DNS requests do not specify who requests the IP address. So think of the problem a CDN has : it has to identify the requesting party's geographical location, ba

DNS requests do not specify who requests the IP address. So think of the problem a CDN has : it has to identify the requesting party's geographical location, based on where the request comes from. If it comes from 8.8.8.8 then you've got no clue. If it comes from an ISPs recursive DNS you can guess : most ISPs have limited geographical reach. If it comes from Telecom Italia's DNS servers, it's either Italy or the middle east (and due to seabone, you will feed them the same entry point to the CDN) When a request comes from Google (or for that matter, another global network like Level3) you have a problem. The request doesn't specify where the client is, and the request will be cached. So what do you do ? Which entrypoint do you feed it ? You're essentially stuck with anycast, and that has it's own problems.