Address Resolution Protocol (ARP) Learning over Tunnels

Layer 3 gateways support learning ARP (Address Resolution Protocol) entries for neighbors reachable through a tunnel. Gateways process ARP requests that ingress the switch from a tunnel, and respond to those requests by sending unicast ARP responses over the tunnel. Similarly, gateways broadcast ARP requests to both physical ports and tunnels and process ARP responses received from a neighbor that is reachable through a tunnel.