arping is a utility to test the reachability and responsiveness of hosts to ARP. It is effectively like ICMP ping, except using ARP instead. This is beneficial in circumstances where the host has a firewall enabled (every host even firewalled will respond to ARP), or there is no layer 3 connectivity on the IP subnet of the host and hence cannot ping, but do have layer 2 connectivity.
The arping package can be very useful when trying to pick an unused IP address for a subnet to which there is not yet a route or link, but is connected at Layer 2.
Visit the arping website for more information.