | - ${outer_dst_ip} - Destination IP address of GRE packet.
+| | ... |   Type: string
+| | ...
+| | ... | *Return:*
+| | ... | - No value returned
+| | ...
+| | ... | *Example:*
+| | ...
+| | ... | \| Send ICMPv4 and check received GRE header \
+| | ... | \| ${tg_node} \| ${tg_to_dut_if1} \| ${tg_to_dut_if2} \
+| | ... | \| ${tx_dst_mac} \| ${rx_dst_mac} \| ${net1_host_address} \
+| | ... | \| ${net2_host_address} \| ${dut1_ip_address} \| ${dut2_ip_address} \|
+| | ...
+| | [Arguments] | ${tg_node} | ${tx_if} | ${rx_if}
+| | ...         | ${tx_dst_mac} | ${rx_dst_mac}
+| | ...         | ${inner_src_ip} | ${inner_dst_ip}
+| | ...         | ${outer_src_ip} | ${outer_dst_ip}
+| | ${args}= | Catenate | --tx_if | ${tx_if} | --rx_if | ${rx_if}
+| | | ... | --tx_dst_mac | ${tx_dst_mac} | --rx_dst_mac | ${rx_dst_mac}
+| | | ... | --inner_src_ip | ${inner_src_ip} | --inner_dst_ip | ${inner_dst_ip}
+| | | ... | --outer_src_ip | ${outer_src_ip} | --outer_dst_ip | ${outer_dst_ip}
+| | Run Traffic Script On Node
+| | ... | send_icmp_check_gre_headers.py | ${tg_node} | ${args}
+
+
+| Send GRE and check received ICMPv4 header
+| | [Documentation] | Send ICMPv4 packet and check if received packed contains
+| | ...             | correct GRE, IP, MAC headers.
+| | ...
+| | ... | *Arguments:*
+| | ... | - ${tg_node} - Node where to run traffic script. Type: dictionary
+| | ... | - ${tx_if} - Interface from where send ICPMv4 packet. Type: string
+| | ... | - ${rx_if} - Interface where receive GRE packet. Type: string
+| | ... | - ${tx_dst_mac} - Destination MAC address of GRE packet. Type: string
+| | ... | - ${rx_dst_mac} - Expected destination MAC address of ICMP packet.
+| | ... |   Type: string
+| | ... | - ${inner_src_ip} - Source IP address of ICMP packet. Type: string
+| | ... | - ${inner_dst_ip} - Destination IP address of ICMP packet.
+| | ... |   Type: string
+| | ... | - ${outer_src_ip} - Source IP address of GRE packet. Type: string
+| | ... | - ${outer_dst_ip} - Destination IP address of  GRE packet.
+| | ... |   Type: string
+| | ...
+| | ... | *Return:*
+| | ... | - No value returned
+| | ...
+| | ... | *Example:*
+| | ...
+| | ... | \| Send GRE and check received ICMPv4 header \| ${tg_node} \
+| | ... | \| ${tg_to_dut_if2} \| ${tg_to_dut_if1} \| ${tx_dst_mac} \
+| | ... | \| ${rx_dst_mac} \| ${net2_host_address} \| ${net1_host_address} \
+| | ... | \| ${dut2_ip_address} \| ${dut1_ip_address} \|
+| | ...
