连接到通过Ngrok暴露的TCPLISTENER时的超时

Question

我有两个工作服务作为TCP客户端和服务器。我正在尝试将单个字节从客户端发送到服务器，并使用确认字节的服务器响应。

当两者在本地运行时，一切都起作用，但是当我通过Ngrok公开服务器时，客户端会暂停而无法连接。 NGrok诊断没有报告任何问题。

使用常规插座代替TCP包装器会导致相同的例外。

最小的复制，步骤和例外。

服务器

using Serilog;
using System.Net;
using System.Net.Sockets;

namespace TcpServer
{
    public class ServerService : BackgroundService
    {
        private readonly ILogger<ServerService> _logger;

        public ServerService(ILogger<ServerService> logger)
        {
            _logger = logger;
        }

        protected override Task ExecuteAsync(CancellationToken stoppingToken)
        {
            var acknowledgement = new byte[] { 2 };
            var receiveBuffer = new byte[1];
            TcpClient? client = null;
            NetworkStream? stream = null;

            return Task.Run(() =>
            {
                while (!stoppingToken.IsCancellationRequested)
                {
                    try
                    {
                        var server = new TcpListener(new IPAddress(new byte[] { 127, 0, 0, 1 }), 2222);
                        server.Start();
                        Log.Debug("Listening on endpoint {Endpoint}", server.LocalEndpoint);

                        client = server.AcceptTcpClient();
                        Log.Debug("Connection request accepted");

                        var stream = client.GetStream();
                        var received = stream.ReadByte();
                        Log.Information("Message {Message} received", received);

                        stream.Write(acknowledgement, 0, 1);
                        Log.Debug("Acknowledgement sent");

                        stream.Close();
                        client.Close();
                    }
                    catch (Exception ex)
                    {
                        stream?.Close();
                        client?.Close();
                        Log.Error("Exception {Exception} occurred", ex);
                    }
                   
                    stream?.Close();
                    client?.Close();
                    Log.CloseAndFlush();
                    stoppingToken = new CancellationToken(true);
                }
            }, stoppingToken);
        }
    }
}

客户端

using Serilog;
using Serilog.Core;
using System.Net;
using System.Net.Sockets;

namespace TcpClient
{
    public class ClientService : BackgroundService
    {
        private readonly ILogger<ClientService> _logger;
        private readonly IConfiguration _configuration;

        public ClientService(ILogger<ClientService> logger, IConfiguration configuration)
        {
            _logger = logger;
            _configuration = configuration;
        }

        protected override Task ExecuteAsync(CancellationToken stoppingToken)
        {
            var messageToSend = new byte[] { 1 };
            var receiveBuffer = new byte[1];
            System.Net.Sockets.TcpClient? client = null;
            NetworkStream? stream = null;

            var noTries = 5;

            return Task.Run(() =>
            {
                while (!stoppingToken.IsCancellationRequested &&
                       noTries-- > 0)
                {
                    try
                    {
                        client = new System.Net.Sockets.TcpClient("localhost", 2222);
                        Log.Debug("Connected to the remote server");

                        stream = client.GetStream();

                        stream.Write(messageToSend);
                        Log.Information("Message sent");

                        stream.Read(receiveBuffer);
                        Log.Debug("Acknowledgement received");
                        noTries = 0;
                    }
                    catch (Exception ex)
                    {
                        stream?.Close();
                        client?.Close();
                        Log.Error("Exception {Exception} occurred", ex);
                    }
                }

                stream?.Close();
                client?.Close();
                Log.CloseAndFlush();
            }, stoppingToken);
        }
    }
}

步骤

1. 运行服务器服务。
2. 启动NGrok并执行命令NGROK TCP 2222。
3. 将给定的主机名和端口用作客户端参数。
4. 运行客户。

例外（重复）

[13:19:42 ERR] Exception System.Net.Internals.SocketExceptionFactory+ExtendedSocketException (10060): 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.