@zieglerziga This is a screenshot from the link you cited with the OneMesh capable products list: I highlighted the text which points how you can use OneMesh solution. Searching further into TP-Link...

Glad to see you have sorted it out. The reason that it won't work on external port 21 maybe because your ISP filters this port. But then again using a high range external port 65000 will improve your...

Connect your root router with cable to the internet port of C6 router, then connect via Wi-Fi to the C6 router and change its operational mode to Access point as woozle has suggested - see this...

@Renato-Ribeiro I suppose you're using a Windows native FTP service. If that's the case refer to: https://www.windowscentral.com/how-set-and-manage-ftp-server-windows-10 to set it up. I would...

For FTP access to be able to work from outside your network, you need to port forward both control (port 21 TCP) and data (port 20 TCP) port. Data port depends on your FTP server implementation, port...

Wow ... that was unexpected, I am sorry @GeorKhawam. I couldn't even imagine that this is not implemented in FW of that router model.