is about as good as any other dynamic-dns service offered.
Navigate to the website below and click on the link in the upper right hand corner to sign up for the service. Make sure you have read the FAQ and other information provided.
Choose an appropriate name for your site, and if it is available, it will be prepended to dyndns.org, as in ilandis.dyndns.org.
Next, you will have to choose an "update client". Make sure you choose a client for linux. Read up about the various clients offered. The link for them is at the bottom of the page below "More Info:"
or go there via this link:
The ddclient seems to come highly recommended. It is in tar.gz format.
At the bottom of this page you'll see a link for more 3rd party clients, which will also link you to their homepages, with possible installation and configuration instructions.
My client runs on my winbox on the network, so I cannot help you with setting the client up in Fedora.
Hope it helps a bit.
P.S. If you have the Westell Versalink 327W, it will support dynamic updates. Not sure about the other models.