ZyXEL Communications prestige 314 plus User Manual

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Prestige 314 PLUS Broadband Sharing Gateway with 4-Port Switch 
Internet Access  
3-3 
Network Address Translation (NAT) feature of the Prestige. The Internet Assigned Number Authority 
(IANA) reserved this block of addresses specifically for private use; please do not use any other number 
unless you are told otherwise. Let’s say you select 192.168.1.0 as the network number; which covers 254 
individual addresses, from 192.168.1.1 to 192.168.1.254 (zero and 255 are reserved). In other words, the first 
three numbers specify the network number while the last number identifies an individual workstation on that 
network. 
Once you have decided on the network number, pick an IP address that is easy to remember, e.g., 
192.168.1.1, for your Prestige, but make sure that no other device on your network is using that IP. 
The subnet mask specifies the network number portion of an IP address. Your Prestige will compute the 
subnet mask automatically based on the IP address that you entered. You don’t need to change the subnet 
mask computed by the Prestige unless you are instructed to do otherwise. 
3.1.4 Private IP Addresses 
Every computer on the Internet must have a unique IP address. 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: 
Table 3-2 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.