Debian as a DDNS Server

[Jerry Stuckle <jstuckle@attglobal.net>]

Hi, all,

I've done some digging around but haven't found exactly what I'm looking 
for.

Basically I have a Debian server with a static IP address (and several 
domains registered on it).

I also have a system with a dynamic domain on a completely different 
network.

What I would like to do is set up the system with the static IP address 
to be a DDNS server, ala dyndns.org or similar.

The router on the dynamic ip system can be set up to automatically 
notify someone when the ip changes, so that's not a problem.

What do I need on the static IP system to do this?  Are there packages 
for Debian, or will I need to write my own?

TIA.