A Client for the DynDNS.org service
Copyright (C) Son Okt 21 12:40:53 MEST 2001 - now
  by Ingo Blechschmidt
  released under the Terms of the GNU General Public License

Documentation for my DynDNS.org client
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

III n http://support.dyndns.org/dyndns/clients/devel/ you can see
III precisely, how the GET-Request to http://members.dyndns.org/nic/update
III has to be. Lynx, a text-based browser, which is installed on
every Linux, can do this without user intercation. If you add the
following lines to /etc/ppp/ip-up, your IP-Address for DynDNS will
be updated every time you connect to the Internet. The client is
distributed under the Terms of the GNU General Public License, to
protect your rights.  

  # Copyright (C) Son Okt 21 12:45:47 MEST 2001 - now by Ingo
  # Blechschmidt, released under the Terms of the GNU General Public
  # License.
  
  /usr/bin/lynx -dump -auth=USERNAME:PASSWORD "http://members.dyndns.org/nic/update?system=dyndns&hostname=HOSTNAME&myip=$4" > /tmp/bab

You have simply to substitute the big written words:

  USERNAME is your username for DynDNS.org
  PASSWORD is your password
  HOSTNAME are the hosts you have registered,
           comma (,) separated, e.g. iblech.dyndns.org
  
Happy Linuxing!