New Post: PortForwading Bug

I used this little console-application and everything is working fine:

using System;
using System.Diagnostics;
using Renci.SshNet;


namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            var client = new SshClient(IP, USER, PASSWORD);
            try
            {
                client.Connect();
                Console.WriteLine("Started first client");
                Console.WriteLine(RunCmd("netstat -ant | find \"22222\""));

                var fw = new ForwardedPortLocal("127.0.0.1", 22222, "127.0.0.1", 22);
                client.AddForwardedPort(fw);
                fw.Start();

                Console.WriteLine("Started Forwarding");
                Console.WriteLine(RunCmd("netstat -ant | find \"22222\""));

                Console.WriteLine("FW started: " + fw.IsStarted);
                var fwclient = new SshClient("127.0.0.1", 22222, USER, PASSWORD);
                fwclient.Connect();

                Console.WriteLine("Started second client");
                Console.WriteLine(RunCmd("netstat -ant | find \"22222\""));

                Console.WriteLine("Press Enter to stop");
                Console.ReadLine();

                fwclient.Disconnect();
                Console.WriteLine("Stopped second Client");

                fw.Stop();
                client.RemoveForwardedPort(fw);
                Console.WriteLine("Stopped Forwarding");
                Console.WriteLine(RunCmd("netstat -ant | find \"22222\""));
                client.Disconnect();
                Console.WriteLine("Stopped first client");
                Console.WriteLine(RunCmd("netstat -ant | find \"22222\""));
            }
            catch (Exception exception)
            {
                Console.WriteLine(exception);
            }

            Console.ReadLine();
        }

        private static string RunCmd(string cmd)
        {
            var proc = new Process
            {
                StartInfo =
                {
                    FileName = "cmd.exe",
                    Arguments = "/c " + cmd,
                    UseShellExecute = false,
                    RedirectStandardOutput = true
                }
            };
            proc.Start();
            proc.WaitForExit();
            return proc.StandardOutput.ReadToEnd();
        }
    }
}

Example- Output:

Started first client

Started Forwarding
  TCP    127.0.0.1:22222        0.0.0.0:0              ABHÖREN         InHost


FW started: True
Started second client
  TCP    127.0.0.1:22222        0.0.0.0:0              ABHÖREN         InHost

  TCP    127.0.0.1:22222        127.0.0.1:51105        HERGESTELLT     InHost

  TCP    127.0.0.1:51105        127.0.0.1:22222        HERGESTELLT     InHost


Press Enter to stop

Stopped second Client
Stopped Forwarding
  TCP    127.0.0.1:22222        127.0.0.1:51105        HERGESTELLT     InHost

  TCP    127.0.0.1:51105        127.0.0.1:22222        HERGESTELLT     InHost


Stopped first client
  TCP    127.0.0.1:22222        127.0.0.1:51105        HERGESTELLT     InHost

  TCP    127.0.0.1:51105        127.0.0.1:22222        HERGESTELLT     InHost

The ListenSocket of the forwarding gets cleaned up as expected.
What does netstat -ant say after you stop your forwarding?

But just to check. When one closes a forwarded port, is it normal that this takes seconds to complete?

No.