I forgot to show the code I'm using right now. Here it is.

Dim s As Socket
Dim ep As IPEndPoint
Dim ipAddress1 As String
Dim port as Int32
ep = New IPEndPoint(Dns.Resolve(ipAddress1).AddressList( 0 ), port)
s = New Socket(ep.AddressFamily, SocketType.Stream, ProtocolType.Tcp)
s.Connect(ep)

Hi Humberto,

As you're probably aware, using active mode means that rather than setting
up a Socket to read from a port that is determined by the FTP Server, and
sent to you as a reply to the "PASV" command, you decide what port to use,
and use the "PORT" command to tell the server what port to send or receive
on.

The IP address is not a problem, I'm sure, so first, of course, you need to
pick a port to use. The FTP standard defines this as an "ephemeral" port.
There is some disagreement concerning what ports are "ephemeral.," but your
best bet is to use a port between 49152 through 65535. These are defined by
IANA as the "Dynamic or Private" ports, which cannot be registered. See
http://www.iana.org/assignments/port-numbers for more information.

However, there is a problem here, as Windows by default only allows use of
ports 102 - 5000. While this can be reconfigured through the System
Registry, you probably don't want to do that unless necessary, especially if
you expect this app to run on any machine. The good news is, your port can
be picked for you.

Socket socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream,
ProtocolType.Tcp);

// Let the port be selected for you
IPHostEntry localHostEntry = Dns.GetHostEntry(Dns.GetHostName());
IPEndPoint localEndPoint = new IPEndPoint(localHostEntry.AddressList[0], 0);
socket.Bind(localEndPoint);
// Queue up to 5 connections
socket.Listen(5);

Next, you need to construct the PORT command. First you need the IP address
and Port number that the Socket is bound to:

int port = ((IPEndPoint)socket.LocalEndPoint).Port;
IPAddress ipAddress = ((IPEndPoint)socket.LocalEndPoint).Address;

Next, you need to construct your PORT command and send it via your Control
Socket. The format is:

h1,h2,h3,h4,p1,p2

The first four are easy. They are the 4 octets of your IPAddress. The 2 port
numbers are 2 bytes that make up the port number. Fortunately, you can get
all of these from the IPAddress in your IPEndPoint. Just use the
IPAddress.GetAddressBytes method to do so:

byte[] addressBytes = localEndPoint.Address.GetAddressBytes();
StringBuilder command = new StringBuilder("PORT ");
for (int i = 0; i < addressBytes.Length; i++)
{
   command.Append((short)bytes[i]);
   command.Append(",");
}

Then you just send the command on the Control Socket, and wait for the 200
repsonse.