Re: Looking for geo-directional DNS service

[Bill Woodcock <woody () pch net>]

      On Tue, 15 Jan 2008, Hank Nussbacher wrote:
    > The Ultradns (now Neustar) Directional DNS service is based on 
    > statically defined IP responses at each of their 14 sites so there 
    > is no proximity checking done.

Yes, and that's how anycast works: it directs traffic to the 
_topologically nearest_ server.  So as long as there's a DNS server 
topologically near your data server, your users will get the topologically 
nearest of your servers.  Which is why so many content folks _do_ roll 
their own: to ensure fate-sharing between the DNS traffic which 
effectively selects the data server, and the eventual data traffic.

If you're doing things on the Internet, instead of the physical world, 
topological distance is presumably of much greater interest than whatever 
geographic proximity may coincidentally obtain.

                                -Bill