ZyXEL Communications nbg-418n Benutzerhandbuch

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Chapter 10 Network Address Translation
NBG-418N User’s Guide
106
10.5  Technical Reference
The following section contains additional technical information about the NBG-418N features 
described in this chapter.
10.5.1  NAT Port Forwarding: Services and Port Numbers
A port forwarding 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 Application screen 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: 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.
Server IP Address Type the inside IP address of the server that receives packets from the port(s) specified in 
the Port field.
Apply
Click Apply to save your changes to the Application Rules Summary table.
Reset
Click Reset to not save and return your new changes in the Service Name and Port 
fields to the previous one.
Application Rules Summary
#
This is the number of an individual port forwarding server entry.
Active
This icon is turned on when the rule is enabled. 
Name
This field displays a name to identify this rule.
Local Start/End 
Port
Public Start/End 
Port
This field displays the port number(s). 
Protocol
This is the transport layer protocol used for the service.
Server IP Address This field displays the inside IP address of the server.
Modify
Click the Edit icon to display and modify an existing rule setting in the fields under Add 
Application Rule
Click the Remove icon to delete a rule.
Table 47   
Network > NAT > Application (continued)
LABEL
DESCRIPTION