Ok this morning I registered a dyndns free domain name .
downloaded the linux client & installed it all was well so I thought .
today after work I got home & checked the dyndns website to see what ip it was forwarding my domain to
well turns out it was using my internal ip. so I know the update utility is working but not hte way I want it to . so off to google I go , found a few things on few sites & I put together this howto just incase you run in to the same thing I did .
Get a dyndns domain name free (register) then you need Dynamic DNS service update utility for linux it's called
ddclient
1. Grab and install either from Synaptic or
sudo apt-get install ddclient
2. Walk through the little install wizard then do it all over again:
dpkg-reconfigure ddclient
You want to make sure it runs as a service and monitors changes in ppp–something that the install wizard doesn’t cover the first time around
3. Then tweak /etc/ddclient.conf: you need to fiind the ( line use=if , if=web )change that to( use=web , web=dyndns ) with out the brakets

ok your config file should look like this
sudo gedit /etc/ddclient.conf
# Configuration file for ddclient generated by debconf
#
# /etc/ddclient.conf
pid=/var/run/ddclient.pid
protocol=easydns
use=web , web=dyndns
server=members.easydns.com
login=yournamehere
password=’password’
*.your.domain 4. Now Restart the service:
sudo /etc/init.d/ddclient force-reload
thats it should work now
if you want to see if the tool is running
sudo /etc/init.d/ddclient status
this one will show you the ip
thats it have fun