[ On Thursday, January 25, 2001 at 17:53:12 (-0800), Rusty H. Hodge wrote: ]
Subject: Re: From Microsoft's site
Which would not have suffered such an impact had it been designed correctly, with geographical and topological disparity.
You sure it isn't designed that way? Just because the IPs are on the same /24 doesn't mean anything these days.
It seems in the case of M$'s DNS servers they are all in one place (be it a room, a building, or their campus), and all behind one AS number, with apparently only one router "entity" sitting in front of the whole mess (if you believe what they've been saying has any basis in reality) I haven't looked at how the routing advertisements for that /24 appear out in the rest of the world, beyond what's registered at whois.ra.net, but I doubt they've made separate advertisments for each IP# or some subnets that would separate them, and even if they did I doubt such advertisments coul even make it past the route filters of their peers. By "topological disparity" I meant each server should have radically different IP routing *and* physical connectivity. Even if M$ did have good geographic dispersion with each of their four DNS servers in the four corners of the continental USA and connected back to their campus by some form of private circuits, they've still got effectively one IP routing path to whatever they might use to provide that non-IP connectivity back out to those four corners. I.e. there's still a single point of failure from the perspective of random users on random Internet sites. If there wasn't a single point of failure then the recent events would not have occurred. I just noticed this gem too: Microsoft (NETBLK-MICROSOFT-GLOBAL-NET) One Microsoft Way Redmond, WA 98103 US Netname: MICROSOFT-GLOBAL-NET Netblock: 207.46.0.0 - 207.46.255.255 Coordinator: Microsoft (ZM39-ARIN) noc@microsoft.com 425-936-4200 Domain System inverse mapping provided by: DNS4.CP.MSFT.NET 207.46.138.11 DNS4.CP.MSFT.NET 207.46.138.11 So, how is it that ARIN let them get away with two entries for the same damn server?!?!?!?!? -- Greg A. Woods +1 416 218-0098 VE3TCP <gwoods@acm.org> <robohack!woods> Planix, Inc. <woods@planix.com>; Secrets of the Weird <woods@weird.com>