When organizing a local network of several computers at home, a problem may arise that you will not be able to access ftp servers operating in active mode. This is due to the fact that the local network has only one external ip-address, which belongs to the router - the device used as a gateway (computer or router). In order to correct the situation, port forwarding (forwarding, forwarding) is done. If you are using a router as a gateway, do the following:
Enter the router settings. For this, in the address bar of the browser, enter its address, for example, 192.168.1.1. After that, you will see the router's web interface asking for a username and password. The word admin is often used as such (check the device documentation). Please log in.
Set up a port forwarding rule. To do this, find the desired page in the settings of the router. In different models of routers, it may have a different name: Advanced - Port Forwarding, NAT Setting - Virtual Server or "Port Forwarding"
Enter the computer name or its ip-address, port range in the table, select the protocol. The ip-address can be found by typing ipconfig in the command line (start button -Run, enter cmd). Save your changes. Reboot your router.