使用 public ip 连接到服务器时出现 SocketException 'the connected party did not properly respond after a period of time' (C#)

Question

我正在尝试使用 C# 创建服务器。目前，我有两个程序，一个服务器和一个客户端，当它们都在同一台计算机上运行时，它们都可以正常工作，服务器的 TcpListener 是使用 ip 127.0.0.1 (localhost) 创建的，并且客户端连接到 ip 127.0.0.1。但是，当我尝试使用我的 public ip 连接到服务器时，客户端程序等待大约 20 秒然后我得到一个 SocketException: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond

我已经转发了我正在使用的端口（端口是2345）。我在另一台计算机上尝试了与上述相同的步骤，但仍然得到相同的结果。我在创建服务器的 TcpListener 时尝试使用 public ip 但后来我得到了 SocketException: The requested address is not valid in its context 所以我假设我应该只使用 127.0.0.1 （虽然我可能是错的，这是我第一次尝试这样的事情。

这是创建服务器的函数。

public static void RunServer()
{
    string ipStr = "";
    Console.WriteLine("Enter IP...");
    ipStr = Console.ReadLine();
    if (ipStr == "localhost")
        ipStr = "127.0.0.1";
    IPAddress ip = IPAddress.Parse(ipStr);

    int port = -1;
    Console.WriteLine("Enter port...");
    while (port == -1)
    {
        try
        {
            port = int.Parse(Console.ReadLine());
        }
        catch (FormatException)
        {
            Console.WriteLine("Please enter an integer.");
        }
    }
    Console.WriteLine("Starting server on " + ip + ":" + port);

    TcpListener tcpListener;
    try
    {
        tcpListener = new TcpListener(ip, port);
        tcpListener.Start();
    }
    catch (Exception e)
    {
        Console.WriteLine("Exception: " + e);
        Console.ReadLine();
        return;
    }

    while (true)
    {
        try
        {
            TcpClient tcpClient = tcpListener.AcceptTcpClient();

            NetworkStream networkStream = tcpClient.GetStream();

            StreamReader sr = new StreamReader(networkStream);
            string msg = sr.ReadToEnd();

            Console.WriteLine("Received message: \"" + msg + "\"");

            sr.Close();
            networkStream.Close();
            tcpClient.Close();
        }
        catch (Exception e)
        {
            Console.WriteLine("Exception: " + e);
        }
    }
}

以及创建客户端的函数。

public static void RunClient()
{
    string ip = "";
    Console.WriteLine("Enter IP...");
    ip = Console.ReadLine();

    int port = -1;
    Console.WriteLine("Enter port...");
    while (port == -1)
    {
        try
        {
            port = int.Parse(Console.ReadLine());
        }
        catch (FormatException)
        {
            Console.WriteLine("Please enter an integer.");
        }
    }

    while (true)
    {
        Console.WriteLine("Enter message...");
        string msg = Console.ReadLine();
        Console.WriteLine("Sending message: \"" + msg + "\"");

        TcpClient tcpClient;
        try
        {
            tcpClient = new TcpClient(ip, port);
        }
        catch (SocketException e)
        {
            Console.WriteLine("Could not connect to server. Connection refused.");
            Console.WriteLine("Exception: " + e);
            continue;
        }

        NetworkStream networkStream = tcpClient.GetStream();

        networkStream.Write(Encoding.ASCII.GetBytes(msg), 0, msg.Length);
        Console.WriteLine("Sent message!");

        networkStream.Close();
        tcpClient.Close();
    }
}

我认为我目前拥有的东西可以工作，但我得到的只是那个例外。

Answer 1

这是因为您计算机的防火墙阻止了连接。在防火墙的入站规则中为您正在使用的端口添加例外。

Answer 2

问题是服务器程序的行 IPAddress ip = IPAddress.Parse(ipStr); 应该是 IPAddress ip = IPAddress.Any;

使用 public ip 连接到服务器时出现 SocketException 'the connected party did not properly respond after a period of time' (C#)

SocketException 'the connected party did not properly respond after a period of time' when connecting to server using public ip (C#)

c#

network-programming

system.net

system.net.sockets