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From: vixie@wrl.dec.com (Paul Vixie)
Newsgroups: comp.mail.sendmail
Subject: Re: sendmail.cf hostname named ?s
Keywords: sendmail setup config hostname named
Message-ID: <1990Oct13.083802.12321@wrl.dec.com>
Date: 13 Oct 90 08:38:02 GMT
References: <felps.655560162@convex.convex.com>
Sender: news@wrl.dec.com (News)
Distribution: comp
Organization: DEC Western Research Lab
Lines: 70

In article <felps.655560162@convex.convex.com>,
felps@convex.com (Robert Felps) writes:
# Environment:
#              Internet and UUCP(dial-up)
#              Domain   = abci.com
#              Hostname = asys
#              Primary named server
# 
# Questions:
#           1. What should the hostname command return?
#                  a. asys
#                  b. asys.abci.com

I have found that if a system is using a name server, it is generally
best to use fqdm's (fully qualified domain names, e.g., asys.abci.com)
in the "hostname" command.  Many people feel otherwise, and many of
those are militant about it, as am I.

#           3. What should Dj be set to?

I always use

	Dj$w

assuming that $w is set by sendmail to the value that gethostname(3n)
returned.  Ultrix Sendmail, in particular, strips the hostname after
the first "." when setting $w, a widely loathed practice (ULTRIX USERS --
IF ALL N,000 OF YOU SUBMIT AN SPR ON THIS, I CAN GET IT FIXED...)  Hwvr,
if you are using a reasonable sendmail, $w is safe and $j should be set
to it.

#           2. What should Cw (hostname) be set to?

	Cw$d $j localhost

Generally you want Cw to include both the qualified and the unqualified
names, which is the only argument for letting $w be unqualified and it's
not a very good one.  A proper config file is one that can safely be used
on any machine in a (sub-)domain, without per-host modifications.  Thus,
you define the (sub-)domain in some variable, say D, and when checking in
S0 for "this host" you say...

	R$+<@$->$*		$1<@$2.$D>$3		add our domain
	R$+<@$=w>$*		$1			strip local names

However, this will only work in IDA since multi-token class matches are
bogus in virtually all other sendmails.  So you'll probablay have to say:

	Cwlocalhost
	[...]
	R$+<@$->$*		$1<@$2.$D>$3		add our domain
	R$+<@$=w>$*		$1			strip local names
	R$+<@$d>$*		$1			strip local names
	R$+<@$j>$*		$1			strip local names

...unless you use Dj$w, in which case the last line is redundant.

# Any other tips would be helpful. I have sendmail.cf setup and seems
# to be working but would like to know the correct way some of these
# things should be done.

If you've got one that works, you're doing it right.  No smiley, that's
the nature of this ugly beast.  From here on in, every change you make
is a matter of your own personal taste and judgement.

Cheers,
--
Paul Vixie
DEC Western Research Lab	<vixie@wrl.dec.com>
Palo Alto, California		...!decwrl!vixie