ZyXEL Communications P-320W, User Manual

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P-320W User’s Guide
Chapter 5 WAN 81
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H A P T E R
5
WAN
This chapter describes how to configure WAN settings.
5.1 WAN IP Address Assignment
Every computer on the Internet must have a unique IP address. If your networks are isolated
from the Internet, for instance, 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.
Table 29 Private IP Address Ranges
10.0.0.0 - 10.255.255.255
172.16.0.0 - 172.31.255.255
192.168.0.0 - 192.168.255.255
You can obtain your IP address from the IANA, from an ISP or have it assigned by 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: Regardless of your particular situation, do not create an arbitrary IP address;
always follow the guidelines above. For more information on address
assignment, please refer to RFC 1597, Address Allocation for Private Internets
and RFC 1466, Guidelines for Management of IP Address Space.
5.2 IP Address and Subnet Mask
Similar to the way houses on a street share a common street name, so too do computers on a
LAN share one common network number.
Where you obtain your network number depends on your particular situation. If the ISP or
your network administrator assigns you a block of registered IP addresses, follow their
instructions in selecting the IP addresses and the subnet mask.