http://www.rfc-editor.org/rfc/rfc1433.txt
RFC 1433: Directed ARP, J. Garrett, J. Hagan, J. Wong1993-03-01T23:00:00-00:00Directed ARP is a dynamic address resolution procedure that enables hosts and routers to resolve advertised potential next-hop IP addresses on foreign IP networks to their associated link level addresses. This memo defines an Experimental Protocol for the Internet community.