ZyXEL Communications P-2812HNU-51c User Manual page 170

Chapter 8 Network Address Translation (NAT)
Table 48 Services and Port Numbers
SERVICES
SNMP trap
PPTP (Point-to-Point Tunneling Protocol)
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 77 Multiple Servers Behind NAT Example
B=192.168.1.34
C=192.168.1.35
170
A=192.168.1.33
192.168.1.1
D=192.168.1.36
PORT NUMBER
162
1723
IP address assigned by ISP
P-2812HNU-51c User's Guide