[CentOS] DNS wizard

Fri Dec 30 03:31:29 UTC 2005
Les Mikesell <lesmikesell at gmail.com>

On Thu, 2005-12-29 at 21:18, Sam Drinkard wrote:
> >
> >  
> >
> >>>@       A       216.104.158.222
> >>>vortex  A       216.104.158.222
> >>>@       MX      10 wa4phy.net.  ;Primary Mail Exchanger
> >>>         MX      20 smtp7.bagger.usbn.net. ;Secondary MX
> >>>www     CNAME   wa4phy.net.
> >>>ftp     CNAME   wa4phy.net.
> >>>      
> >>>
> >
> >  
> >
> >>Thanks Maze.. pretty much what I finally wound up with.  Guess things
> >>tend to change over time and I don't try to keep up with everything
> >>when it all still works.  
> >>    
> >>
> >
> >One other thing that might not be obvious: CNAMEs aren't
> >just for the A record, they get all associated data too
> >so you are providing an MX record for www.wa4phy.net
> >and ftp.wa4phy.net.  It doesn't hurt anything but it
> >might not be what you expect.
> >
> >  
> >
> Not sure I follow what you are talking about Les.  Can you be a bit more 
> specific?

Cnames are effectively the same as the record they
point to.  You probably intend for any mail sent to
user at wa4phy.net to be sent to the primary/secondary
MX receivers you specified, but as a side effect
of the CNAME, mail sent to user at www.wa4phy.net or
user at ftp.wa4phy.net would go to the same places because
the MX records also apply to them.  It isn't likely to
matter in this case, but someday you might want to 
direct mail to those addresses elsewhere and be surprised
that you can't give them a different MX.  Or if you
actually want mail to go to those addresses you might
be surprised when they sometimes hit the secondary
MX that might not be configured for them.

-- 
  Les Mikesell
   lesmikesell at gmail.com