unable to connect to another computer in C#

Question

hello guyz i have made a bare bone program in C# that simply sends a message from server to client.

Now i have successfully tested both programs running on the same machines. However when i attempt to connect 2 different computers on different networks it sends me the unable to connect message.

Here the server code.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Net;
using System.IO;
using System.Net.Sockets;

namespace chat_client_console
{
    class Program
    {
        static TcpListener listener;
        static void Main(string[] args)
        {
            /*
            string name = Dns.GetHostName();
            IPAddress[] address = Dns.GetHostAddresses(name);


            foreach(IPAddress addr in address)
            {
                Console.WriteLine(addr);
            }

            Console.WriteLine(address[2].ToString());*/
            Console.WriteLine("server");
            listener = new TcpListener(IPAddress.Any, 2055);

            listener.Start();

            Socket soc = listener.AcceptSocket();
            Console.WriteLine("Connection successful");
            Stream s = new NetworkStream(soc);

            StreamReader sr = new StreamReader(s);
            StreamWriter sw = new StreamWriter(s);

            sw.AutoFlush = true;
            sw.WriteLine("A test message");
            sw.WriteLine("\n");
            Console.WriteLine("Test message delivered. Now ending the program");

            /*
            string name = Dns.GetHostName();
            Console.WriteLine(name);
            //IPHostEntry ip = Dns.GetHostEntry(name);
            //Console.WriteLine(ip.AddressList[0].ToString());
            IPAddress[] adr=Dns.GetHostAddresses(name);
            foreach (IPAddress adress in adr)
            {
                Console.WriteLine(adress);
            }
            */
            Console.ReadLine();
        }
    }
}

and here the client code.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;
using System.Net.Sockets;

namespace chat_client_console_client
{
    class Program
    {
        static void Main(string[] args)
        {
            string host_ip_address;
            Console.WriteLine("Enter server ip address");
            host_ip_address=Console.ReadLine();
            string display;
            TcpClient client = new TcpClient(host_ip_address, 2055);
            Stream s = client.GetStream();
            Console.WriteLine("Connection successfully received");

            StreamWriter sw = new StreamWriter(s);
            StreamReader sr = new StreamReader(s);
            sw.AutoFlush = true;
            /*while (true)
            {

                display = sr.ReadLine();

                if (display == "")
                {
                    Console.WriteLine("breaking stream");
                    break;
                }

            }*/

            display = sr.ReadLine();

            Console.WriteLine(display);
            Console.ReadLine();
        }
    }
}

now when i enter the 127.0.0.1 in the client program it successfully connects to the server and the message is received.

However when i enter my external ip address in the client program running on another computer i am unable to connect.

Suggestions are required in this matter.

Thank you.

Answer 1

您可以在客户端计算机中使用Wireshark并查找任何tcp数据包，以确保将消息发送到服务器。