Gets or sets the behavior of a client application's data transfer process.
Assembly: System (in System.dll)
A new value was specified for this property for a request that is already in progress.
Setting the property to true sends the "PASV" command to the server. This command requests the server to listen on a data port and to wait for a connection rather than initiate one upon receipt of a transfer command.
For a description of the behaviors that are specified using , see RFC 959, "File Transfer Protocol," Section 3.2, "Establishing Data Connections" and Section 4.1.2, "Transfer Parameter Commands," available at .
If is set to true, the FTP server may not send the size of the file, and download progress can always be zero. If is set to false, a firewall can raise an alert and block the file download.
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.