ZyXEL Communications Prestige 642R Series - Manual (Page 57)

Prestige 642R Series ADSL Router
3-14 Internet Access
3.14 Single User Account
Typically, if there are multiple users on the LAN wanting to concurrently access the Internet, you will have
to lease a block of legal, or globally unique, IP addresses from the ISP.
The Single User Account (SUA) feature allows you to have the same benefits as having multiple legal
addresses, but only pay for one IP address, thus saving significantly on the subscription fees. (Check with
your ISP before you enable this feature).
The IP address for the SUA can be either fixed or dynamically assigned by the ISP. In addition, you can
designate servers, e.g., a web server and a Telnet server, on your local network and make them accessible to
the outside world. If you do not define any server, SUA offers the additional benefit of firewall protection. If
no server is defined, all incoming inquiries will be filtered out by your Prestige, thus preventing intruders
from probing your network. Your Prestige accomplishes this address sharing by translating the internal LAN
IP addresses to a single address that is globally unique on the Internet. For more information on IP address
translation, refer to RFC 1631, The IP Network Address Translator (NAT).
3.14.1 Advantages of SUA
In summary:
z
SUA is a cost-effective solution for small offices to access the Internet or other remote TCP/IP networks.
z SUA supports servers to be accessible to the outside world.
z SUA can provide firewall protection if you do not specify a server. All incoming inquiries will be
filtered out by your Prestige.
z UDP and TCP packets can be routed. In addition, partial ICMP, including echo and traceroute, is
supported.
3.14.2 Single User Account Configuration
The steps for configuring your Prestige for Single User Account are identical to the conventional Internet
access with the exception that you need to fill in two extra fields in Menu 4 - Internet Access Setup, as
shown below.