On Mon, 22 Sep 2003, David G. Andersen wrote:
Yes, I hope that UltraDNS implements something like this, if they have not already. It's still not a guarantee that things will get withdrawn -- or be reachable, even if working but not withdrawn -- in case of a problem. That still leaves the DNS for a gTLD at risk for a single point of failure.
The whole problem with only listing two anycast servers is that you leave yourself vulnerable to other kinds of faults. Your upstream ISP fat-fingers "ip route 64.94.110.11 null0" and accidentally blitzes the netblock from which the anycast servers are announced. A router somewhere between customers and the anycast servers stops forwarding traffic, or starts corrupting transit data, without interrupting its route processing. packet filters get misconfigured..
That's a good reason to make sure that you are anycasting from at least two disparate netblocks, isn't it?. :-) /\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\ Patrick Greenwell Asking the wrong questions is the leading cause of wrong answers \/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/