North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: ultradns reachability
In a message written on Fri, Jul 02, 2004 at 10:22:09AM -0400, Joe Abley wrote: > This leaves the anycast servers providing all the optimisation that > they are good for (local nameserver in toplogically distant networks; > distributed DDoS traffic sink; reduced transaction RTT) and provides a > fall-back in case of effective reachability problems for the anycast > nameservers. > > This is so trivial, I continue to be amazed that PIR hasn't done it. I talked to Rodney about this a long time ago, as well as a few other people. What in practice seems simple is complicated by some of the software that is out there. See: http://www.nanog.org/mtg-0310/pdf/wessels.pdf 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. How serious this is for something like .org I have no idea, but it's clear all the software has issues, and until they are fixed I don't think this is just a slam dunk. -- Leo Bicknell - [email protected] - CCIE 3440 PGP keys at http://www.ufp.org/~bicknell/ Read TMBG List - [email protected], www.tmbg.org Attachment:
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