User guide

Advanced Router Settings
63
Verizon 4G LTE Broadband Router
Note: Only one computer at a time can use the triggered application.
Port Forwarding to Permit External Host Communications
Normally, your router ignores any inbound traffic that is not a response to your own outbound
traffic. Configure exceptions to this rule by using Port Forwarding.
A typical application of port forwarding can be shown by reversing the Port Triggering
example’s client-server relationship. In this case, a browser on a remote computer accesses
a web server running on a computer in your local network. Using port forwarding, tell the
router, “When you receive incoming traffic on port 80 [the standard port number for a web
server process], forward it to the local computer at 192.168.1.123.” The effects of the port
forwarding rule you have defined are outlined below:
1. The user of a remote computer opens a browser and requests a web page from
www.example.com, which resolves to your router’s public IP address. The remote
computer composes a web page request message with the following destination
information:
• Destination address: The IP address of www.example.com (your router’s address).
• Destination port number: 80, which is the standard port number for a web server
process.
The remote computer then sends this request message to your router.
2. Your router receives the request message and looks in its rules table for any rules regarding
how to handle incoming port 80 traffic. Your port forwarding rule specifies that incoming port
80 traffic is forwarded to local IP address 192.168.1.123. Therefore, your router modifies the
destination information in the request message:
The destination address is replaced with 192.168.1.123.
Your router then sends this request message to your local network.
3. Your web server at 192.168.1.123 receives the request and composes a return message
with the requested web page data, which is sent to your router.
4. Your router performs Network Address Translation (NAT) on the source IP address, and
sends this request message to the remote computer, which shows the web page from
www.example.com.
To set up port forwarding, you need to know which inbound ports the application needs.
Usually you can get this information from the publisher of the application or the relevant user
groups and news groups.