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Chapter 18 Network Address Translation (NAT) Screens
ZyWALL 2WG User’s Guide
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If you do not assign a
Default Server
IP address, the ZyWALL discards all
packets received for ports that are not specified here or in the remote
management setup.
Port Forwarding: Services and Port Numbers
The ZyWALL provides the additional safety of the DMZ ports for connecting your publicly
accessible servers. This makes the LAN more secure by physically separating it from your
public servers.
Use the
Port Forwarding
screen to forward incoming service requests to the server(s) on your
local network.
The most often used port numbers are shown in the appendix on
. Please refer to
RFC 1700 for further information about port numbers.
18.4.1 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 242
Multiple Servers Behind NAT Example
NAT and Multiple WAN
The ZyWALL has two WAN interfaces. You can configure port forwarding and trigger port
rule sets for the first WAN interface and separate sets of rules for the second WAN interface.