In multi-interface bare metal compute provision "add default gateway to vhost" fails

[nitishkrishna]

Failure seen:

TASK [contrail/agent : Add default gateway to vhost]
fatal: [10.84.51.12]: FAILED! => {"changed": true, "cmd": "ip route add default via 10.84.51.254 dev vhost0", "delta": "0:00:00.002345", "end": "2017-02-09 14:24:52.613652", "failed": true, "rc": 2, "start": "2017-02-09 14:24:52.611307", "stderr": "RTNETLINK answers: Network is unreachable", "stdout": "", "stdout_lines": [], "warnings": []}

There are two interfaces:
control_data: 5.5.5.12/24
management: 10.84.51.12/24

The task is trying to add default route to vhost interface (not necessary, or necessary only when ip on default gateway network is being moved to vhost0) and this is failing with this error:

root@server12(controller):~# ip route add default via 10.84.51.254 dev vhost0
RTNETLINK answers: Network is unreachable

The 10.84.51.254 gateway will not be reachable from 5.5.5.x network