From owner-freebsd-questions@FreeBSD.ORG Wed Dec 28 13:36:19 2011 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id A9D5C1065675 for ; Wed, 28 Dec 2011 13:36:19 +0000 (UTC) (envelope-from ml@my.gd) Received: from mail-lpp01m010-f54.google.com (mail-lpp01m010-f54.google.com [209.85.215.54]) by mx1.freebsd.org (Postfix) with ESMTP id 2D65F8FC14 for ; Wed, 28 Dec 2011 13:36:18 +0000 (UTC) Received: by lahl5 with SMTP id l5so6773014lah.13 for ; Wed, 28 Dec 2011 05:36:17 -0800 (PST) Received: by 10.152.135.105 with SMTP id pr9mr4690843lab.19.1325079377835; Wed, 28 Dec 2011 05:36:17 -0800 (PST) Received: from dfleuriot-at-hi-media.com ([83.167.62.196]) by mx.google.com with ESMTPS id s13sm24815716lad.8.2011.12.28.05.36.16 (version=SSLv3 cipher=OTHER); Wed, 28 Dec 2011 05:36:17 -0800 (PST) Message-ID: <4EFB1B4F.2090504@my.gd> Date: Wed, 28 Dec 2011 14:36:15 +0100 From: Damien Fleuriot User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.6; rv:8.0) Gecko/20111105 Thunderbird/8.0 MIME-Version: 1.0 To: freebsd-questions@freebsd.org References: <20111228075422.GA18064@admin.sibptus.tomsk.ru> <4EFAE80D.9040900@my.gd> <20111228130734.GA23763@admin.sibptus.tomsk.ru> In-Reply-To: <20111228130734.GA23763@admin.sibptus.tomsk.ru> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: Re: mutual forwarders in ISC BIND X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 28 Dec 2011 13:36:19 -0000 On 12/28/11 2:07 PM, Victor Sudakov wrote: > Damien Fleuriot wrote: >> >> If you're trying to build up a cache to improve performance and response >> time, here's your scenario: >> >> DNS C, forward to DNS A,B for all queries >> DNS D, forward to DNS B,A for all queries >> >> Your cache will start building up and only responses that are not cached >> will be taken from your NS A and B servers. > > Sorry, I fail to see how this is any better than two independent DNS > servers. Perhaps a variant like > > DNS C, forward to DNS A > DNS D, forward to DNS A > > would be close to the goal of cache consolidation. > DNS A suffers an outage ; you're fucked, to put it bluntly. > Matthew Seaman wrote: >> >> If you want to consolidate caches then probably your best bet is to have >> fewer, but larger resolvers. A pretty standard server class machine >> dedicated to recursive DNS should be easily capable of supporting many >> thousands of clients. > > You are certainly right. > >> >> DNS is not really a fruitful target for reducing traffic volume -- there >> really isn't that much of it compared to all other types in any case. >> It's also pretty critical to the perceived performance of your networks. >> Complicating and slowing down the DNS lookup path just makes everything >> look slow. > > I just wanted the servers to benefit from each other's caches. That > could speed up the lookups. > > On a side note, have you considered unbound ? It may be better suited to your needs and scale.