[dns-operations] Reg Anycast resolver

Leo Vandewoestijne dnsoperations at dns-lab.com
Mon May 23 13:21:42 UTC 2011

> Can anyone share anycast resolver overview document.
> Thanks
> Karthikeyan
There is a zillion documents about anycasting:

One issue I hardly see described is spreading cache over the nodes.
Last year I found bugs both in Google's Public DNS and OpenDNS on that part.
In my anycast I made a proof-of-concept of spreading cache into the memory,
and pull stored replies with correct ttl's.

However from the point of view of efficient GeoDNS trough anycasting, or trough multicasted nameservers 
which locally evaluate BGP tables of remote nodes of a CDN before replieng (done that to), or even
"poor-man geodns", ...in case of a global anycasted resolver; I still doubt how usefull it is if
authoritives send dynamic replies, to anycasted resolvers which spread it to total other regions.
It's sure robust, and for TLD's it's fine, but below that I don't think it's truly that efficient.

I don't think it's a real thread-jack if I ask for your opinions on that.


Leo Vandewoestijne.

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