From owner-freebsd-questions Fri May 4 7:32:55 2001 Delivered-To: freebsd-questions@freebsd.org Received: from d9168.upc-d.chello.nl (d9168.upc-d.chello.nl [213.46.9.168]) by hub.freebsd.org (Postfix) with ESMTP id 526B337B43F for ; Fri, 4 May 2001 07:32:53 -0700 (PDT) (envelope-from edwin@d9168.upc-d.chello.nl) Received: by d9168.upc-d.chello.nl (Postfix, from userid 1001) id 4C01434C; Fri, 4 May 2001 16:32:52 +0200 (CEST) Date: Fri, 4 May 2001 16:32:52 +0200 From: Edwin Groothuis To: Wayne Pascoe Cc: freebsd-questions@freebsd.org Subject: Re: Purpose of serial number in zone files (BIND) Message-ID: <20010504163252.D50786@d9168.upc-d.chello.nl> Mail-Followup-To: Edwin Groothuis , Wayne Pascoe , freebsd-questions@freebsd.org References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: ; from wayne.pascoe@realtime.co.uk on Fri, May 04, 2001 at 03:14:18PM +0100 Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Fri, May 04, 2001 at 03:14:18PM +0100, Wayne Pascoe wrote: > Bind question. What is the purpose of the serial number in the zone > files? Is it only so that secondary name servers know that a change > has happened? Does it have any use for the local named process? Do > servers querying an authoritative server use this at all? In the DNS setup, you have one master server and one or more slave servers. The slave servers try to keep as up to date as possible with the data on the master server. They do this by requesting the SOA record of a zone, which hold data like the Time To Live of the data, the expire time and the serial number. If the serial of a zone on the slave is smaller than the serial number of a zone on the master, it means the data on the master has been changed and that the slaves have to download the whole zone again. Edwin -- Edwin Groothuis | Personal website: http://www.MavEtJu.org edwin@mavetju.org | Interested in MUDs? Visit Fatal Dimensions: ------------------+ http://FatalDimensions.nl.eu.org/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message