Path: utzoo!attcan!uunet!husc6!bloom-beacon!mit-eddie!bbn!rochester!pt.cs.cmu.edu!andrew.cmu.edu!cfe+
From: cfe+@andrew.cmu.edu (Craig F. Everhart)
Newsgroups: comp.mail.sendmail
Subject: Re: Sendmail/resolver problem
Message-ID: <8XJXoXy00VsLE0VVkX@andrew.cmu.edu>
Date: 14 Oct 88 17:45:07 GMT
References: <22426@tis.llnl.gov>
Organization: Carnegie Mellon
Lines: 20
In-Reply-To: <22426@tis.llnl.gov>

Ideally, you would get to specify (from your sendmail.cf) whether the
underlying getcanonname() routine should attempt appending default domain names
or not.  Actually, you can specify whether to try default domain names: if you
append a ``.'' to the domain name, the resolver isn't supposed to try to append
default names.

I believe that the list of ``default domains'' attempted does not include the
parent's top-level domain, precisely so that one doesn't bang on the root
servers looking for ``gov.gov'' or whatever.  That is, using your example, if
your host name is a.foo.bar.gov and you're looking up b.foo.bar.gov, your
resolver will try
        b.foo.bar.gov.foo.bar.gov
        b.foo.bar.gov.bar.gov
        b.foo.bar.gov
That is, it isn't supposed to be trying
        b.foo.bar.gov.gov
And if you ask about ``b.foo.bar.gov.'', it shouldn't be appending any suffixes.

                Craig Everhart
                Andrew message system