Dynamic DNS makes it much easier to access a server from the Internet because you
can type the name in the Internet browser. Otherwise, you must know the IP address
that the ISP assigned, which typically changes.
How the Router Implements a Port Forwarding Rule
The following sequence shows the effects of a port forwarding rule:
1. When you type the URL www.example.com in your browser, the browser sends a
web page request message with the following destination information:
•
Destination address. The IP address of www.example.com, which is the address
of your router.
•
Destination port number. 80, which is the standard port number for a web server
process.
Your router receives the message and finds your port forwarding rule for incoming
port 80 traffic.
2. The router changes the destination in the message to IP address 192.168.1.123 and
sends the message to that computer.
3. Your web server at IP address 192.168.1.123 receives the request and sends a reply
message to your router.
4. Your router performs Network Address Translation (NAT) on the source IP address
and sends the reply through the Internet to the computer or mobile device that sent
the web page request.
Manage Port Triggering for Services and
Applications
Port triggering is a dynamic extension of port forwarding that is useful in these cases:
•
An application must use port forwarding to more than one local computer (but not
simultaneously).
•
An application must open incoming ports that are different from the outgoing port.
With port triggering, the router monitors traffic to the Internet from an outbound “trigger”
port that you specify. For outbound traffic from that port, the router saves the IP address
of the computer that sent the traffic. The router temporarily opens the incoming port
or ports that you specify for your port triggering service or application and forwards
that incoming traffic to that destination.
User Manual
194
Manage and Customize Internet
Traffic Rules for Ports
XR500 Nighthawk Pro Gaming Router
