Better to use communities instead. On Aug 2, 2012 11:34 AM, "Fredy Kuenzler" <[email protected]> wrote:
> From my observation Level3 has recently changed their routing policy. It > seems that 3356 always prefers customer prefixes of 3549, regardless of the > AS path length. Example (seen from 3356): > > 3549_13030_[Customer1]_[**Customer2] > > is preferred over > > 2914_[Customer1]_[Customer2] > > Considering that both 2914 and 3549 are peers of 3356, and 13030 is a > customer of 3549, 3356 seems to give higher local-pref on the longer > AS-path, likely to increase traffic and revenue of their sister network > 3549. > > Certainly it's common practice to overrule the BGP4 default behaviour, and > widely used by smaller networks. > > Still I'm surprised that it happened obviously rather undetected, at > least, to my knowledge, Level3 did implement it silently and hasn't > published an official statement or customer announcement, which I think, > would have been fair, at least. > > Considering that Level3 3356 and 3549 are by far the largest networks > globally this decision must have a large impact on traffic flows and, of > course money flows. > > Maybe the BGP monitoring experts (aka Renesys et al) can shed some light? > > -- > Fredy Künzler > Init7 / AS13030 > >
