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To: mnewton <mnewton@newland.com>
cc: hackers <hackers@FreeBSD.ORG>
Subject: Re: any one tried this 
In-reply-to: Your message of "Tue, 10 Jun 1997 10:31:03 EDT."
             <339D6527.7411@newland.com> 
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Date: Wed, 11 Jun 1997 01:43:50 +0100
From: Brian Somers <brian@awfulhak.org>
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> I have one host that has a dynamic ip address assigned each time its
> logs in. I would like to refer to that host by a domain name i.e
> xyz.zzz via a dns on another machine. 
> What i need to do is update the dns on the dns server with the
> new ip address every time that pc logs in. 
> Any body got any code to do this ?

It should be trivial.  You can pass the pseudo MYADDR variable
to a script in linkup:

MYADDR:
  delete all
  add 0 0 hisaddr
  ! /usr/local/bin/dnsupdate myhost MYADDR

And in /usr/local/bin/dnsupdate:

#! /bin/sh
host=$1
shift
read a b c d <<eof
`IFS=.; for f; do echo $f; done`
eof
cd /etc/namedb/
bak=`date +%y%m%d%H%M`
mv mynet.zone mynet.zone.$bak
sed "s/^$host[  ].*/$host IN A $a.$b.$c.$d/" mynet.zone.$bak >mynet.zone
mv mynet.rev mynet.rev.$bak
sed "s/.*[      ]$host$/$d.$c.$b.$a. IN PTR $host/" mynet.rev.$bak >mynet.rev

You'll need a small awk/perl script to up your serial number and HUP named
too.
-- 
Brian <brian@awfulhak.org>, <brian@freebsd.org>
      <http://www.awfulhak.org>
Don't _EVER_ lose your sense of humour....