ZyXEL 336M 91-003-192001B Benutzerhandbuch

ZyXEL P-336M User’s Guide

Chapter 4 Advanced

44

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.

The most often used port numbers are shown in the following table. Please refer to RFC 1700 
for further information about port numbers. 

To set the virtual server settings, click Advanced > Virtual Server to display the 
configuration screen. 

Table 16   Virtual Server: Common Services and Port Numbers

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 (Point-to-Point Tunneling Protocol)

1723