On Tue, 18 Jan 1994 15:26:18 EST Stan Horwitz said:
>...
>posting or so  from Help-Net gets bounced  by our mailer with  a host unknown
>message  for [log in to unmask]  I  won't  include a  sample
 
   Since this is a "classic" dns problem I'll reply to the list.  The domain
name system is amazing - some days it is amazing it works at all!  ;-)
But seriously, if you are getting variable results you need to check ALL
the servers for specific zone.  In this case it looks like the host name
is in the zone TEMPLE.EDU which appears to have two servers.  Queries for MX
and A records to BOTH of these give very different results.  The list below
is a local tool because it's the only I've found which will query all the
servers of the zone automatically but you can do it with dig or nslookup.
It looks like the charon.psc.edu server is out of date or messed up
with a bad CNAME (points to self).
 
   Not to pick on TEMPLE.EDU but there seem to be some other inconsistencies
between the two servers or in the SOA records.
 
   If you want to notify someone of the problem then you probably want to
go to SOA contacts (assuming the address is correct!) and whois entries.
 
        Marty
 
Example of different answers from different TEMPLE.EDU servers:
 
 
=== QNS compserv.ocis.temple.edu . === 18 Jan 1994 17:13:04                 ===
 
--- Query Name: COMPSERV.OCIS.TEMPLE.EDU  Qtype: MX                         ---
    Server 1/2:  COMVAX.OCIS.TEMPLE.EDU 129.32.1.2
Question:
  1 COMPSERV.OCIS.TEMPLE.EDU MX IN
Answer(s):                             (ie. Primary Results of the Query)
  1 COMPSERV.OCIS.TEMPLE.EDU MX IN 3600  0,compserv.ocis.temple.edu
Additional:                                    (ie. A records for others)
  1 compserv.ocis.temple.edu A IN 3600 155.247.27.86
                                                  Elapsed time  3.99 sec.
--- Query Name: COMPSERV.OCIS.TEMPLE.EDU  Qtype: A                          ---
    Server 1/2:  COMVAX.OCIS.TEMPLE.EDU 129.32.1.2
Question:
  1 COMPSERV.OCIS.TEMPLE.EDU A IN
Answer(s):                             (ie. Primary Results of the Query)
  1 COMPSERV.OCIS.TEMPLE.EDU A IN 3600 155.247.27.86
                                                  Elapsed time  3.15 sec.
--- Query Name: COMPSERV.OCIS.TEMPLE.EDU  Qtype: MX                         ---
    Server 2/2:  CHARON.PSC.EDU 128.182.65.6
Question:
  1 COMPSERV.OCIS.TEMPLE.EDU MX IN
Answer(s):                             (ie. Primary Results of the Query)
  1 COMPSERV.OCIS.TEMPLE.EDU CNAME IN 3600 compserv.ocis.temple.edu
  2 compserv.ocis.temple.edu CNAME IN 3600 compserv.ocis.temple.edu
                                                  Elapsed time  3.50 sec.
--- Query Name: COMPSERV.OCIS.TEMPLE.EDU  Qtype: A                          ---
    Server 2/2:  CHARON.PSC.EDU 128.182.65.6
Question:
  1 COMPSERV.OCIS.TEMPLE.EDU A IN
Answer(s):                             (ie. Primary Results of the Query)
  1 COMPSERV.OCIS.TEMPLE.EDU CNAME IN 3600 compserv.ocis.temple.edu
  2 compserv.ocis.temple.edu CNAME IN 3600 compserv.ocis.temple.edu
                                                  Elapsed time  3.27 sec.
    End of queries.     2.0 of 2 successful (100%)