Geoff and George, I noticed the following in Section 2 of draft-ietf-sidr-roa-validation-05:
A route's "origin AS" is the final element of the route object's AS_PATH attribute. If the final AS_PATH element is an AS Set, indicating that the route is an aggregate, then the origin AS is taken as the AS component of the AGGREGATOR attribute [RFC4271]. In the case where there is an AS Set as the final AS_PATH element and no AGGREGATOR attribute is present then the origin AS is the AS immediately preceding the AS Set in the AS_PATH, and if there is no such AS then the route's origin AS cannot be determined. Granted this is a corner case, but nonetheless I can't see what the reason would be for considering an intermediate AS (albeit the first one contained in an AS_SEQUENCE) to be the origin. I suggest revising as follows: Consider the origin AS to be the contents of the AS_SET if it's a singleton set. Otherwise the origin cannot be determined. Given that it's a corner case, you could also cut right to the chase and just call it undetermined if the path starts (or ends, in your parlance) with an AS_SET, period. --John _______________________________________________ sidr mailing list [email protected] https://www.ietf.org/mailman/listinfo/sidr
