Re: [ILUG] Dynamically choosing smtp server

From: Conor Daly (conor.daly at domain met.ie)
Date: Tue 17 Sep 2002 - 11:03:50 IST


On Tue, Sep 17, 2002 at 09:56:24AM +0100 or thereabouts, Kenn Humborg wrote:
>
> Are you running a DNS server on the dialup box? If so, create
> a zone file for some fake domain (say conor-daly.). Then
> put a single CNAME record in this zone for outgoing-smtp.conor-daly.
> Your ip-up.local script then rewrites this zone file to bump up
> the zone serial number and point this CNAME to the correct SMTP
> server name. Then it does "service named reload".
 
Do I need to have the smtp servers explicitly numbered in the zone file or
can I have a

smtphost CNAME smtp.iol.ie

in the zone file instead?

> Mind you, a simple perl one-liner (which someone else can provide)
> that modified sendmail.cf in-place it probably the simplest.
> Note that, in a lot of cases, you don't need to restart sendmail
> to pick up changes to the .cf file. But to be safe, stick a
> "service sendmail reload" in your ip-up.local after modifying
> sendmail.cf.

or a

sed -e 's/DSsmtp:.*$/DSsmtp:<current.smtp.server>/' sendmail.cf > send.cf &&
mv send.cf sendmail.cf

looks like working. Mind you, I thought I could have sed modify the file in
place also...

Since I'm queuing mail and flushing with

sendmail -q

rather than running in daemon mode, I shouldn't need to

service sendmail reload

though I am running sendmail on my internal smtp server but in queuing mode
only. Arrgh, I'm getting confused now!

Conor

-- 
Conor Daly 
Met Eireann, Glasnevin Hill, Dublin 9, Ireland
Ph +353 1 8064276 Fax +353 1 8064247
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