Mailing List SIMS@mail.stalker.com Message #5645
From: <billc@greenbuilder.com>
Subject: Re: MX pointing to CNames? (was: Backup mailer)
Date: Sun, 26 Mar 2000 09:19:19 -0600
To: SIMS Discussions <SIMS@mail.stalker.com>
>At 4:30 PM -0500 3/25/00, billc@greenbuilder.com wrote:
>
>
>> >At 11:38 AM -0500 3/25/00, billc@greenbuilder.com wrote:
>>
>> >> My MX records are presently
>> >>
>> >> mydomain.com MX 10 mail.mydomain.com
>> >> mail.mydomain.com A xxx.xxx.xxx.1
>> >>
>> >> domain1.com MX 10 mail.domain1.com
>> >> mail.domain1.com C mail.mydomain.com
>>
>> Bill Cole wrote:
>>
>> >Are those 'C's indicating CNAME records?
>> >
>> >That's bad. Never point an MX at a CNAME. Half the net won't understand,
>> >and the rest shouldn't. It's *WRONG*
>> >
>> >If you really fee the need to have the mail.domainx.com names exist, make
>> >them A records. There is no harm in having multiple names' A records share
>> >an address.
>> >
>>
>> > Lose the CNAME records. They are useless.
>> >
>> >If you MUST have them for some other reason, still make sure you don't
>> >have MX records pointing at the CNAME names. That is bad. It is counter to
>> >the DNS spec. It is unnecessary. Don't do it. It breaks things.
>> >
>> >
>>
>> I've never heard that before.  It seems to be working just fine.  I'm
>> checking with the folks over on the QDNS list just to make sure, but if I
>> remember correctly I got it from a fairly reliable source that it's an OK
>> thing to do.
>>
>> I set it up that way because the IP address of mail.mydomain.com may change
>> - it's been known to happen in the past.  It's sure a heck of a lot easier
>> to have ONE place to change the IP address than having to change all of my
>> DNS records.  So for me, it's not completely useless.
>
>Then just point the MX records to mail.mydomain.com. You don't gain
>anything by pointing them at mail.domainx.com. Really.
>
>RFC's in support of this are 974, 1034, 1713, and 1912. Of course, the
>people on the QDNS mailing list might disagree, but you are free to chose
>your preferred authorities.
>

Nope, they agreed.  I stand corrected - and so do my MX records.  Thanks
for setting me straight.

BC

Bill Christensen
billc@greenbuilder.com

Green Homes For Sale/Lease:  http://www.greenbuilder.com/realestate/
Green Building Pro Directory:  http://www.greenbuilder.com/directory/
Sustainable Bldg Calendar:  http://www.greenbuilder.com/calendar/
Sustainable Bldg Bookstore: http://www.greenbuilder.com/bookstore


Subscribe (FEED) Subscribe (DIGEST) Subscribe (INDEX) Unsubscribe Mail to Listmaster