From: ellis@nova.gmi.edu (Stew Ellis)
Newsgroups: comp.protocols.tcp-ip.domains
Subject: MX records, top-level domains, and DNS propagation delays
Keywords: MX, DNS, propagation delays
Date: 7 Sep 92 19:45:40 GMT
Organization: GMI Engineering&Management Institute, Flint, MI

I am not certain this is the most appropriate group, so redirect me if it is
not.

I am a little confused by the relationship between domain name registration,
MX records, the output of whois and the output of nslookup.

The network administrator at our site wants to be more of an administrator
than a computerist.  While it is not my formal responsibility at our site, I
was the only one with any real sendmail configuration experience when we
went online with the Internet about 7 months ago, and I was the one who got
basic email configured.  I was also the only person around who had any real
UNIX networking experience, though not with TCP/IP, so I got the DNS and NIS
stuff working together ( that had something to do with reading the Sun
Network admin manual thoroughly and understanding enough UNIX to understand
the rest of it).  Since then I have read a couple of other vendors' DNS
docs, plus the new O'Reilly book on TCP/IP.

First, since the site is registered as gmi.edu, which happens to gateway to
the outside world through nova, why doesn't the the address user@gmi.edu
work by default, instead of nova.gmi.edu?  Is there anything that can be
done at our site so that email AND telnet AND ftp AND rlogin, etc. would
default to our main server (nova) when someone from the outside simply says
gmi.edu?  I gather we could reregister nova.gmi.edu as gmi.edu, but could we
do something similar with local cname records or something?

For email, I get the impression MX records should work.  I put an MX record
of the form:
*.gmi.edu.	in	mx	0	nova.gmi.edu.
in our named.hosts (that is not what it is called locally) file after all of
the a records and aliases (just stuff like mailhost, etc).
It sat there for over a month without seeming to take effect.  I was
unsophisticated about the uses of nslookup, so I am not sure whether it ever
propagated or not before I removed it.

Today, I put a line of the form:
	in	MX	0	nova.gmi.edu
right after the NS records at the top of the named.hosts file.

Using the 'set type=any' command in nslookup, then typing 'gmi.edu' while
using nova.gmi.edu as the server, it shows an mx record to be in effect.  I
can mail from myself locally, to myself as ellis@gmi.edu, which used to not
work, but now does.  If I set the server to other nearby ones however, they
do not show the mx record in effect.  Am I leaving out some important step,
or does it take some multiple of forever to propagate?  To get the changes
to take effect locally, I did a 'kill -1 <pid of in.named>.  

Any help would be appreciated.

--
--                                                        ___________________
  R.Stewart(Stew) Ellis, Assoc.Prof., (Off)313-762-9765  /   _____  ______ 
  Humanities & Social Science,  GMI Eng.& Mgmt. Inst.   /        / /  /  / /
  Flint, MI 48504      ellis@nova.gmi.edu              /________/ /  /  / /
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