On 5/30/19 12:54 PM, William Herrin wrote: > It's permissible to announce to your transits with a private AS which > they remove before passing the announcement to the wider Internet. As a > result, the announcement from each provider will have that provider's > origin AS when you see it even though it's actually from a downstream > multihomed customer.
If you were a multi-homed customer the route would still originate from two different AS's, both of your upstream ISP's. If it's the same ISP, then that would not apply. But then again, if it were the same ISP they could filter the more specific and learn downstream customer routes either by IGP, filtering or tagging the /24 with no-export. -- inoc.net!rblayzor XMPP: rblayzor.AT.inoc.net PGP: https://pgp.inoc.net/rblayzor/