From owner-freebsd-questions Mon May 8 8:38:46 2000 Delivered-To: freebsd-questions@freebsd.org Received: from larryboy.graphics.cornell.edu (larryboy.graphics.cornell.edu [128.84.247.48]) by hub.freebsd.org (Postfix) with ESMTP id 6A3BA37B92E for ; Mon, 8 May 2000 08:38:42 -0700 (PDT) (envelope-from mkc@larryboy.graphics.cornell.edu) Received: from larryboy.graphics.cornell.edu (mkc@localhost) by larryboy.graphics.cornell.edu (8.9.3/8.9.3) with ESMTP id LAA68497; Mon, 8 May 2000 11:37:04 -0400 (EDT) (envelope-from mkc@larryboy.graphics.cornell.edu) Message-Id: <200005081537.LAA68497@larryboy.graphics.cornell.edu> To: "Marius Vincent" Cc: "freeBSD-Questions" Subject: Re: DNS In-Reply-To: Message from "Marius Vincent" of "Mon, 08 May 2000 16:49:05 +0200." Date: Mon, 08 May 2000 11:37:04 -0400 From: Mitch Collinsworth Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG >Can anyone tell me how a primary and a secondary dns server for the same >domain, exchange entries, or don't hey? The secondary config includes the location of the primary server. The secondary then requests a copy of the zone file from the primary. Every so often (as configured with refresh parameter in the SOA record) the secondary will request the SOA record from the primary and check to see if the serial number has changed. If primary's serial number is greater than secondary's serial number, secondary requests a new zone file transfer from primary. In addition to this, modern DNS servers will send a notify command from the primary to authoritative secondaries when a change is made on the primary. This allows secondaries to request updated info immediately rather that waiting until next refresh period. >For example, if I have a primary dns with the entry foo.bar.com pointing to >111.111.111.111 >and say a secondary DNS server for that domain without that record. >If i power off the primary DNS server all queries for that domain should go >to the secondary,but if foo.bar.com is not in the secondary - it will not >point there?? right?? or is there somehting i am missing? If secondary is configured with primary's IP address in the boot file, secondary will have the zone info and be able to resolve queries. >Or do you have to update the primary along with the secondary everytime you >want a record added for redundancy? If both systems have a modern DNS server, this will happen automatically via the notify mechanism. >Thanx > >Marius Vincent >Technical >ELCB Information Services If running DNS is part of your job, you should REALLY REALLY REALLY get, read, and fully comprehend the contents of "DNS and BIND" 3rd edition by Albitz and Liu, published by O'Reilly. There are lots and lots of ways you can shoot yourself in the foot if you try to be a DNS guy without reading this book. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message