+| | [Arguments] | ${tg_node} | ${tx_if} | ${rx_if}
+| | ...         | ${tx_dst_mac} | ${rx_dst_mac}
+| | ...         | ${inner_src_ip} | ${inner_dst_ip}
+| | ...         | ${outer_src_ip} | ${outer_dst_ip}
+| | ${args}= | Catenate | --tx_if | ${tx_if} | --rx_if | ${rx_if}
+| | | ... | --tx_dst_mac | ${tx_dst_mac} | --rx_dst_mac | ${rx_dst_mac}
+| | | ... | --inner_src_ip | ${inner_src_ip} | --inner_dst_ip | ${inner_dst_ip}
+| | | ... | --outer_src_ip | ${outer_src_ip} | --outer_dst_ip | ${outer_dst_ip}
+| | Run Traffic Script On Node
+| | ... | send_gre_check_icmp_headers.py | ${tg_node} | ${args}
diff --git a/resources/templates/vat/create_gre.vat b/resources/templates/vat/create_gre.vat
new file mode 100644 (file)
index 0000000..26cdcfb
--- /dev/null
@@ -0,0 +1 @@
+gre_add_del_tunnel src {src} dst {dst}
diff --git a/resources/traffic_scripts/send_gre_check_icmp_headers.py b/resources/traffic_scripts/send_gre_check_icmp_headers.py
new file mode 100755 (executable)
index 0000000..27eac5d
--- /dev/null
@@ -0,0 +1,86 @@
+#!/usr/bin/env python
+# 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.
+
+"""Traffic script that sends a GRE encapsulated ICMPv4 packet from one
+interface to the other, where is expected ICMPv4 without GRE header.
+"""
+
+import sys
+
+from robot.api import logger
+from scapy.all import Ether
+from scapy.layers.inet import IP_PROTOS
+from scapy.layers.inet import IP
+from scapy.layers.inet import ICMP
+from scapy.layers.l2 import GRE
+
+from resources.libraries.python.PacketVerifier import RxQueue, TxQueue
+from resources.libraries.python.TrafficScriptArg import TrafficScriptArg
+
+
+def main():
+    args = TrafficScriptArg(
+        ['tx_dst_mac', 'rx_dst_mac',
+         'inner_src_ip', 'inner_dst_ip',
+         'outer_src_ip', 'outer_dst_ip'])
+
+    tx_if = args.get_arg('tx_if')
+    rx_if = args.get_arg('rx_if')
+    tx_dst_mac = args.get_arg('tx_dst_mac')
+    rx_dst_mac = args.get_arg('rx_dst_mac')
+    inner_src_ip = args.get_arg('inner_src_ip')
+    inner_dst_ip = args.get_arg('inner_dst_ip')
+    outer_src_ip = args.get_arg('outer_src_ip')
+    outer_dst_ip = args.get_arg('outer_dst_ip')
+
+    rxq = RxQueue(rx_if)
+    txq = TxQueue(tx_if)
+    sent_packets = []
+
+    tx_pkt_raw = Ether(dst=tx_dst_mac) / \
+        IP(src=outer_src_ip, dst=outer_dst_ip) / \
+        GRE() / \
+        IP(src=inner_src_ip, dst=inner_dst_ip) / \
+        ICMP()
+
+    sent_packets.append(tx_pkt_raw)
+    txq.send(tx_pkt_raw)
+    ether = rxq.recv(2)
+
+    if ether is None:
+        raise RuntimeError("ICMP echo Rx timeout")
+
+    # Check RX headers
+    if ether.dst != rx_dst_mac:
+        raise RuntimeError("Matching of received destination MAC unsuccessful.")
+    logger.debug("Comparison of received destination MAC: OK.")
+
+    if ether['IP'].src != inner_src_ip:
+        raise RuntimeError("Matching of received inner source IP unsuccessful.")
+    logger.debug("Comparison of received outer source IP: OK.")
+
+    if ether['IP'].dst != inner_dst_ip:
+        raise RuntimeError(
+            "Matching of received inner destination IP unsuccessful.")
+    logger.debug("Comparison of received outer destination IP: OK.")
+
+    if ether['IP'].proto != IP_PROTOS.icmp:
+        raise RuntimeError("IP protocol is other than ICMP.")
+    logger.debug("Comparison of received ICMP protocol: OK.")
+
+    sys.exit(0)
+
+
+if __name__ == "__main__":
+    main()
diff --git a/resources/traffic_scripts/send_icmp_check_gre_headers.py b/resources/traffic_scripts/send_icmp_check_gre_headers.py
new file mode 100755 (executable)
index 0000000..ccea9f5
--- /dev/null
@@ -0,0 +1,92 @@
+#!/usr/bin/env python
+# 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.
