Zyxel NBG-418N v2 - Инструкция по эксплуатации - Страница 106

Chapter 10 Network Address Translation

NBG-418N v2 User’s Guide

106

The following table describes the labels in this screen.

1 0 .4   NA T A p p lic a tio n Sc re e n   

Use the 

A p p lic a tio n 

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.

Port forwarding allows you to define the local servers to which the incoming services will be forwarded. 
To change your NBG-418N v2’s port forwarding settings, click 

Ne two rk >  NA T

 > 

A p p lic a tio n

. The screen 

appears as shown.

Note: If you do not assign a 

De fa ult Se rve r

IP a d d re ss

 in the 

NA T >

G e ne ra l 

screen, the NBG-

418N v2 discards all packets received for ports that are not specified in this screen or 
remote management.

Refer to 

Appendix F on page 218

 for port numbers commonly used for particular services.

Table 48   Network > NAT > General

LA BEL

DESC RIPTIO N

NAT Setup

Network Address 
Translation

Network Address Translation (NAT) allows the translation of an Internet protocol address used 
within one network (for example a private IP address used in a local network) to a different IP 
address known within another network (for example a public IP address used on the Internet). 

This field displays whether the NAT is enabled or disabled.

Default Server Setup

Enable

Click the 

Ena b le

 check box to activate the default server.

Server IP 

Address

In addition to the servers for specified services, NAT supports a default server. A default server 
receives packets from ports that are not specified in the 

A p p lic a tio n

 screen. 

If you do not assign a default server IP address, the NBG-418N v2 discards all packets received 
for ports that are not specified in the 

A p p lic a tio n

 screen or remote management.

Apply

Click 

A p p ly

 to save your changes back to the NBG-418N v2.

Reset

Click 

Re se t

 to begin configuring this screen afresh.