For most people their dynamic ip address is actually a sticky dynamic ip address meaning your ip does not change often. I have had the same ip address for over two years now on my cable connection. You can however (and I do) use a dynamic DNS service so you can always have an address you can type and to connect to your network from anywhere online. The service I use is DynDNS (
http://www.dyndns.com/ ).
I hope this helps. Good luck.