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 AddressIn 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.
If you do not assign an IP address in Server Set 1 (default server) the Prestige discards all packets received for ports that are not specified here or in the remote management setup.
7.3.2 Port Forwarding: Services and Port NumbersThe most often used port numbers are shown in the following table. Please refer to RFC 1700 for further information about port numbers.
Table 21 Services and Port Numbers
SERVICES | PORT NUMBER |
|
|
ECHO | 7 |
|
|
FTP (File Transfer Protocol) | 21 |
|
|
SMTP (Simple Mail Transfer Protocol) | 25 |
|
|
DNS (Domain Name System) | 53 |
|
|
Finger | 79 |
|
|
HTTP (Hyper Text Transfer protocol or WWW, Web) | 80 |
|
|
POP3 (Post Office Protocol) | 110 |
|
|
NNTP (Network News Transport Protocol) | 119 |
|
|
SNMP (Simple Network Management Protocol) | 161 |
|
|
SNMP trap | 162 |
|
|
PPTP | 1723 |
|
|
Chapter 7 Network Address Translation (NAT) Screens | 86 |