From owner-freebsd-isp Mon Sep 30 14:55:15 2002 Delivered-To: freebsd-isp@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 9EBF337B401 for ; Mon, 30 Sep 2002 14:55:13 -0700 (PDT) Received: from blue.centerone.com (blue.centerone.com [204.133.183.111]) by mx1.FreeBSD.org (Postfix) with ESMTP id 24E3343E42 for ; Mon, 30 Sep 2002 14:55:13 -0700 (PDT) (envelope-from rf-list@centerone.com) Received: from localhost (rf-list@localhost) by blue.centerone.com (8.9.3/8.9.3) with ESMTP id QAA30289 for ; Mon, 30 Sep 2002 16:08:26 -0600 Date: Mon, 30 Sep 2002 16:08:26 -0600 (MDT) From: Ralph Forsythe Cc: freebsd-isp@FreeBSD.ORG Subject: Re: Multihoming alternatives In-Reply-To: <6430B9FF-D4A7-11D6-A6AC-000A27D85A7E@mac.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-isp@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org On Mon, 30 Sep 2002, Chuck Swiger wrote: > [ ... ] > > Assuming that you already have a T1 from one provider, get a second T1 > > from another provider, then get a full /24 from one of them, which any > > Tier-1 provider will do without question when you mention that you > > intend to run BGP-4 with 2 separate providers. > > Yes, although a /24 isn't guaranteed to be globally routable. Yes, quite the opposite, it's all but guaranteed to NOT be globally routable. AFAIK there is a big push for route consolidation, and many larger route points will not even pass a route entry for something that small. If you could find two providers that can peer through the same upstream and pass that I think it would work though, right? (Assuming they have other peer points, otherwise it'd just be a single point of failure further down the line.) > > There's been a number of discussions on this topic before, and I believe > > that the general concensus is that using a DNS round-robin is not even > > close to an ideal redundancy solution and should be avoided at all cost. > > Paul was asking about methods which did not involve BGP. DNS round-robin > is free, so I'd say "it should be avoided if you're willing to pay for > something better". DNS round-robin isn't a great redundancy scenario (i.e. if DNS stays up but has no idea that one of it's hosts out of two are down, only 50% of requests go to the good server), but it does provide for a poor-man's load balancing solution. I also saw a script once somewhere that would monitor servers (probably just a ping) and auto-update the round robin in the event of a failure. Of course the best way to go is a true load balancer, so some poor user's PC isn't caching a downed IP even though DNS is reporting something else. But therein lies the cost issue again. Got to pay to play, ultimately. True balanced redundancy is not cheap, when done right. - Ralph To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-isp" in the body of the message