ZyXEL Communications 2864I - Manual (Page 54)

Configuring for Internet Access 41
Figure 4-1 Internet Access
IP Addresses and the Internet
Conventionally, the Internet (with a capital I) refers the large-scale
interconnected networks across the world that was originally
developed by the US Department of Defense. The Internet uses
exclusively the TCP/IP suite of protocols. The term “internet”
(lower case i), however, refers to any interconnected networks
using any protocol. An internet can be as simple as two hosts on a
LAN, or it can be as complex as the Internet itself.
Every machine on the Internet must have a unique address within
that internet. If your networks are isolated from the Internet, e.g.,
only between your two branch offices, you can assign any IP
addresses to the hosts without problems. However, the Internet
Assigned Numbers Authority (IANA) has reserved the following
three blocks of IP addresses specifically for private networks:
10.0.0.0 - 10.255.255.255
172.16.0.0 - 172.31.255.255
192.168.0.0 - 192.168.255.255