Plesk SiteBuilder: Publishing failed. Error copying files

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Posted on January 12, 2008

SiteBuilder? uses a Active FTP Connection instead of a Passive connection

Active mode AKA ( Microsoft defines as standard mode)
Standard mode FTP clients first establish a connection to TCP port 21 on the FTP server. This connection establishes the FTP command channel. The client sends a PORT command over the FTP command channel when the FTP client needs to send or receive data, such as a folder list or file. The PORT command contains information about which port the FTP client receives the data connection on. In Standard mode, the FTP server always starts the data connection from TCP port 20. The FTP server must open a new connection to the client when it sends or receives data, and the FTP client requests this by using the PORT command again.

Passive mode
Passive mode FTP clients also start by establishing a connection to TCP port 21 on the FTP server to create the control channel. When the client sends a PASV command over the command channel, the FTP server opens an ephemeral port (between 1024 and 5000) and informs the FTP client to connect to that port before requesting data transfer. As in Standard mode, the FTP client must send a new PASV command prior to each new transfer, and the FTP server will await a connection at a new port for each transfer.

so what we did was open port 20 on our firewall to allow sitebuilder to enter the server without any issue . the error we were getting when trying to access the ftp server using a browser was error “code 425 unable to open a data connection”

References – active FTP vs Passive in detail