From owner-freebsd-questions Fri Jun 2 21:54:50 2000 Delivered-To: freebsd-questions@freebsd.org Received: from fedde.littleton.co.us (fedde.littleton.co.us [216.17.174.44]) by hub.freebsd.org (Postfix) with ESMTP id 4588F37BA7D for ; Fri, 2 Jun 2000 21:54:47 -0700 (PDT) (envelope-from cfedde@fedde.littleton.co.us) Received: from fedde.littleton.co.us (localhost [127.0.0.1]) by fedde.littleton.co.us (8.10.0/8.10.0) with ESMTP id e534sX101369; Fri, 2 Jun 2000 22:54:33 -0600 (MDT) Message-Id: <200006030454.e534sX101369@fedde.littleton.co.us> To: Doug Barton Cc: webmaster@wmptl.com, questions@FreeBSD.ORG Subject: Re: IP vs CNAME In-Reply-To: <3938892F.FC65E69A@gorean.org> From: Chris Fedde Date: Fri, 02 Jun 2000 22:54:33 -0600 Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Fri, 02 Jun 2000 21:27:27 -0700 Doug Barton wrote: +------------------ | Nathan Vidican wrote: | > | > We are a relatively small ISP looking to grow. We're now starting to do | > virtualhosting for people, and thus far I've been setting up | > virtualhosts using cnames. | | Why are you using CNAME's? You are needlessly doubling the traffic to | your nameservers for every lookup. It's much better to define each host | as an A record that points to the IP address of your vhost'ing server. +------------------ This is obviously incorrect. A DNS response has plenty of room in it for multiple records. The response to a cname query contains the CNAME, potentially many A records and several authority records. The local name server is expected to cache these records to allow it to short circuit future requests for related data. My current thinking on this issue is that it is better to use a CNAME record for name based virtual hosts since it preserves the validity of name matching between A and PTR records. chris -- Chris Fedde 303 773 9134 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message