Maurits wrote:
If the port is 2121, change the URI to be ftp://ftp.example.com:2121/dir/file.ext


i use this:

string uri = "ftp://127.0.0.1/";
UriBuilder newUriPort = new UriBuilder(uri);
newUriPort.Port = 20;
uri = newUriPort.Uri.ToString(); // ftp://127.0.0.1:20/