4. Evaluate ALL Prefixes
Significant Clarification: A router MUST evaluate and set the validation state of all routes in BGP coming from any source (e.g., eBGP, iBGP, or redistribution from static or connected routes), unless specifically configured otherwise by the operator. Otherwise, the operator does not have the ability to drop Invalid routes coming from every potential source and is therefore liable to complaints from neighbors about propagation of Invalid routes. For this reason, [RFC6811] says:
When a BGP speaker receives an UPDATE from a neighbor, it SHOULD perform a lookup as described above for each of the Routes in the UPDATE message. The lookup SHOULD also be applied to routes that are redistributed into BGP from another source, such as another protocol or a locally defined static route.
[RFC6811] goes on to say, "An implementation MAY provide configuration options to control which routes the lookup is applied to."
When redistributing into BGP from any source (e.g., IGP, iBGP, or from static or connected routes), there is no AS_PATH in the input to allow RPKI validation of the originating Autonomous System (AS). In such cases, the router MUST use the AS of the router's BGP configuration. If that is ambiguous because of confederation, AS migration, or other multi-AS configuration, then the router configuration MUST provide a means of specifying the AS to be used on the redistribution, either per redistribution or globally.