When you enable Distributed Virtual Routing (DvR) on a Controller, it initiates Address Resolution Protocol (ARP) requests for traffic to be routed to unknown destination hosts.
A DvR-enabled Controller learns ARP requests from:
DvR-enabled Leaf nodes (here the Leaf node owns the ARP requests)
its own local UNI ports. Here, the controller owns the ARP requests
other DvR-enabled Controllers
A DvR-enabled Leaf node learns ARP requests from:
its own local UNI ports (here the Leaf node owns the ARP requests)
other DvR-enabled Leaf nodes (that own the ARP requests) and respond to ARP requests on their UNI ports
DvR-enabled Controllers (that own the local UNI ARP requests)
A Controller only distributes ARP entries that are locally learned on its own UNI ports to other DvR-enabled nodes in the domain.