+
+"""Traffic script that sends an ICMPv4 packet from one interface to the other,
+where GRE encapsulated packet is expected.
+"""
+
+import sys
+
+from robot.api import logger
+from scapy.all import Ether
+from scapy.layers.inet import IP_PROTOS
+from scapy.layers.inet import IP
+from scapy.layers.inet import ICMP
+
+from resources.libraries.python.PacketVerifier import RxQueue, TxQueue
+from resources.libraries.python.TrafficScriptArg import TrafficScriptArg
+
+
+def main():
+    args = TrafficScriptArg(
+        ['tx_dst_mac', 'rx_dst_mac',
+         'inner_src_ip', 'inner_dst_ip',
+         'outer_src_ip', 'outer_dst_ip'])
+
+    tx_if = args.get_arg('tx_if')
+    rx_if = args.get_arg('rx_if')
+    tx_dst_mac = args.get_arg('tx_dst_mac')
+    rx_dst_mac = args.get_arg('rx_dst_mac')
+    inner_src_ip = args.get_arg('inner_src_ip')
+    inner_dst_ip = args.get_arg('inner_dst_ip')
+    outer_src_ip = args.get_arg('outer_src_ip')
+    outer_dst_ip = args.get_arg('outer_dst_ip')
+
+    rxq = RxQueue(rx_if)
+    txq = TxQueue(tx_if)
+    sent_packets = []
+
+    tx_pkt_raw = Ether(dst=tx_dst_mac) / \
+        IP(src=inner_src_ip, dst=inner_dst_ip) / \
+        ICMP()
+
+    sent_packets.append(tx_pkt_raw)
+    txq.send(tx_pkt_raw)
+    ether = rxq.recv(2)
+
+    if ether is None:
+        raise RuntimeError("ICMP echo Rx timeout")
+
+    # Check RX headers
+    if ether.dst != rx_dst_mac:
+        raise RuntimeError("Matching of received destination MAC unsuccessful.")
+    logger.debug("Comparison of received destination MAC: OK.")
+
+    if ether['IP'].src != outer_src_ip:
+        raise RuntimeError("Matching of received outer source IP unsuccessful.")
+    logger.debug("Comparison of received outer source IP: OK.")
+
+    if ether['IP'].dst != outer_dst_ip:
+        raise RuntimeError(
+            "Matching of received outer destination IP unsuccessful.")
+    logger.debug("Comparison of received outer destination IP: OK.")
+
+    if ether['IP'].proto != IP_PROTOS.gre:
+        raise RuntimeError("IP protocol is no GRE.")
+    logger.debug("Comparison of received GRE protocol: OK.")
+
+    if ether['IP']['GRE']['IP'].src != inner_src_ip:
+        raise RuntimeError("Matching of received inner source IP unsuccessful.")
+    logger.debug("Comparison of received inner source IP: OK.")
+
+    if ether['IP']['GRE']['IP'].dst != inner_dst_ip:
+        raise RuntimeError(
+            "Matching of received inner destination IP unsuccessful.")
+    logger.debug("Comparison of received inner destination IP: OK.")
+
+    sys.exit(0)
+
+
+if __name__ == "__main__":
+    main()
diff --git a/tests/suites/gre/gre_encapsulation.robot b/tests/suites/gre/gre_encapsulation.robot
new file mode 100644 (file)
index 0000000..1ccd1dc
--- /dev/null
@@ -0,0 +1,128 @@
+# 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.
