ZyXEL Communications ZyWALL5UTM 4.0 User Manual

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ZyWALL 5/35/70 Series User’s Guide
Chapter 7 WAN Screens
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7.9  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 37   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.
7.10  DNS Server Address Assignment
Use DNS (Domain Name System) to map a domain name to its corresponding IP address and 
vice versa, for instance, the IP address of www.zyxel.com is 204.217.0.2. The DNS server is 
extremely important because without it, you must know the IP address of a computer before 
you can access it. 
The ZyWALL can get the DNS server addresses in the following ways.
Allow between 
WAN and WLAN
Select this check box to forward NetBIOS packets from the WLAN to the WAN and 
from the WAN to the WLAN. 
Clear this check box to block all NetBIOS packets going from the WLAN to the WAN 
and from the WAN to the WLAN.
Allow Trigger Dial Select this option to allow NetBIOS packets to initiate calls.
Apply
Click Apply to save your changes back to the ZyWALL.
Reset
Click Reset to begin configuring this screen afresh.
Table 36   WAN Route (continued)
LABEL
DESCRIPTION