ZyXEL p-334 Manuel D’Utilisation

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Prestige 334 User’s Guide
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Chapter 7 Network Address Translation (NAT) Screens
You may enter a single port number or a range of port numbers to be forwarded, and the local 
IP address of the desired server. The port number identifies a service; for example, web 
service is on port 80 and FTP on port 21. In some cases, such as for unknown services or 
where one server can support more than one service (for example both FTP and web service), 
it might be better to specify a range of port numbers. You can allocate a server IP address that 
corresponds to a port or a range of ports.
Many residential broadband ISP accounts do not allow you to run any server processes (such 
as a Web or FTP server) from your location. Your ISP may periodically check for servers and 
may suspend your account if it discovers any active services at your location. If you are 
unsure, refer to your ISP.
7.3.1  Default Server IP Address
In addition to the servers for specified services, NAT supports a default server IP address. A 
default server receives packets from ports that are not specified in this screen
7.3.2  Port Forwarding: Services and Port Numbers
A NAT server set is a list of inside (behind NAT on the LAN) servers, for example, web or 
FTP, that you can make accessible to the outside world even though NAT makes your whole 
inside network appear as a single machine to the outside world. 
Use the SUA Server page to forward incoming service requests to the server(s) on your local 
network. You may enter a single port number or a range of port numbers to be forwarded, and 
the local IP address of the desired server.  The port number identifies a service; for example, 
web service is on port 80 and FTP on port 21. In some cases, such as for unknown services or 
where one server can support more than one service (for example both FTP and web service), 
it might be better to specify a range of port numbers.  
In addition to the servers for specified services, NAT supports a default server. A service 
request that does not have a server explicitly designated for it is forwarded to the default 
server. If the default is not defined, the service request is simply discarded.
Note: If you do not assign a Default Server IP Address, the 
Prestige discards all packets received for ports that are not 
specified in this screen or remote management.
Note: Many residential broadband ISP accounts do not allow 
you to run any server processes (such as a Web or FTP server) 
from your location. Your ISP may periodically check for servers 
and may suspend your account if it discovers any active 
services at your location. If you are unsure, refer to your ISP.