ZyXEL Communications Corporation OX253P Manuel D’Utilisation
Chapter 8 The NAT Configuration Screens
OX253P User’s Guide
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8.4 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,
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 OX253P 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 OX253P's WAN port
receives a response with a specific port number and protocol ("incoming" port),
the OX253P 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.
dynamically take turns using the service. The OX253P 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 OX253P's WAN port
receives a response with a specific port number and protocol ("incoming" port),
the OX253P 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 OX253P.
forwarding rules for the OX253P.
Figure 30 ADVANCED > NAT Configuration > Trigger Port