DNS: to CNAME or not to CNAME?

why use CNAME records at all? if i have an A record that says
"mail.mydomain.com=192.168.1.1", why create a CNAME record that says
"mail2.mydomain.com=mail.mydomain.com" when i can just create another A
record that says "mail2.mydomain.com=192.168.1.1"?

<(E-Mail Removed)> wrote in message
news:SnBAc.3679$(E-Mail Removed) ...
> why use CNAME records at all? if i have an A record that says
> "mail.mydomain.com=192.168.1.1", why create a CNAME record that says
> "mail2.mydomain.com=mail.mydomain.com" when i can just create another A
> record that says "mail2.mydomain.com=192.168.1.1"?

Because next week, your ISP will tell you that your site is moving from
192.168.1.1 to 10.1.2.3, and you'll edit your mail.mydomain.com setting, but
forget to fix your mail2.mydomain.com setting.

You have to decide whether these two host names refer to _conceptually_ the
same host (in which case, one really is just another name for the other, and
you would use a CNAME), or coincidentally the same host (in which case, they
only share the same IP address for now, and moving one might not affect the
other).

Alun.
~~~~

On Fri, 18 Jun 2004 12:39:14 GMT, <(E-Mail Removed)> wrote:

>why use CNAME records at all? if i have an A record that says
>"mail.mydomain.com=192.168.1.1", why create a CNAME record that says
>"mail2.mydomain.com=mail.mydomain.com" when i can just create another A
>record that says "mail2.mydomain.com=192.168.1.1"?

Because when the IP changes due to a renumbering, change in provider,
etc. you change only the one record.

Jeff