Chapter 12 Network Address Translation (NAT)

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.

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 63 Multiple Servers Behind NAT Example

A=192.168.1.33

LANWAN

B=192.168.1.34

192.168.1.1

C=192.168.1.3

D=192.168.1.36

IP Address assigned by ISP

Click Network Settings > NAT > Port Forwarding to open the following screen.

See Appendix E on page 385 for port numbers commonly used for particular services.

Figure 64 Network Settings > NAT > Port Forwarding

 

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VSG1435-B101 Series User’s Guide