Chapter 10 Network Address Translation (NAT)
10.4 The Virtual Server Screen
LAN computers usually have
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.
The most often used port numbers and services are shown in Appendix D on page 205. Please refer to RFC 1700 for further information about port numbers.
"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.
10.4.1Configuring Servers Behind Port Forwarding (Example)
Let's say you want to assign ports
Figure 36 Multiple Servers Behind NAT Example
A=192.168.1.33 LAN |
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B=192.168.1.34 |
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192.168.1.1
C=192.168.1.35
IP Address assigned by ISP
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 | 192.168.1.33 | |
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B | Telnet | 23 | 192.168.1.34 |
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C | SMTP | 25 | 192.168.1.35 |
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