Newsgroups: comp.mail.sendmail
Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!caen!news.cs.indiana.edu!ux1.cso.uiuc.edu!mp.cs.niu.edu!rickert
From: rickert@mp.cs.niu.edu (Neil Rickert)
Subject: Re: Sendmail host canonicalization broken?
Message-ID: <1991Apr12.235346.28444@mp.cs.niu.edu>
Organization: Northern Illinois University
References: <3006@weber.sw.mcc.com>
Date: Fri, 12 Apr 1991 23:53:46 GMT
Lines: 39

In article <3006@weber.sw.mcc.com> knutson@weber.sw.mcc.com (Jim Knutson) writes:
>I've been trying to trace down a problem I've been having with name
>canonicalization using $[ $].  I want to be able to resolve host.sub
>into host.sub.top.domain or host into host.top.domain.

>For example, my domain is sw.mcc.com.  I want to be to send:

>user@bc.cad -> user@bc.cad.mcc.com

>The reason this is happening is because maphostname() turns off
>recursive domain name matching (RES_DNSRCH) before calling
>getcanonname().  The reason given for this is as follows:

>Now, what I really want to know is whether or not this is a valid
>argument.  I think that resolving uucp names into internet names using

 1.  You should have identified this as an IDA version of sendmail.  In the
     standard Berkeley versions RES_DNSRCH is not turned off.

 2.  Here is a good reason for turning off RES_DNSRCH:

	Suppose someone in your French department has a machine called
	eiffel.fr.mcc.com.  (OK.  You aren't a University, and you don't
	have a French Department.  But let's pretend here for a moment.)
	Now imagine you wish to send a message to 'user@eiffel.fr' -- the
	real eiffel.fr, that is, in France.  You can't if RES_DNSRCH is
	turned on, because it will always go to your French department.

 3.  You do have a good alternative.  With the IDA package, just define
     DOMAINTABLE, and you can translate anything into anything.  This
     differs from RES_DNSRCH in that you have deliberately chosen which
     name to translate, rather than it depending on the accident of what
     new machines have been defined in a parent domain.

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