On Thu, 1 Mar 2001, Dave Sherohman wrote:
> > RFC says (somewhere, don't remember which one) forward and reverse have
> > to match, so having the following would be invalid:
>
> Learn something new every day.  But...
>
> IIRC, NS and MX records aren't supposed to point to CNAMEs, only to As.
> So wouldn't using only one A per IP make things a lot messier if you
> switch from hosting mail and DNS on the same machine to separate boxes
> or vice-versa?

That is true. That's what I use ip aliases for DNS and MX servers.  :)

> Also, the DNS-HOWTO (my admittedly near-sole source of information on
> the topic) includes a note that "A number of the arch-bind-wizards,
> recommend not using CNAME at all. But the discussion of why or why not
> is beyond this HOWTO."  Do these arch-bind-wizards choose to ignore the
> RFC you're referring to or have they come up with some way of reconciling
> the two approaches?

When I saw that comment, I stopped using CNAME's for a long time.. but I
was convinced otherwise and had the RFC thrown in my face later on. Not
sure why they said that..

> > This also makes it a helluva lot easier if we ever switch the IP of our
> > web server.
>
> If you want to look at it that way, sure...  It's the flip side of my earlier
> comment about CNAMEs outside the zone being more fragile.  The extra level of
> indirection makes moving the web server easier, but it also makes the
> referring zone vulnerable to loss of access to the zone containing the A
> record.

True.

-- 
Nate Carlson <natecars at real-time.com>   | Phone : (952)943-8700
http://www.real-time.com                | Fax   : (952)943-8500