Jeffrey Haas wrote: > On Mon, Dec 18, 2017 at 01:04:03PM +0000, Nick Hilliard wrote: >> It's also common practice for transit providers to use a single ASN >> spanning the globe e.g. 174, 2914, 3356, etc. What you're describing >> here is an aspect of the fact that that as-pathlen has not been a useful >> determinant for the bgp decision engine for many years. > > While somewhat orthogonal to this discussion, path length (and thus > prepending) is about the only useful knob many BGP speakers have to try to > bias incoming traffic. I suspect you mean something a bit different above.
point taken, but I meant for outgoing: it's not useful when you have upstream or peer global asns for outbound traffic. >> Updating rfc4271 would be more productive - and getting IXPs to filter >> ingress bgp feeds by default. > > I hope to be retired before that level of "incremental update" is expected > to work in the Internet at large. :-) Probably hell would freeze over before consensus was reached on a replacement decision engine. > P.S. many providers provide knobs to ignore path length as a consideration. > No spec work is required. yeah, but you know dealing with ixp participants is hard. IXPs are firmly aimed at the mid- to low-end provider market, and often you're dealing with people who just don't understand routing well or who don't have time to twiddle knobs. It's better policy to provide ixp participants with simple guidelines and a well-managed 90% solution rather than spend all day pushing them up the hill. Nick _______________________________________________ GROW mailing list GROW@ietf.org https://www.ietf.org/mailman/listinfo/grow
