Thanks for the inputs about the inter-AS messaging and route-leak prevention techniques between neighboring ASes. Certainly helpful information and also useful for the draft (draft-ietf-idr-route-leak-detection-mitigation). However, my question was focused on "intra-AS" messaging. About conveying from ingress to egress router (within your AS), the info regarding the type of peer from which the route was received at ingress. This info is used at the egress router to avoid leaking a route. Question: Is the "common practice" described in the original message http://mailman.nanog.org/pipermail/nanog/2016-June/086242.html (see the stuff in quotes) sufficient or are there other ways in common use in which network operators convey the said information from ingress to egress router? Sriram