On 10/01/2014 07:45, John Levine wrote:
It looks like the sites John talked to are multihomed, NOT doing
routing at their edge (??), and yet wanting to filter? I don't think
that's not clear, from john's description at least.
I can ask (the meeting's not over yet) but I gather that these are
multihomed customers who don't do BGP. The ISP knows what ranges it's
routing to the customer, but it doesn't know what ranges are routed to
the same customer by someone else.
This is not a new problem; we certainly discussed it in the multi6 WG
ten years ago:
http://tools.ietf.org/html/draft-huitema-multi6-ingress-filtering-00
Actually it's one of the reasons that multi6 led to shim6, which mainly
avoids this problem (but is disliked by ISPs for other reasons).
Brian