FTP PORT Command : 425 Can't open data connection

Hi I am carolene. I am working on a code which uses ftp PASV command. My job is to change it to PORT command. After doing that i am getting the error "425 Can't open data connection". Can anyone please help me on how to solve this. Its critical.

Carolene,
The error means that a data channel between the clients & server could not be opened for operations such as file transfers or directory listings. Typically in active mode the client sends a PORT command to the server & then waits for the server to connect back to it. If the server in-turn cannot connect to the client then you will run into this error. There could be several reasons for this :

1) There is a firewall on the server blocking the connection. This will prevent the outbound connection from the server to the client in response to the PORT command, in this case contact the server administrator to correctly open the outbound port on the server's firewall.

2) There is a firewall on the client blocking the connection. This will prevent the incoming connection from the server at the client. In this case configure the ports on your client side firewall.

3) The port on which the server attempts to connect to the client in response to the PORT command is not free i.e. it is being used by another process on the client's end.

4) Some client programs allow data port range to be defined specially for this purpose. I suggest you find these settings on your client program.