[SATLUG] DNS Record Config

[Brad Knowles]

At 12:19 AM -0500 4/18/07, Bruce Dubbs wrote:

>  Now I want to create an MX record for domain2.org.  Should I just point
>  it to hostA.domain2.org?

That should work, yes.

>                            I think it should work, but the only issue is
>  that the reverse DNS will point to host2.domain1.org.  Will this be a
>  problem for mail?

Some bizarre whacked out sites may not like that.  But for most 
sites, it's okay that hostA.domain2.org and host2.domain1.org both 
point to the same IP address, and that the reverse DNS for that IP 
address only points to one of those names.  So long as the 
reverse/forward/reverse triplet works for the IP address, that should 
be fine.

That said, this will mean that some remote sites will tag your 
messages as coming from host2.domain1.org instead of 
hostA.domain2.org, in the "Received:" headers.  If you're okay with 
that, you shouldn't have too many problems.

Otherwise, you will want to run on completely separate IP addresses 
for the different domains.

>  I will want outgoing mail to be from user at domain2.org by default,
>  but a Mailman mailing list to have a Reply-to: listname at domain2.org.
>  This does not seem to be a DNS issue, but a MTA/Mailman issue that I can
>  handle separately.

Correct, that should be a separate issue.

Make sure you use real IP addresses and not CNAME aliases, however. 
See Mailman FAQ entry 6.22 at 
<http://www.python.org/cgi-bin/faqw-mm.py?req=show&file=faq06.022.htp> 
for more info.

>  Does this sound like a reasonable setup or are there issues that I don't
>  see?

So far as you've explained, this sounds like it should work fine. 
I'm already doing this in pretty much the same way on some of the 
domains that I help manage.

-- 
Brad Knowles <brad at shub-internet.org>, Consultant & Author
LinkedIn Profile: <http://tinyurl.com/y8kpxu>
Slides from Invited Talks: <http://tinyurl.com/tj6q4>