ZyXEL p-2602r-d1a Manual Do Utilizador

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P-2602R/RL-DxA Series User’s Guide
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Chapter 9 Network Address Translation (NAT) Screens
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.
9.4.1  Default Server IP Address
In 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.
Note: If you do not assign a Default Server IP address, the ZyXEL Device discards 
all packets received for ports that are not specified here or in the remote 
management setup.
9.4.2  Port Forwarding: Services and Port Numbers
Use the Port Forwarding screen to forward incoming service requests to the server(s) on your 
local network. 
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 port forwarding and NAT.
Table 32   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 (Point-to-Point Tunneling Protocol)
1723