multicloud: after interface_route_table provisioning the OnPrem Gw is unable to reach OnPrem controller

[Senthilnathan Murugappan]

After playing vrouter_interface_route.yml playbook observed that the local onprem compute lost connectivity to the onprem controller and the invalid source pkt count increases in the dropstats counter.

root@5c3s1-node4:~# tcpdump -i bond0 -n -v icmp
tcpdump: listening on bond0, link-type EN10MB (Ethernet), capture size 262144 bytes
14:00:05.156445 IP (tos 0x0, ttl 63, id 48605, offset 0, flags [DF], proto ICMP (1), length 84)
    192.168.1.1 > 192.168.2.1: ICMP echo request, id 7862, seq 1, length 64
14:00:06.163745 IP (tos 0x0, ttl 63, id 48679, offset 0, flags [DF], proto ICMP (1), length 84)
    192.168.1.1 > 192.168.2.1: ICMP echo request, id 7862, seq 2, length 64
14:00:07.171744 IP (tos 0x0, ttl 63, id 48725, offset 0, flags [DF], proto ICMP (1), length 84)
    192.168.1.1 > 192.168.2.1: ICMP echo request, id 7862, seq 3, length 64
14:00:08.179780 IP (tos 0x0, ttl 63, id 48767, offset 0, flags [DF], proto ICMP (1), length 84)
    192.168.1.1 > 192.168.2.1: ICMP echo request, id 7862, seq 4, length 64
^C
4 packets captured
4 packets received by filter
0 packets dropped by kernel
root@5c3s1-node4:~# docker exec -it vrouter_vrouter-agent_1 bash
(vrouter-agent)[root@5c3s1-node4 /]$ dropstats | grep -v ' 0$'
Flow Unusable (Eviction) 1
Invalid NH 2
Duplicated 2
Invalid Source 89

(vrouter-agent)[root@5c3s1-node4 /]$ dropstats | grep -v ' 0$'

Flow Unusable (Eviction) 1
Invalid NH 2
Duplicated 2
Invalid Source 93

FYI Sanju is aware of the issue and took a look at the setup yesterday.

[Sanju Abraham (asanju)]

This is fixed in the vrouter interface route table. When traffic arrives on the GW, it needs to route the pkts via the vhost0 which is also a VMI.

Due to an in-correct / unnecessary prefix in the interface route table, the IP pkts were being dropped. This has been fixed in the PR - https://github.com/Juniper/contrail-multi-cloud/pull/191