Telkom ADSL 5100 Instruction Manual page 41

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.
The most often used port numbers are shown in the following table. Please refer to RFC 1700 for
further information about port numbers.
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)
6.3.2 Configuring Servers Behind SUA (Example)
Let's say you want to assign ports 22-25 to one server, port 80 to another and assign a default
server IP address of 10.0.0.35 as shown in the next figure.
SERVICES PORT NUMBER
7
21
25
53
79
80
110
119
161
162
1723
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