ZyXEL Communications 128MH - Manual (Page 56)

Prestige 128MH PSTN Router/Hub
3-4 Chapter 3 Internet Access Application
Private IP Adresses
If your networks are isolated from the Internet (for example, only between your two branch
offices) you can assign arbitrarily 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, as shown in Table 3-2.
For this reason, it is recommended that you choose your private network number from the list
provided in Table 3-3.
Table 3-3. Private Networks IP Addresses
Private IP Addresses
10.0.0.0 - 10.255.255.255
172.16.0.0 - 172.31.255.255
192.168.0.0 - 192.168.255.255
Assigning IP Addresses
You can obtain your IP address from the IANA, from an ISP, or assigned from a private network.
If you belong to a small organization and your Internet access is through an ISP, the ISP can
provide you with the Internet addresses for your local networks. On the other hand, if you are part
of a much larger organization, you should consult your network administrator for the appropriate
IP addresses.
Note on IP Address Assignment
Regardless of your particular situation, do not create an arbitrary IP Address, always follow the
guidelines above. For more information on address assignment, refer to RFC 1597, Address
Allocation for Private Internets, and RFC 1466, Guidelines for Management of IP Address Space.