The document discusses Route Origin Validation (ROV) using Resource Public Key Infrastructure (RPKI) as outlined by the Mutually Agreed Norms for Routing Security (MANRS) initiative. It describes how RPKI uses digitally signed certificates and Route Origin Authorizations (ROAs) to validate the origin AS of IP prefixes in BGP routing announcements. The validation status can be used to filter or modify routes. Instructions are provided on setting up various open-source RPKI validators like Routinator, OctoRPKI, and FORT to perform ROV and feed the validated ROA cache into BGP routers.