From owner-freebsd-questions@FreeBSD.ORG Wed Nov 24 15:47:19 2004 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 6805316A4CE for ; Wed, 24 Nov 2004 15:47:19 +0000 (GMT) Received: from hobbiton.shire.net (hobbiton.shire.net [166.70.252.250]) by mx1.FreeBSD.org (Postfix) with ESMTP id 17F8F43D31 for ; Wed, 24 Nov 2004 15:47:19 +0000 (GMT) (envelope-from chad@shire.net) Received: from [67.161.247.57] (helo=[192.168.99.66]) by hobbiton.shire.net with esmtpsa (TLSv1:RC4-SHA:128) (Exim 4.43) id 1CWzMU-000F2C-L0 for freebsd-questions@freebsd.org; Wed, 24 Nov 2004 08:47:18 -0700 Mime-Version: 1.0 (Apple Message framework v619) In-Reply-To: <41A4A8CD.3020904@circlesquared.com> References: <20041123233501.GA82229@dogma.freebsd-uk.eu.org> <5557305861.20041124004849@hexren.net> <20041124000014.GA83249@dogma.freebsd-uk.eu.org> <8763344284.20041124022927@hexren.net> <20041124141737.GA11648@dogma.freebsd-uk.eu.org> <5315017844.20041124160806@hexren.net> <20041124152355.GD11648@dogma.freebsd-uk.eu.org> <41A4A8CD.3020904@circlesquared.com> Message-Id: <1C062492-3E30-11D9-BC47-003065A70D30@shire.net> From: "Chad Leigh -- Shire.Net LLC" Date: Wed, 24 Nov 2004 08:47:13 -0700 To: FreeBSD questions list X-Mailer: Apple Mail (2.619) X-SA-Exim-Connect-IP: 67.161.247.57 X-SA-Exim-Mail-From: chad@shire.net Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Checker-Version: SpamAssassin 3.0.0 (2004-09-13) on hobbiton.shire.net X-Spam-Status: No, score=-0.3 required=5.0 tests=AWL,BAYES_50 autolearn=disabled version=3.0.0 X-Spam-Level: X-SA-Exim-Version: 4.1+cvs (built Mon, 23 Aug 2004 08:44:05 -0700) X-SA-Exim-Scanned: Yes (on hobbiton.shire.net) Subject: Re: 4 part domain names X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 24 Nov 2004 15:47:19 -0000 the "zone" description listed was pretty good. Basically, the leftmost name in a fully qualified domain name is the "host" (which could really be an alias or something) and the rest is the domain name. So for example u17.us.mail.somecompany.com u17 is the "host" (in this fictional account, a departmental mail server in the US division of somecompany) us.mail.somecompany.com is the "domain" The names get more general from left to right. It is a hierarchy. Similar to a postal address. For example John Doe 17 Main Street Anytown, TX 75263 USA John Doe is the "host" 17 is a specific location on a general street "Main Street" which is found in Anytown which is found in TX which is found in the USA. As a domain name it might be written JohnDoe.17.MainStreet.75263.Anytown.TX.USA Alfons Mueller Schardthof 10 D-84051 Essenbach Germany would be the same. AlfonsMueller.10.Schardthof.84051.Essenbach.Bayern.Germany is a progressively more general description of where Mr. Alfons Mueller can be located. When you send a postal letter to one of these people (John Doe or Alfons Mueller), the letter is sent to the respective country's main postal "office", then to a regional and then a city and then maybe a neighborhood (depending on your area) post office before being delivered. The hierarchy helps the routing of the mail. Same with domain names. The hierarchy helps to keep trach of the complexity in a delegated fashion Sorry for the complex examples Chad