All contrail vrouter virtual interfaces are down. Unknown cause

[amandeepsingh91]

The vrouter interfaces page shows all virtual interfaces as down.
I don't know of any cause that resulted in this state, All other interface are up and active.
Debug:
Opencontrail VMs are running and active but unable to ping each other even on same subnet.
All service and interface are up and active except virtual tap interface.
So when i check ping v1 0r ping v2 it shows "network unreachable".