+
+*** Settings ***
+| Resource | resources/libraries/robot/default.robot
+| Resource | resources/libraries/robot/testing_path.robot
+| Resource | resources/libraries/robot/ipv4.robot
+| Resource | resources/libraries/robot/gre.robot
+| Resource | resources/libraries/robot/traffic.robot
+| Library  | resources.libraries.python.IPUtil
+| Library  | resources.libraries.python.Trace
+| Force Tags | VM_ENV | HW_ENV
+| Test Setup | Run Keywords | Setup all DUTs before test
+| ...        | AND          | Setup all TGs before traffic script
+| Test Teardown | Show Packet Trace on All DUTs | ${nodes}
+| Documentation | *GRE test suite.*
+| ...
+| ... | Test suite uses 2-node topology TG - DUT1 - TG with two links
+| ... | between nodes as well as 3-node topology TG - DUT1 - DUT2 - TG
+| ... | with one link between nodes. Test packets are sent from TG to DUT1.
+| ... | DUT1 encapsulate packet into GRE and send out from other interface.
+| ... | Traffic scripts check received MAC headers, IP headers and GRE headers.
+
+*** Variables ***
+| ${net1_address}= | 192.168.0.0
+| ${net1_host_address}= | 192.168.0.100
+| ${net1_gw_address}= | 192.168.0.1
+| ${net2_address}= | 192.168.2.0
+| ${net2_host_address}= | 192.168.2.100
+| ${net2_gw_address}= | 192.168.2.1
+| ${dut1_ip_address}= | 192.168.1.1
+| ${dut2_ip_address}= | 192.168.1.2
+| ${dut1_gre_ip}= | 172.16.0.1
+| ${dut2_gre_ip}= | 172.16.0.2
+| ${prefix}= | 24
+
+*** Test Cases ***
+| VPP can route IPv4 traffic from GRE tunnel
+| | [Tags] | 3_NODE_SINGLE_LINK_TOPO | 3_NODE_DOUBLE_LINK_TOPO
+| | [Documentation] | Create GRE configuration on 2 DUTs, send IP traffic and
+| | ...             | check IP is not changed.
+| | 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   IP addresses are set on interfaces
+| |       ... | ${dut1_node} | ${dut1_to_dut2} | ${dut1_ip_address} | ${prefix}
+| |       ... | ${dut1_node} | ${dut1_to_tg}   | ${net1_gw_address} | ${prefix}
+| |       ... | ${dut2_node} | ${dut2_to_dut1} | ${dut2_ip_address} | ${prefix}
+| |       ... | ${dut2_node} | ${dut2_to_tg}   | ${net2_gw_address} | ${prefix}
+| | And   VPP IP Probe | ${dut1_node} | ${dut1_to_dut2} | ${dut2_ip_address}
+| | And   VPP IP Probe | ${dut2_node} | ${dut2_to_dut1} | ${dut1_ip_address}
+| | And   Add Arp On Dut | ${dut2_node} | ${dut2_to_tg} | ${net2_host_address}
+| |       ... | ${tg_to_dut2_mac}
+| | ${dut1_gre_interface} | ${dut1_gre_index}=
+| | | ... | When GRE tunnel interface is created and up
+| | |     |      ... | ${dut1_node} | ${dut1_ip_address} | ${dut2_ip_address}
+| | ${dut2_gre_interface} | ${dut2_gre_index}=
+| | | ... | And  GRE tunnel interface is created and up
+| | |     |      ... | ${dut2_node} | ${dut2_ip_address} | ${dut1_ip_address}
+| | And  IP addresses are set on interfaces
+| |      ... | ${dut1_node} | ${dut1_gre_index} | ${dut1_gre_ip} | ${prefix}
+| |      ... | ${dut2_node} | ${dut2_gre_index} | ${dut2_gre_ip} | ${prefix}
+| | And  Vpp Route Add | ${dut1_node} | ${net2_address} | ${prefix}
+| |      ... | ${dut2_gre_ip} | ${dut1_gre_index}
+| | Then Send Packet And Check Headers | ${tg_node}
+| |      ... | ${net1_host_address} | ${net2_host_address}
+| |      ... | ${tg_to_dut1} | ${tg_to_dut1_mac} | ${dut1_to_tg_mac}
+| |      ... | ${tg_to_dut2} | ${dut2_to_tg_mac} | ${tg_to_dut2_mac}
+
+
+| VPP can encapsulate IPv4 traffic in GRE
+| | [Tags] | 3_NODE_DOUBLE_LINK_TOPO
+| | [Documentation] | Create GRE configuration on DUT, send IP traffic and
+| | ...             | check IP is correctly encapsulate into GRE.
