Icmp traffic not mirrored to analyzer vm

[wenqing liang]

Seen in r3.1-87 mitaka, icmp pkts were not sent to the analyzer vm when mirroring was configured. (logs uploaded to /cs-shared/bugs/)

- contrail-ha cluster with 2 computes (server4 and server5)
- src compute server4 -> dst compute server5 => analyzer compute server5
- Created 3 VNs ctest-vn1-17817634/ctest-vn3-48853594/ and verified them in api server and on all control nodes and in opserver
- Attached policy ctest-vn1_vn2_pass-78699237 to vn ctest-vn1-17817634/ctest-vn2-72799154
- Attached policy ctest-vn1_vn3_pass-83408443 to vn ctest-vn1-17817634/ctest-vn3-48853594
- Attached policy ctest-vn2_vn3_pass-49848103 to vn ctest-vn2-72799154/ctest-vn3-48853594
- created VM ctest-src_vm-71638443 on server4 and ctest-dst_vm-04711917 on server5 and verified them in api and opservers
- created VM ctest-analyzer_vm-17335459 on server5
- tap interface default-domain:ctest-TestIntfMirror-19806505:49cb3d52-0e86-4dd8-89b6-7cd597b3fe87 of vm 12fe7815-db8c-4037-9156-a08e8b11e38d is present in vrouter server4 uve
- Validated routes of VM ctest-dst_vm-04711917 in all vrouters
- tap interface default-domain:ctest-TestIntfMirror-19806505:13fff64c-1853-48ad-82f6-758553c7be67 of vm d4c47587-ba0a-4d76-bc5d-b872c754e272 is present in vrouter server5 uve
- tap interface default-domain:ctest-TestIntfMirror-19806505:d06f2dd5-c064-434a-9baf-4bc9079b915a of vm 8d04f111-8681-4771-93b3-be399f8c1a0b is present in vrouter server5 uve
- Compute/VM: SRC: server4 / 186.232.40.3, -> DST: server5 / 82.247.190.3 => ANALYZER: server5 / 4.72.227.3
- Started tcpdump to capture the mirrored packets.
- Ping to IP 82.247.190.3 from VM ctest-src_vm-71638443 passed
- Ping from 186.232.40.3 to 82.247.190.3 executed with c=5, expected mirrored packets 5 Ingress,5 Egress count = 10
- Waited for the tcpdump write to complete but no ICMP packets mirrored to the analyzer VM ctest-analyzer_vm-17335459 though 10 packets were expected

env.roledefs = {
        'control' : [ host3, host4, host5 ],
        'all' : [ host1, host2, host3, host4, host5 ],
        'compute' : [ host1, host2 ],
        'webui' : [ host3, host4, host5 ],
        'cfgm' : [ host3, host4, host5 ],
        'openstack' : [ host3, host4, host5 ],
        'database' : [ host3, host4, host5 ],
        'collector' : [ host3, host4, host5 ],
        'build' : [ host_build ]
}

env.all_server_fips = {u'server4': '10.87.118.45', u'server5': '10.87.118.42', u'server1': '10.87.118.43', u'server2': '10.87.118.44', u'server3': '10.87.118.41'}