On Thu, 5 May 2011 11:48:31 -0500 "Yaoqing(Joey) Liu" <joey.liuyq@gmail.com> wrote:
Furthermore, that exchange prefixes may often appear to be anycast is not unusual. Those prefixes are often originated by multiple disparate networks who are connected to the exchange.
You mean that many different exchange points are using the same set of prefixes as anycast service in different physical locations?
No, just that you see route announcements for the exchange prefix coming from multiple different origins and paths. So it may appear to be anycast, but in reality would function as if it were multihomed with the route originating from multiple providers. Additionally reachability to addresses within the prefix may differ as a result of the peering relationships from the perspective of the path taken to get there. John