we have a three node topology in openstack, vpps are configured by ODL via honeycomb:
one vpp on controller with tap port connected to dhcp server
two vpps, each on one compute, one vhost-user port connected to one vm on each

there's a full vxlan tunnel mesh between the three nodes
there's one bridge domain, all ports are in that bridge domain

there's only dhcp traffic in the whole system - the traffic should start flowing when the vm/vhost-user port is created

qemu is creating the vhost-user port and vpp connects to it (i.e. qemu is server and vpp is client)

api trace custom-dump should provide the configuration sequence