Chapter 10 Network Address Translation

Table 47 Network > NAT > Application (continued)

LABEL

DESCRIPTION

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

This field displays the port number(s).

Port

 

Public Start/End

 

Port

 

 

 

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.

 

 

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.

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NBG-418N User’s Guide