From owner-freebsd-questions Sun Mar 12 12:14: 1 2000 Delivered-To: freebsd-questions@freebsd.org Received: from fremont.bolingbroke.com (adsl-216-102-90-210.dsl.snfc21.pacbell.net [216.102.90.210]) by hub.freebsd.org (Postfix) with ESMTP id 1382337BAE2 for ; Sun, 12 Mar 2000 12:13:58 -0800 (PST) (envelope-from hacker@bolingbroke.com) Received: from fremont.bolingbroke.com (fremont.bolingbroke.com [216.102.90.210]) by fremont.bolingbroke.com (Pro-8.9.3/Pro-8.9.3) with ESMTP id MAA82437; Sun, 12 Mar 2000 12:13:56 -0800 (PST) Date: Sun, 12 Mar 2000 12:13:55 -0800 (PST) From: Ken Bolingbroke To: FreeBSD Questions List Cc: Matthew Joseff Subject: Re: CNAME vs A records (clarification) In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Sun, 12 Mar 2000, Matthew Joseff wrote: > Can someone correct and/or confirm my understanding of CNAME vs A records: > > CNAME should be used for a host that exists on (potentially) another > server but uses that domain. > > A records should be used as an alias for a host but co-exists with other > hosts. > > So: > > www IN A (IP address) > foo IN A (same IP as www) > bar IN CNAME (some other IP or hostname) > etc IN A (bar's hostname) No, A records are the host addresses, and can only point to an IP address. CNAME records are aliases for A records. A more correct example would be: foo IN A 192.168.0.1 www IN CNAME foo bar IN A 10.0.0.1 etc IN CNAME bar And then in your reverse lookup zones, you'd have a PTR record for 192.168.0.1 -> foo and 10.0.0.1 -> bar. Normally, you should only have a single A record for any specific IP address and a correponding PTR record that reverses the A's IP and hostname. CNAMEs are aliases for 'extra' hostnames on the same IP address. > I think I'm confusing myself. O'Reilly's 'DNS and BIND' is an excellent reference. Ken Bolingbroke hacker@bolingbroke.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message