ZyXEL Communications VMG8825-B Series User Manual page 182

Chapter 11 Network Address Translation (NAT)
Table 69 Services and Port Numbers
SERVICES
SNMP (Simple Network Management Protocol)
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 98 Multiple Servers Behind NAT Example
VMG8825-B Series User's Guide
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PORT NUMBER
161
162
1723
DSL
IP Address assigned by ISP