CNAME records having MX

[Joseph S D Yao]

On Sat, Dec 15, 2001 at 12:31:38AM +0100, Michael Kjorling wrote:
> 
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
> 
> Actually you are thinking the wrong way around here... or at least
> that's how I interpreted the question. Let's take a look at what you
> did NOT quote:
> 
> > > A CNAME can point to an MX, that is fine.
> >
> > nope.
> 
> I'd interpret this as something on the order of:
> 
> 	foo.com. MX 10 bar.foo.com.
> 	bar.foo.com. A 123.45.67.89
> 	baz.foo.com. CNAME bar.foo.com.
> 
> Which is perfectly legal, unless someone changed that recently. If
> they did, I am in major trouble as I am doing exactly that myself in a
> couple dozen zones, and I bet there are people doing this for bigger
> setups as well.
> 
> I agree that it is not allowed to point a MX RR *at* a CNAME RR,
> though; like this:
> 
> 	foo.com. MX 10 bar.foo.com.
> 	bar.foo.com. CNAME baz.foo.com.
> 	baz.foo.com. A 123.45.67.89
> 
> But that was never the question in this case.

It is not clear what "A CNAME can point to an MX" means, I will agree.
It is also not clear - and this was the original question - what
"a CNAME record can't have an MX record associated with it" means.  I
take both to mean that the LHS of an MX record is an alias - that is,
is also the LHS of a CNAME record.

	bar.foo.com.	CNAME	baz.foo.com.
	bar.foo.com.	MX  10	booboo.foo.com.

This last, which you do not mention above, is also clearly wrong.

My original answer is at
<URL: http://marc.theaimsgroup.com/?l=bind-users&m=100800992615882&w=2>
and I should have let it go at that.

-- 
Joe Yao				jsdy at center.osis.gov - Joseph S. D. Yao
OSIS Center Systems Support					EMT-B
-----------------------------------------------------------------------
   This message is not an official statement of OSIS Center policies.