"Humberto Alvarez" <humalva***@yahoo.com> wrote in message
news:OeeBZHYZGHA.4936@TK2MSFTNGP05.phx.gbl...
> Hi
>
> Does someone know how to create a socket to connect to a ftp server that
> does not accept passive connections?
>
> I need to modify my ftp class (wich works pretty good in passive mode) to
> connect to the ftp in active mode.
>
> Thanks a lot for the help
>
> Humberto
>

"Humberto Alvarez" <humalva***@yahoo.com> wrote in message
news:OeeBZHYZGHA.4936@TK2MSFTNGP05.phx.gbl...
> Hi
>
> Does someone know how to create a socket to connect to a ftp server that
> does not accept passive connections?
>
> I need to modify my ftp class (wich works pretty good in passive mode) to
> connect to the ftp in active mode.
>
> Thanks a lot for the help
>
> Humberto
>

"Kevin Spencer" <kevin@DIESPAMMERSDIEtakempis.com> wrote in message
news:eJpng3ZZGHA.3880@TK2MSFTNGP04.phx.gbl...
> 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.
>
> --
> HTH,
>
> Kevin Spencer
> Microsoft MVP
> Professional Numbskull
>
> Hard work is a medication for which
> there is no placebo.
>
>
> "Humberto Alvarez" <humalva***@yahoo.com> wrote in message
> news:OeeBZHYZGHA.4936@TK2MSFTNGP05.phx.gbl...
>> Hi
>>
>> Does someone know how to create a socket to connect to a ftp server that
>> does not accept passive connections?
>>
>> I need to modify my ftp class (wich works pretty good in passive mode) to
>> connect to the ftp in active mode.
>>
>> Thanks a lot for the help
>>
>> Humberto
>>
>
>