[vox-tech] some people can't send to list

[Nick Schmalenberger]

On Tue, Mar 17, 2015 at 05:41:32PM -0700, Tony Cratz wrote:
> On 03/16/2015 11:56 PM, Wes Hardaker wrote:
> > This is fine:
> > 
> >   # dig lugod.org mx
> > 
> >   ;; ANSWER SECTION:
> >   lugod.org.              3600    IN      MX      10 www.lugod.org.
> > 
> > This is not:
> > 
> >   # dig www.lugod.org.
> > 
> >   ;; ANSWER SECTION:
> >   www.lugod.org.          3600    IN      CNAME   lugod.org.
> >   lugod.org.              3600    IN      A       173.13.165.50
> > 
> > *some* (most) DNS resolution software lets you get away with that, but
> > it's not legal according to the DNS RFCs and shouldn't be done.
> > 
> > 
> > The right thing to do would be to replace the MX record so it looked
> > like this:
> > 
> >   lugod.org.              3600    IN      MX      10 lugod.org.
> > 
> > Which would then work.  Though, the best thing to do is actually create
> > a new host record:
> > 
> >   lugod.org.              3600    IN      MX      10 mail.lugod.org.
> >   mail.lugod.org.         3600    IN      A       173.13.165.50
> > 
> 
> 	In all the years of be being a Sys. Admin., this issue has been
> 	very high on the problem list.
> 
> 	I have gotten to the point where I refuse to ever use a CNAME.
> 	I wish that CNAME was never invented.
> 
> 
> 								Tony
>
Yeah, but honestly why is it a problem anyway? Sure it allows
creating DNS loops and other weird stuff, but it can also be
useful (like a lot of things that can make loops).

It is possible with a sophisticated DNS service like Amazon
Route53 to resolve the equivalent sort of logic internally and
spit out an A record in response to the first request, and still
allow geo or other load balancing.

At my work we use Route53, and it lets us also chain CNAMEs if we
choose. The benefit of that I think is it makes it easier for the
client to see how the logic is working. I can see both sides
here, but why should this be a rule?
-Nick