The BOOTP was first defined in September 1985 in{{Ref RFC|951}} as a replacement for the Reverse Address Resolution Protocol [[RARP]], published in RFC 903 in June 1984.{{Ref RFC|903}} The primary motivation for replacing RARP with BOOTP is that RARP was a [[link layer]] protocol. This made implementation difficult on many server platforms, and required that a server be present on each individual IP [[subnetwork|subnet]]. BOOTP introduced the innovation of relay agents, which forwarded BOOTP packets from the local network using standard IP routing, so that one central BOOTP server could serve hosts on many subnets.<ref>{{citeRef journalRFC|url=http://tools.ietf.org/html/rfc951#section-6 |title=RFC 951 - Bootstrap Protocol |authorrsection=Bill Croft|author2=John Gilmore|date=September 1985|journal=Network Working Group|doi=10.17487/RFC0951 |doi-access=free6}}</ref>
