IIJ, Arrcus, & DRL Dragon Research Labs In order to verifiably validate the origin Autonomous Systems and Autonomous System Paths of BGP announcements, routers need a simple but reliable mechanism to receive Resource Public Key Infrastructure (RFC 6480) prefix origin data and router keys from a trusted cache. This document describes a protocol to deliver them. This document describes version 2 of the RPKI-Router protocol. RFC 6810 describes version 0, and RFC 8210 describes version 1. This document updates and replaces RFC 8210.