ZyXEL Communications Prestige 28641, User Manual

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42 Configuring for Internet Access
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