But caching servers are usually setup to load balance. Usually, the servers with the same IP address share an ethernet along with multiple routers. So the packets are switched on essentially a per-packet basis. Or possibly a per-arp basis that alters the MAC-based-forwarding behavior of a switch. This is fairly fine grained load balancing.
This is complete news to me. Of course, I do not run most of the caching name servers on the Internet, so what do I know. Do you?
Would anyone who runs an anycast recursive name server care to supply data points to support or refute Mr. Anderson's assertion?
Our recursive name service, using anycast servers, is setup with 3 name servers at 3 different physical locations, with each server connected to a router at the same physical location. Each server handles two different anycast addresses. There is no per-packet load balancing involved. I can't speak for the rest of the net, of course - but our recursive anycast service has worked well for several years. Steinar Haug, Nethelp consulting, sthaug@nethelp.no