CentOS - Jan 2010 - Setting up a Dynamic DNS server listening to dyndns protocol

Greetings,

Somehow my googling skills are not upto mark.

Pray can somebody point out resources which works like GnuDIP but
listens to Dyndns protocol as one of the proprietary gateways can talk
only in dyndns or ddo.

Basic scenario: one Private DNS server updating itself using data
thrown at it by various known adsl based client (gateway device) using
dyndns / ddo protocol.

This server will be on a public IP and updates should happen only by
those clients (gateway device). Not much can be done on the device as
it is live and I can't change device.

any help will be appreciated

Regards,

Rajagopal