*BSD News Article 52744


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Path: euryale.cc.adfa.oz.au!newshost.anu.edu.au!harbinger.cc.monash.edu.au!simtel!chi-news.cic.net!uwm.edu!spool.mu.edu!agate!soda.CSUA.Berkeley.EDU!forest
From: forest@soda.CSUA.Berkeley.EDU (Forest Edward Wilkinson)
Newsgroups: comp.mail.sendmail,comp.unix.bsd.freebsd.misc
Subject: Re: Please Help:  Name server timeouts from sendmail
Date: 9 Oct 1995 23:22:39 GMT
Organization: Univ. of Calif. Berkeley Computer Science Undergrad Assoc.
Lines: 36
Message-ID: <45carv$a2h@agate.berkeley.edu>
References: <451uoc$4o5@agate.berkeley.edu> <456tb1$61k@uriah.heep.sax.de>
NNTP-Posting-Host: soda.csua.berkeley.edu
Summary: but why the timeout?
Keywords: sendmail bind named dns freebsd firewall timeout queue smart host
Xref: euryale.cc.adfa.oz.au comp.mail.sendmail:21046 comp.unix.bsd.freebsd.misc:7249

In article <456tb1$61k@uriah.heep.sax.de>,
J Wunsch <j@uriah.heep.sax.de> wrote:

>Well, kill you firewall. :-)

I wish.

>FEATURE(nocanonify) is probably what you are looking for.  Perhaps you
>need both (nocanonify and nodns), that's what i'm using here.

What exactly does "nocanonify" do?

>"nodns" is misleading: of course, as long as your libc is still using the
>resolver, sendmail _will_ use the DNS.  It only avoids speaking to DNS
>_directly_, bypassing the resolver library.

Oh!  Yes, sendmail does appear to be using DNS properly (through the
resolver) when "nodns" is specified.  Thank you!

Now I'm curious... why would sendmail time out when talking to DNS
directly, when the resolver functions just fine.  I would expect a
lookup failure on hosts outside our network, not a timeout.  After all,
that's what I get from nslookup.

Also, if the libc resolver is used anyway, why does sendmail talk
directly to DNS by default?  Does it need to do so in order to find MX
records?  If that's the case, am I losing MX functionality by specifying
"nodns"?


Thanks again,

Forest

-- 
森      forest@csua.berkeley.edu