From owner-freebsd-questions@FreeBSD.ORG Fri Oct 23 14:22:50 2009 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 8876210656A7 for ; Fri, 23 Oct 2009 14:22:50 +0000 (UTC) (envelope-from millenia2000@hotmail.com) Received: from bay0-omc1-s29.bay0.hotmail.com (bay0-omc1-s29.bay0.hotmail.com [65.54.246.101]) by mx1.freebsd.org (Postfix) with ESMTP id 705B08FC0C for ; Fri, 23 Oct 2009 14:22:50 +0000 (UTC) Received: from BAY126-W8 ([65.55.131.43]) by bay0-omc1-s29.bay0.hotmail.com with Microsoft SMTPSVC(6.0.3790.3959); Fri, 23 Oct 2009 07:22:49 -0700 Message-ID: X-Originating-IP: [65.214.169.254] From: Sean Cavanaugh To: "freebsd-questions@freebsd.org" Date: Fri, 23 Oct 2009 10:22:50 -0400 Importance: Normal In-Reply-To: <4AE1A1D0.8060402@pixelhammer.com> References: <4AE1A1D0.8060402@pixelhammer.com> MIME-Version: 1.0 X-OriginalArrivalTime: 23 Oct 2009 14:22:49.0692 (UTC) FILETIME=[4CA799C0:01CA53EC] Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable X-Content-Filtered-By: Mailman/MimeDel 2.1.5 Subject: FW: DNS Question 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: Fri, 23 Oct 2009 14:22:50 -0000 > Date: Fri=2C 23 Oct 2009 08:30:08 -0400 > From: dave.list@pixelhammer.com > To: freebsd-questions@freebsd.org > Subject: DNS Question >=20 > Good morning. >=20 > I have been asked by my co-workers and sales why I always create a A=20 > record for new domains we host instead of a CNAME. >=20 > The issue I run into lately with some domains is that a client has a=20 > website with a industry host such as frank.relator.com and he wants to=20 > have DNS point www.frank.com to frank.relator.com with a CNAME. The=20 > client does not want an A record for frank.com. >=20 > Somewhere=2C in a class far far away=2C I was taught a DNS zone had to ha= ve=20 > a A record to function properly. I can't seem to locate anything in the=20 > RFCs. >=20 > Am I wrong? >=20 =20 I think you are confusing basics of DNS records. you are partially correct = in that a DNS zone needs an initial A record to be able to translate a name= to an IP=2C but there is nothing wrong about setting up a CNAME to point t= o a record in a different zone instead. you just cannot do a zone that has = a CNAME only that does not at some point to a valid A record. CNAMEs are fo= rwarders only whereas A records are actual lookups. =20 for proper way to set this up.... =20 The A record would be assigned for the main name that you want to associate= to an IP address. The CNAME record just relates a different name to that original name. this = allows you to change the IP address of the server and only have to update t= he original A record instead of every DNS record for that server. =20 for small number of vhosts=2C this would not really be an issue=2C but imag= ine if you were hosting a couple hundred vhosts from a single IP and then h= ad to change that IP because you switched your ISP. It would take you a LON= G time to update them if they were all A records=2C but only a couple of se= conds if you had it properly set up as CNAME's =20 www.bobshosting.com A 192.168.0.1 www.vhost1.com CNAME www.bobshosting.com. www.vhost2.com CNAME www.bobshosting.com. www.vhost3.com CNAME www.bobshosting.com. www.vhost4.com CNAME www.bobshosting.com. =20 =20 -Sean =