title: Filezilla FTP Server Fails to Retrieve Directory Listing
body: <p>I'm running Filezilla Server 0.9.45 beta to manage my server remotely.
  After setting it up, I tested connecting to it using the IP <code>127.0.0.1</code>, and it worked successfully. However, to connect to the server remotely, I port forwarded to port 21, and tried to connect using my computer's IP.</p>
  
  <pre><code>Status: Connecting to [My IP]:21...
  Status: Connection established, waiting for welcome message...
  Response:   220 Powered By FileZilla Server version 0.9.45 beta
  Command:    USER hussain khalil
  Response:   331 Password required for user
  Command:    PASS *********
  Response:   230 Logged on
  Status: Connected
  Status: Retrieving directory listing...
  Command:    CWD /
  Response:   250 CWD successful. "/" is current directory.
  Command:    PWD
  Response:   257 "/" is current directory.
  Command:    TYPE I
  Response:   200 Type set to I
  Command:    PORT 192,168,0,13,205,63
  Response:   200 Port command successful
  Command:    MLSD
  Response:   150 Opening data channel for directory listing of "/"
  Response:   425 Can't open data connection for transfer of "/"
  Error:  Failed to retrieve directory listing
  </code></pre>
  
  <p>This continues to work locally, but not when connecting remotely... How can I fix this?</p>