ultradns reachability

Fri Jul 2 15:16:08 UTC 2004

On 2 Jul 2004, at 10:43, Leo Bicknell wrote:

> Note in the later pages what happens to particular servers under
> packet loss.  They all start to show an affinity for a subset of
> the servers.  It's been said that by putting some non-anycasted
> servers in with the anycasted servers what can happen is if the
> anycast has issues many things will "latch on" to the non-anycasted
> servers and not go back even when the anycast is fixed.

In my opinion, the primary purpose of anycast distribution of 
nameservers is reliability of the service as a whole, and not 
performance. Being able to reach a server is much more important than 
whether you can get a reply from a particular server in 10ms or 500ms.

So, I think the issue you mention (which is certainly mention-worthy) 
is a much smaller problem than the apparently observed problem of all 
nameservers in the NS set being unavailable.

Joe