Hi Sriram, > The ASPA verification draft treats the relationship of RS to RS-client as > similar > to that of Provider to Customer. Seems reasonable? The AS of an RS client > includes the RS's AS in its ASPA as a "Provider". >
IMO, the ASPA verification draft regards the relationship between RS and RS-client as "peer-to-peer", maybe my understanding is wrong, I will read the ASPA verification draft again. BR, Shunwan > -----Original Message----- > From: GROW [mailto:grow-boun...@ietf.org] On Behalf Of Sriram, > Kotikalapudi (Fed) > Sent: Thursday, March 10, 2022 11:31 AM > To: Nick Hilliard <n...@foobar.org> > Cc: grow@ietf.org; sidr...@ietf.org > Subject: Re: [GROW] IXP Route Server question > > Nick and all, > > Thank you. What you all shared/discussed is very useful info. > > >Almost all RS's are transparent these days. Usually IXPs go to lengths to > ensure that the RS ASN doesn't appear in the AS path. > > Good to know that. Well, that means there can be an occasional RS that is > non-transparent. When there is a non-transparent RS, could there be big ISPs > (Tier-1, Tier-2) present there as RS-clients? > > The ASPA verification draft treats the relationship of RS to RS-client as > similar > to that of Provider to Customer. Seems reasonable? The AS of an RS client > includes the RS's AS in its ASPA as a "Provider". > > Sriram > > -----Original Message----- > From: Nick Hilliard <n...@foobar.org> > Sent: Tuesday, March 8, 2022 4:28 PM > To: Sriram, Kotikalapudi (Fed) <kotikalapudi.sri...@nist.gov> > Cc: grow@ietf.org; sidr...@ietf.org > Subject: Re: [GROW] IXP Route Server question > > Sriram, Kotikalapudi (Fed) wrote on 08/03/2022 19:36: > > This question has relevance to the ASPA method for route leak > > detection. > > > > Is it possible that an ISP AS A peers with a customer AS C via a > > non-transparent IXP AS B? > > IOW, the AS path in routes propagated by the ISP A for customer C's > > prefixes looks like this: A B C. > > I.e., can the AS of a non-transparent IXP/RS appear in an AS path in > > the middle between an ISP and its customer? > > Almost all RS's are transparent these days. Usually IXPs go to lengths to > ensure that the RS ASN doesn't appear in the AS path. > > Some organisations provide transit over IXPs, but it's a minority thing. > It would be very peculiar if an organisation provided transit over an IXP via > an RS. > > Some organisations provide transit to ASNs over a direct physical connection > while maintain peering with their customer over an IXP port. > Usually this happens by accident, but occasionally it can happen by design. > > The answer to your question is that it would be technically possible, but it > would be so peculiar and stupid that it should be considered a mistake in the > situations where it was intentional. In all other situations, it would be a > leak. > Generally it would be safe to assume that this sort of configuration was in > error. > > Nick > _______________________________________________ > GROW mailing list > GROW@ietf.org > https://www.ietf.org/mailman/listinfo/grow _______________________________________________ GROW mailing list GROW@ietf.org https://www.ietf.org/mailman/listinfo/grow
