User's Manual

Chapter 10 Network Address Translation (NAT)
P-660RU-Tx User’s Guide
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The most often used port numbers and services are shown in Appendix D on page
219. Please refer to RFC 1700 for further information about port numbers.
Note: 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.
10.4.1 Configuring Servers Behind Port Forwarding
(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.
Figure 36 Multiple Servers Behind NAT Example
The following table summarizes the settings described in the above example.
Table 23 Multiple Servers Behind NAT Example
SERVERS PORTS
DEFAULT SERVER
IP
A FTP 21-22 192.168.1.33
B Telnet 23 192.168.1.34
C SMTP 25 192.168.1.35
A=192.168.1.33
C=192.168.1.35
B=192.168.1.34
WAN
LAN
192.168.1.1
IP Address assigned by ISP