ZyXEL Communications MAX-306M1, User Manual

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Chapter 10 The NAT Configuration Screens
User’s Guide
114
10.4 Trigger Port
Some services use a dedicated range of ports on the client side and a dedicated
range of ports on the server side. With regular port forwarding you set a
forwarding port in NAT to forward a service (coming in from the server on the
WAN) to the IP address of a computer on the client side (LAN). The problem is
that port forwarding only forwards a service to a single LAN IP address. In order to
use the same service on a different LAN computer, you have to manually replace
the LAN computer's IP address in the forwarding port with another LAN
computer's IP address,
Trigger port forwarding solves this problem by allowing computers on the LAN to
dynamically take turns using the service. The WiMAX Modem records the IP
address of a LAN computer that sends traffic to the WAN to request a service with
a specific port number and protocol (a "trigger" port). When the WiMAX Modem's
WAN port receives a response with a specific port number and protocol
("incoming" port), the WiMAX Modem forwards the traffic to the LAN IP address of
the computer that sent the request. After that computer’s connection for that
service closes, another computer on the LAN can use the service in the same
manner. This way you do not need to configure a new IP address each time you
want a different LAN computer to use the application.
Click ADVANCED > NAT Configuration > Trigger Port to maintain trigger port
forwarding rules for the WiMAX Modem.
Figure 48 ADVANCED > NAT Configuration > Trigger Port
The following table describes the labels in this screen.
Table 36 ADVANCED > NAT Configuration > Trigger Port
LABEL DESCRIPTION
# The number of the item in this list.
Name Enter a name to identify this rule. You can use 1 - 15 printable ASCII
characters, or you can leave this field blank. It does not have to be a
unique name.
Incoming