FileZilla FTP to public

Question

Today I was trying to set up an FTP server for my friend and myself. Server is in my home so I have no problem accessing it locally, but I am unable to open it to public. For my server configuration it is FileZilla server running on Windows 7 machine. I have disabled all firewalls so nothing is blocking it for now and I am able to connect to it in my local network.

What I have tried when it comes to opening it to local (on MikroTik router):  I have created a firewall NAT rule to forward from my public IP address and port 776 to the server IP address on port 21 and what I get from FileZilla when trying to connect from external network:

Status: Logged in
Status: Retrieving directory listing...
Command: PWD
Response: 257 "/" is current directory.
Command: TYPE I
Response: 200 Type set to I
Command: PASV
Response: 227 Entering Passive Mode (31,134,50,169,198,229)
Command: MLSD
Error: The data connection could not be established: ECONNREFUSED - Connection refused by server
Response: 425 Can't open data connection for transfer of "/"
Error: Failed to retrieve directory listing

So as I see I am able to connect but can't actually read files. I know that there is this 'Passive Mode' problem, but from what I have read it is occurring when trying to connect, so it is not on me anymore? Correct me if I am wrong please.

I was also using this site to test for everything but it showed errors. I am new to this kind of stuff and not very skilled when it comes to setting up connections.

This question [from ServerFault] is talking about this stuff too, but I am unable to make it work. If anyone can explain to me step by step what do I do, please.

EDIT:

FileZilla output:

Command: MLSD
Error:    The data connection could not be established: ECONNREFUSED - Connection refused by server
Response: 425 Can't open data connection for transfer of "/"
Error:    Failed to retrieve directory listing

My NAT rule that forwards from my router IP and port 776 to server local port 21:

NAT rules that I have added to accept inbound and out traffic:

Answer 1

The problem is you are only opening port 21, and you need to open a bunch of others:

• Outbound: TCP ports 1025 and above.
• Inbound: TCP port 21 and TCP ports 1025 and above.

Try this and should work ok.

However that's a HUGE range of ports. You can limit your exposure by configuring a lower range of ports in the filezilla server, let's say from (50,100 to 51,100):

• Open up the FileZilla GUI on your server.
• Click on the top menu Edit -> Settings.
• From the tree menu click on Passive mode settings.
• Now make sure the checkbox Use custom port range is checked and enter 50100 in the first box a and 51100 in the second.

After that, make the same changes in your firewall, and you should be ok.