Skip site navigation (1)Skip section navigation (2)
Date:      Fri, 16 Nov 2001 10:12:09 -0500
From:      Louis LeBlanc <leblanc+freebsd@keyslapper.org>
To:        freebsd-questions@FreeBSD.ORG, freebsd-questions@FreeBSD.ORG
Subject:   Re: sendmail doesn't like changed nameservers
Message-ID:  <20011116151209.GA57485@keyslapper.org>
In-Reply-To: <86lmh7htn0.fsf@unicorn.ea4els.ampr.org>
References:  <20011115184242.GA43009@keyslapper.org> <86lmh7htn0.fsf@unicorn.ea4els.ampr.org>

next in thread | previous in thread | raw e-mail | index | archive | help

--45Z9DzgjV8m4Oswq
Content-Type: text/plain; charset=unknown-8bit
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable

On 11/16/01 11:55 AM, Simon J Mudd sat at the `puter and typed:
> leblanc+freebsd@keyslapper.org (Louis LeBlanc) writes:
>
> > What I  can't figure  out is how  to get sendmail  to pick  up the
> > nameserver change on  the fly. I wound up having  to kill sendmail
> > from /etc/mail/  using make  stop. I  then had to  ps -ax  for the
> > remaining sendmail processes and kill them explicitly. Otherwise I
> > kept getting resolve errors in /var/log/maillog.
>
> Most MTAs, and  I don't think sendmail is an  exception, don't use a
> specific nameserver themselves. That depends on what have configured
> in /etc/resolv.conf.  I assume that you  are still using the  old ip
> setup before?

Yes, but  what if  you change  resolv.conf midstream on  it? I  had to
restart my  browser, because it couldn't  find anything. I also  got a
bunch of ipfw  denials out to the  old nameservers on port  53 until I
got all the daemons that use /etc/resolv.conf.

> In any case  it is often more convenient to  setup named locally and
> let it  do all the  work, rather than  rely on your  provider's name
> server changing ip addresses.

I've been  balking at this  because I'm not  very familiar with  it. I
guess I  should find a  quick and dirty guide  online and do  it. It'd
save a  lot of hassles.  I assume you're  not talking about  a caching
only nameserver?

> If you do  this you can set  up resolv.conf to have  3 name servers,
> the first one it would use would be your local named, and the others
> could be the ones setup by your dhcp client script.

Can't you use more than three?  My ISP gives me three.

> > Is it possible  to get sendmail to do this  more gracefully from a
> > script? What  is the general  consensus for calling  'killall -HUP
> > sendmail'? If that is BAD, let me know so I don't do it :).
>
> The problem  isn't sendmail, it's  the name resolution, and  the way
> this  works is  setup in  /etc/resolv.conf  (and a  couple of  other
> files).

Other files?

> I think you are blaming the wrong tool here.

I wouldn't  say I'm 'blaming' anyone  :) It just looked  like sendmail
read  /etc/resolv.conf at  startup, and  never bothered  to reread  it
before  any other  lookups. Hence  the continued  attempts to  the old
nameservers.

> > Anyway, I  don't think  I lost  any mail (maybe  a couple),  but I
> > would like  this to be  automated so I  don't really need  to know
> > when I get a change in my dhcp lease.
>
> I'd look  at the chcp  client script and see  how to setup  the name
> server to  use, or better  still setup  named properly so  you don't
> _need_ to use your providers own name server.

Yes, I  had one that  did that  before, and it  really was hosed  - it
tended to hose resolv.conf badly.

Thanks for the pointers.
Lou
--=20
Louis LeBlanc               leblanc@keyslapper.org
Fully Funded Hobbyist, KeySlapper Extrordinaire :)
http://www.keyslapper.org                     =D4=BF=D4=AC

Aphasia:
  Loss of speech in social scientists when asked
  at parties, "But of what use is your research?"

--45Z9DzgjV8m4Oswq
Content-Type: application/pgp-signature
Content-Disposition: inline

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.0.6 (FreeBSD)
Comment: For info see http://www.gnupg.org

iD8DBQE79SzJeAPWYrNkRWIRApilAJ9fSwJ8ig5VeV9D+wYB2i+8IylR5QCfQJPe
8KZ/lUlqjMI2hi2RxYZydwY=
=hbnn
-----END PGP SIGNATURE-----

--45Z9DzgjV8m4Oswq--

To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-questions" in the body of the message




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20011116151209.GA57485>