Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!uwm.edu!linac!mp.cs.niu.edu!rickert
From: rickert@mp.cs.niu.edu (Neil Rickert)
Newsgroups: comp.protocols.tcp-ip
Subject: Re: Confirming DNS name matches local host name
Message-ID: <1991May30.210422.15605@mp.cs.niu.edu>
Date: 30 May 91 21:04:22 GMT
References: <891@bcstec.boeing.com>
Distribution: na
Organization: Northern Illinois University
Lines: 33

In article <891@bcstec.boeing.com> ced@bcstec.uucp (Charles Derykus) writes:
>Given an internet IP, is there a way to retrieve what the host at that IP
>actually calls itself. In other words, I want to confirm that what DNS
>says actually matches the local host name.
>
>I thought telneting in through the "smtp" port and capturing the output 
>would be an option but the "smtp" output resists capture.
>
 By "resists capture", I presume you mean you wish to run this from a script.
(Do you have 'mconnect', and if so, did you try this)?

 I am not sure what you expect by telnetting to the smtp port.  That isn't
going to tell you what the host calls itself.  It will tell you what the
smtp software on the host call itself.  Given how common misconfigured
mail software is, I would trust the DNS over the smtp dialogue for giving
the name.

 Then there is the question of what you mean by "what the host actually
calls itself".  A good guess is that when it is talking to itself, it
usually calls itself 'localhost', but somehow I doubt that this is what
you mean.

 Do you mean `hostname`?.  Do you mean `hostname`.`domainname` (assuming
that domainname exists)?  Do you mean the result of canonicalizing one of
these with a host table lookup?  or with a DNS lookup?  And in any case,
why would you care?


-- 
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  Neil W. Rickert, Computer Science               <rickert@cs.niu.edu>
  Northern Illinois Univ.
  DeKalb, IL 60115                                   +1-815-753-6940