----- Original Message ----- From: "Dean Anderson" <[EMAIL PROTECTED]> To: "Paul G" <[EMAIL PROTECTED]> Cc: <[email protected]> Sent: Tuesday, May 03, 2005 8:35 PM Subject: Re: [dnsop] DNS Anycast revisited (fwd)
> On Tue, 3 May 2005, Paul G wrote: > > > > There seems to be no possibility for anycast to be "completely coherent", > > > so ultradns' anycast couldn't be "completely coherent" either. But Vixie > > > mentions it to respond to comments by others about Ultradns' particularly > > > pervasive use of anycast. > > > > it may not be possible to make every service *consistent*, but it is > > perfectly possible to make it coherent (i'm talking about coherency of > > copies of a shared resource). > > This seems to be a trivial interpretation of "coherent". It is assumed > that the copies of DNS _zones_ are kept in sync regardless of whether the > servers are to traditional replicas or to anycasted replicas. No one ever > claimed that zone transfers between the copies would be affected by > anycast. The "in-sync"-ness of the zone data is competely orthogonal to > anycast. Roots are updated via back channels on non-anycast addresses, and > not with AXFR. i'm terribly sorry, but i'm unable to extract any meaning at all from these statements. when i parse them, they make no sense at all (not in terms of being wrong, just not understandable). could you rephrase them? coherency and consistency are well-defined terms in systems engineering. we are talking about dns queries and hence coherency of zone data (the shared resource). i fail to see how this is open to any interpretation at all. i snipped the rest for obvious reasons. -p
