Introduction

Port forwarding is a network configuration method that directs incoming traffic from an external network to a specific device within a private network. It uses predefined rules to map external ports to internal IP addresses and ports, ensuring consistent access to services. This approach enables reliable connectivity for applications like servers, remote access, and online services.

Procedure for Testing

TCP - Method used SSH server

1)In Your client machine(LAN)you should have SSH installed
2)In router 'Add service' under Advanced > Port Forwarding
3)Select Common Service as SSH service and Service Type as TCP, then enter Server IPv4 Address where ssh server is installed, port is 22 and save.
4)Try ssh for lan client device using gateway ip address(erouter0 IP), we should able to access lan client through gateway ip using ssh service.

EX: ssh <username of lan client>@<erouter0 ip>
Password: <give lan client login password>
Able to access the Client PC

UDP - The Netcat (nc) command is a command-line utility for reading and writing data between two computer networks. The communication happens using either TCP or UDP

1)In Advance > Port Forwarding > Add Service, Common Service as other, Service Name as Netcat and Service Type as UDP, add lan clients's Server IPv4 Address 
2)In Your client machine(LAN)you have to run : nc -u -l 5000
3)From external WAN machine run nc -u 192.168.2.30 5000 (192.168.2.30 - router uplink ip address) 
4)In your client machine(LAN)run https service(In browser https://www.google.com)
5)Goto to your external network(WAN), access server of client machine(Try sending some packets to wan client). Able to see incoming traffic on ports 5000.

WEBUI

Step 1: Login to webui, from navigation -> Advanced ->Port Forwarding. Click on Add Port Forwarding.

Testing Steps (TCP and UDP)

TCP :

UDP :

In Your client machine(LAN)you have to run : nc -u -l 5000 
From external WAN machine run nc -u 192.168.2.30 5000, while client machine(LAN)run https service(In browser https://www.google.com)