When it comes to multi domain or Inter datacenter communication, minimizing the broadcast traffic between the datacenters is an important scaling requirement.
Especially if you are dealing with millions of end hosts, localizing the broadcast traffic is critical to save resources on the network and the end hosts. Resources are bandwidth , CPU , memory and so on.
In this post I will mention how ARP cache is populated in OTV and EVPN technologies and the importance of ARP proxy function. Read more