On Monday, September 29, 2014, Duncan Patton a Campbell <campb...@neotext.ca>
wrote:
> My purpose here is to allow dynamic dns updates
> via nsupdate from a dhcp clients where addresses
> are subject to change. I have a solution that
> will remain stable so long as the !command
> hook in hostname.if remains stable. This is
> not as good as the dhclient.conf script interface
> as it can't exclude calls that don't change
> the interface, but hey...
>
> # more /etc/hostname.nfe0
> dhcp
> !/usr/local/sbin/dydns.sh $if
>
> more /usr/local/sbin/dydns.sh
> #!/bin/ksh
> #rdate to make sure we're sync'd with the dydns server
> echo $@ >> /tmp/ddns.log
> date >> /tmp/ddns.log
> /usr/sbin/rdate -o 192.168.1.22
> export ADDR=`ifconfig $1 | grep "inet "| cut -d ' ' -f 2`
> echo "server 192.168.1.22
> zone indx.ca
> key u32.indx.ca 7U6+9Bqymcyn21vLHIlf9DWVIYvljkn/GIMqNhg3YpaSxUDoarpBPz/J
> Pm52kWD9GG1mpewiiKsYCcarWF2wUg==
> update delete u32.indx.ca. A
> update add u32.indx.ca. 86400 A $ADDR
> send
> " | nsupdate
> exit 0
>
> where key is the shared private key produced by the output of
>
> dnssec-keygen -a HMAC-MD5 -b 512 -n USER u32.indx.ca.
>
> found in the output file Ku32.indx.ca.+157+08659.private
>
> and added to /var/named/keys.conf on the named server
> in the form
>
> key "u32.indx.ca" {
> algorithm hmac-md5;
> secret "7U6+9Bqymcyn21vLHIlf9DWVIYvljkn/GIMqNhg3YpaSxUDoarpBPz/J
> Pm52kWD9GG1mpewiiKsYCcarWF2wUg==";
> };
>
> and an entry to etc/named.conf
>
> zone "indx.ca"
> {
> ...
> allow-update
> {
> .
> .
> key u32.indx.ca ;
> .
> .
> };
> };
>
> Dhu
>
>
> On Mon, 29 Sep 2014 14:13:48 +0200
> Bruno Flueckiger <inform...@gmx.net <javascript:;>> wrote:
>
> > On 29.09.2014 13:39, Duncan Patton a Campbell wrote:
> > > On Mon, 29 Sep 2014 05:28:27 -0600
> > > Duncan Patton a Campbell <campb...@neotext.ca <javascript:;>> wrote:
> > >
> > >> /etc/dhclient.conf used to contain a
> > >>
> > >> script "tosomfile" ;
> > >>
> > >> option that could, amongst other things, be used to
> > >> set a dynamic assigned dns address to a named server.
> > >>
> > >> This functionality has been removed and I am trying to
> > >> figure out if there was some other mechanism to accomplish
> > >> this but I can't find any refs to it in the changes
> > >> between 5.1 and 5.5.
> > >>
> > >> Any info would be appreciated.
> > >>
> > >> Thanks,
> > >>
> > >> Dhu
> > >>
> > >> --
> > >> Ne obliviscaris, vix ea nostra voco.
> > >>
> > >>
> > >>
> > >
> > > I found it in the 5.3 changes..
> > >
> > > "Removed dhclient-script(8) and dhclient.conf(5) "script" directive.
> > > Do all interface and route configuration via ioctl's and routing
> > > sockets. "
> > >
> > > Unfortunately this mechanism was used for more than just routing. And
> > > without a dhclient-script to
> > > hack I don't see how a dynamic address can be updated vi the named/key
> > > mechanism.
> > >
> > > Dhu
> >
> > If your goal is to set entries in DNS for a machine which acts as DHCP
> > client there are two other possibilities I know of:
> >
> > 1. Use a reservation in DHCP server together with fixed entries in DNS
> >
> > 2. Get ISC DHCP from ports and configure it to make dynamic updates to
> > BIND
> >
> > Depending on your exact setup there may be other ways to achieve the
> > same as you did with the script.
> >
> > Bruno
> >
> >
>
>
> --
> Ne obliviscaris, vix ea nostra voco.
>
> Why not have the DHCP server update DNS?
--
J. Stuart McMurray
