On Feb 25, 2008, at 11:40 AM, sthaug@nethelp.no wrote:
I've only dealt with a handful of the bigger networks, but every transit BGP session I've ever been the customer role on has been filtered by the provider. From memory and in no particular order, that's UUNet, Level3, Digex, Intermedia, Global Crossing, Genuity, Sprint, Above.net, Time Warner, C&W, MCI, XO, Broadwing, and a few smaller ones nobody's likely to have heard of.
There's at least one reasonably big transit provider that does *not* do prefix filtering: TeliaSonera (AS 1299). They *do* perform as-path filtering, but the effectiveness is disputable...
No, the effectiveness is not disputable. It is guaranteed to be sub- optimal. This is not in doubt or question. See, as has been quoted many times, as7007. -- TTFN, patrick