Table 7-3 Services And Port Numbers - ZyXEL Communications P-324 User Manual

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.
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. Please also refer to the Supporting CD for more examples and details on
SUA/NAT.
ECHO
FTP (File Transfer Protocol)
SMTP (Simple Mail Transfer Protocol)
DNS (Domain Name System)
Finger
HTTP (Hyper Text Transfer protocol or WWW, Web)
POP3 (Post Office Protocol)
NNTP (Network News Transport Protocol)
SNMP (Simple Network Management Protocol)
SNMP trap
PPTP (Point-to-Point Tunneling Protocol)
7.3.2 Configuring Servers Behind SUA (Example)
Let's say you want to assign ports 21-25 to one FTP, Telnet and SMTP server (A in the example), port 80 to
another (B in the example) and assign a default server IP address of 192.168.1.35 to a third (C in the
example). You assign the LAN IP addresses and the ISP assigns the WAN IP address. The NAT network
appears as a single host on the Internet.
NAT Screens

Table 7-3 Services and Port Numbers

SERVICES
Prestige 324 User's Guide
PORT NUMBER
7
21
25
53
79
80
110
119
161
162
1723
7-7