+| | Given Path for 2-node testing is set
+| |       ... | ${nodes['TG']} | ${nodes['DUT1']} | ${nodes['TG']}
+| | And   Interfaces in 2-node path are up
+| | And   IP addresses are set on interfaces
+| |       ... | ${dut_node} | ${dut_to_tg_if2} | ${dut1_ip_address} | ${prefix}
+| |       ... | ${dut_node} | ${dut_to_tg_if1} | ${net1_gw_address} | ${prefix}
+| | And  Add Arp On Dut | ${dut_node} | ${dut_to_tg_if2} | ${dut2_ip_address}
+| |      ... | ${tg_to_dut_if2_mac}
+| | ${dut1_gre_interface} | ${dut1_gre_index}=
+| | | ... | When GRE tunnel interface is created and up
+| | |     |      ... | ${dut_node} | ${dut1_ip_address} | ${dut2_ip_address}
+| | And  IP addresses are set on interfaces
+| |      ... | ${dut_node} | ${dut1_gre_index} | ${dut1_gre_ip} | ${prefix}
+| | And  Vpp Route Add | ${dut_node} | ${net2_address} | ${prefix}
+| |      ... | ${dut2_gre_ip} | ${dut1_gre_index}
+| | Then Send ICMPv4 and check received GRE header
+| |      ... | ${tg_node} | ${tg_to_dut_if1} | ${tg_to_dut_if2}
+| |      ... | ${dut_to_tg_if1_mac} | ${tg_to_dut_if2_mac}
+| |      ... | ${net1_host_address} | ${net2_host_address}
+| |      ... | ${dut1_ip_address} | ${dut2_ip_address}
+
+
+| VPP can decapsulate IPv4 traffic in GRE
+| | [Tags] | 3_NODE_DOUBLE_LINK_TOPO
+| | [Documentation] | Create GRE configuration on DUT, send GRE encapsulated
+| | ...             | traffic and  check IP is received without GRE headers.
+| | Given Path for 2-node testing is set
+| |       ... | ${nodes['TG']} | ${nodes['DUT1']} | ${nodes['TG']}
+| | And   Interfaces in 2-node path are up
+| | And   IP addresses are set on interfaces
+| |       ... | ${dut_node} | ${dut_to_tg_if2} | ${dut1_ip_address} | ${prefix}
+| |       ... | ${dut_node} | ${dut_to_tg_if1} | ${net1_gw_address} | ${prefix}
+| | And  Add Arp On Dut | ${dut_node} | ${dut_to_tg_if1} | ${net1_host_address}
+| |      ... | ${tg_to_dut_if1_mac}
+| | ${dut1_gre_interface} | ${dut1_gre_index}=
+| | | ... | When GRE tunnel interface is created and up
+| | |     |      ... | ${dut_node} | ${dut1_ip_address} | ${dut2_ip_address}
+| | And  IP addresses are set on interfaces
+| |      ... | ${dut_node} | ${dut1_gre_index} | ${dut1_gre_ip} | ${prefix}
+| | Then Send GRE and check received ICMPv4 header
+| |      ... | ${tg_node} | ${tg_to_dut_if2} | ${tg_to_dut_if1}
+| |      ... | ${dut_to_tg_if2_mac} | ${tg_to_dut_if1_mac}
+| |      ... | ${net2_host_address} | ${net1_host_address}
+| |      ... | ${dut2_ip_address} | ${dut1_ip_address}