Re: Ingress filtering on transits, peers, and IX ports

[Brandon Martin <lists.nanog () monmotha net>]

On 10/13/20 9:40 PM, Nikolas Geyer wrote:
> Tl;dr - definitely don’t accept your own prefix from the site it originated from, or other sites that have internal 
> connectivity. But also don’t assume that an AS has a full-mesh of internal connectivity behind it and shouldn’t accept 
> its own prefixes for any reason.

While I can understand some reasons why people don't do it, I believe 
the proper thing to do in this case is have multiple ASNs - one for each 
island.

They obviously have distinct routing policy and thus qualify at least 
under ARIN policy AFAIK.  With AS4, we don't have any imminent shortage 
of ASNs and don't need to be particularly stingy about allocating them 
as long as a need is met.
--
Brandon Martin