Can we send a tcp/ip message from a specific port to the client

Question

Hi All,
Iam currently trying to send a tcp/ip message to a remote machine on a specific destination port. For each tcp/ip message that iam sending iam able to figure out that the source port varies each time. So I wanted to know if it is possible to maintain a source
port for sending a tcp/ip message just like a destination Port. You can see my code below for reference:
 TcpClient client = new TcpClient();          
            client.Connect("xxx.xxx.xx.xx", 2024);
            NetworkStream clientStream = client.GetStream();
            ulong refno = GetSessionID();
            DateTime dt = DateTime.Now;
            string str = dt.Year.ToString() + "-" + dt.Month.ToString() + "-" + dt.Day.ToString() + " " + dt.Hour.ToString() + ":" + dt.Minute.ToString() +
":00";
            ASCIIEncoding encoder = new ASCIIEncoding();
            string Input2 = "<STX>Inquire<US>REF=203.163.253.55<US>RQN=" + refno.ToString() + "<US>DTE=" + str + "<US>ACI=5274<US>ACE=C<US>ACS=A<ETX>";
            string Input3 = "<STX>Inquire<US>REF=203.163.253.55<US>RQN=" + refno.ToString() + "<US>DTE=" + str + "<US>ACI=5274<US>ACE=C<US>ACS=A<ETX><CHECKSUM>";
            int length = Input2.Length;
            string hexValue = Input2.Length.ToString("X");
            string hexValue2 = length.ToString("X");
         //   string Input = "\x02 Inquire\x1F REF=203.163.253.55\x1F RQN=" + refno.ToString() + "\x1F DTE=" + str + "\x1F ACI=5274\x1F ACE=C\x1F ACS=A\x1F \x3 \\x" + hexValue2;
            string Input = "02Inquire1FREF=203.163.253.551FRQN=" + refno.ToString() + "1FDTE=" + str + "1FACI=52741FACE=C1FACS=A1F3" + hexValue2;
            byte[] buffer = encoder.GetBytes(Input);
            clientStream.Write(buffer, 0, buffer.Length);
            clientStream.Flush();
ram

Answer 1

Hi ram,
The TcpClient class has a constructor that receives an IPEndPoint instance, this is the local EndPoint.
The IPEndPoint consists of two parts, the IP address and the port to use. you can specify the local port with this parameter.
IPAddress ipAddress = Dns.GetHostEntry (Dns.GetHostName ()).AddressList[0];
int port=9999;
IPEndPoint ipLocalEndPoint = new IPEndPoint(ipAddress, port);
TcpClient tcpClientA = new TcpClient (ipLocalEndPoint);
We are trying to better understand customer views on social support experience, so your participation in this interview project would be greatly appreciated if you have time. Thanks for helping make community forums a great place.
Click
HERE to participate the survey.