Ethernet Address Resolution Protocol: Or Converting Network Protocol Addresses to 48.bit Ethernet Address for Transmission on Ethernet Hardware

The implementation of protocol P on a sending host S decides, through protocol P’s routing mechanism, that it wants to transmit to a target host T located some place on a connected piece of 10Mbit Ethernet cable. To actually transmit the Ethernet packet a 48.bit Ethernet address must be generated. The addresses of hosts within protocol P are not always compatible with the corresponding Ethernet address (being different lengths or values). Presented here is a protocol that allows dynamic distribution of the information needed to build tables to translate an address A in protocol P’s address space into a 48.bit Ethernet address. Generalizations have been made which allow the protocol to be used for non-10Mbit Ethernet hardware. Some packet radio networks are examples of such hardware. -------------------------------------------------------------------The protocol proposed here is the result of a great deal of discussion with several other people, most notably J. Noel Chiappa, Yogen Dalal, and James E. Kulp, and helpful comments from David Moon. [The purpose of this RFC is to present a method of Converting Protocol Addresses (e.g., IP addresses) to Local Network Addresses (e.g., Ethernet addresses). This is a issue of general concern in the ARPA Internet community at this time. The method proposed here is presented for your consideration and comment. This is not the specification of a Internet Standard.]