Here is a quick how to install dns updater on ubuntu server.
First login as root and issue the following command.
The package will install and then prompt you to select the service you use.
You will then be prompted to enter the account username you have with the updater service.
Then enter the password used with the account.
At the next screen choose from list, if you entered user & password correctly you will see your hostname after this.
Select your dns address then ok to continue.
That's it the default installed settings are good to go, but should you need to change anything login to your server as root and issue this command.
You will see simillar to the screens above but with extra options.
Have Fun.