[dns-operations] TCP anycast was Re: DNS query logging

Chris Adams cmadams at hiwaay.net
Thu Mar 17 18:16:38 UTC 2011


Once upon a time, Rick Jones <rick.jones2 at hp.com> said:
> So, what is the frequency of "shifts" for anycast anyway?  The NTP folks
> (as expressed in posts to comp.protocols.time.ntp) seem to not be
> terribly fond of it even for UDP-based time synchronization.  Those
> folks are generally pretty detail-oriented so I'd not necessarily
> suspect they would be easily given to fear uncertainty and doubt, but
> cannot rule it out entirely.

Anycast isn't a good idea for NTP because delay, offset, and jitter for
a particular server go into the calculations, and anycast changes those
without NTP having a way to throw out previous calculations.  You're
better off just listing all the available servers for NTP.

-- 
Chris Adams <cmadams at hiwaay.net>
Systems and Network Administrator - HiWAAY Internet Services
I don't speak for anybody but myself - that's enough trouble.


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