70-293 Registered and Unregistered IP Address

It’s raining again, almost two entire days. The raining caused more difficult to drive especially for me since I have the astigmatism problem after I watch the monitor for almost 20 years. I still keep studying of computers even I already have 20 years experience. Today, it is a very relax day, there are only four to five persons in the office. I read the part of Registered and Unregistered IP Address, very easy concept but Microsoft used almost twenty pages to explain. My feeling is that suppose no such different, the CISCO won’t sell so many routers. Router is the key connection for registered (public) network and unregistered (private) network.