Defining traffic in Ostinato 

The following only applies if you are sending unidirectional traffic and don't care about the traffic not returning. 

 

When you don't resolve the MAC layer (ARP), then there's no need to define devices. Just add streams and in "Protocol Data", open "Media Access Protocol" and make destination the next hop mac (ip neigh show) and source as increment to simulate MAC addresses

Now add the IPv4 IPs

and make sure that the number of packets sent is the same as your source amount