On 31/05/2012 11:23, Daniel Suchy wrote:
In my experience, there're not so many service providers doing that.
Plenty of providers do it. IIWY, I would universally rewrite origin at your ingress points to be the same; otherwise you'll find that providers will merely use it as a means of influencing the bgp best path decision algorithm so that they end up with more of your traffic, and can consequently charge you more. There are many useful ways to build a multi-exit discrimination policy. Using origin is not one of them, in my opinion. The problem is that origin is ranked one place higher than MED. So if you don't rewrite it, you are automatically giving your upstreams an inherent means of strongly influencing the tie-breaking policy. If this were an attribute which actually meant something, then maybe there would be some point in paying attention to it, but it conveys no useful information these days. IOW, it is completely pointless these days and you almost certainly want to work the possibility of any upstream tweaking it. Nick