Looking for geo-directional DNS service
Bill Woodcock
woody at pch.net
Tue Jan 15 17:00:31 UTC 2008
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
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