[Hilo] When Hilo is used as a FTP server, why I always fail to connect it with a FTP client?
Answer: The IP of the Hilo has to be routable and public one.
If your Hilo has a private IP, it will be seen only by a PC on this private network.
If your private network is linked to the internet by a gateway, you have to redirect the port number 21 to the private IP of your Hilo. It is the only way to access to the Hilo by the Internet. You will probably need a static IP.
It’s same for when Hilo used as TCP/UDP server.