WCF Service On Linux failed to communicate with Client on Windows by NetTcp

Question

There

Context: I write a demo console app -a WCF service which running on Linux by mono, and a console Client which running on Windows 7.

Linux Versoin: Both on Ubuntu and Match-box

Mono Version: 2.10.8.1(On Ubuntu) and 2.10.6(On Match-box)

Issue: The client could communicate with Service by basicHttpBinding but NOT netTcpBinding.

Exception Info: Could not connect to net.tcp://192.168.1.220/. The connection attempt lasted for a time span of 00:00:14.0408031. TCP error code 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 192.168.1.220:808.

Service Code:

class Program
 {
    static void Main(string[] args)
    { 
        try
        {
            ServiceHost sh = new ServiceHost(typeof(DynIPService.DynIPService));
            //sh.AddServiceEndpoint("DynIPServiceContract.IDynIPService", binding, "net.tcp://10.161.66.213:808");
            sh.Open();
            foreach (var ep in sh.Description.Endpoints)
            {
                Console.WriteLine("Address: {0}, ListenUri: {1}, ListenUriMode: {2} ", ep.Address, ep.ListenUri, ep.ListenUriMode);
            }
            Console.WriteLine("Service is running");               
        }
        catch (Exception ex)
        {
            Console.WriteLine("Error:" + ex.Message);
            throw;
        }
        finally
        {
           Console.ReadKey();
        }
    }
}

Service app.config(partial, here i just list the endpoints and bindings)

<services>
  <service name="DynIPService.DynIPService" behaviorConfiguration="MyServiceTypeBehaviors" >
    <endpoint address="net.tcp://127.0.0.1:808"  
              binding="netTcpBinding" bindingConfiguration="TCP_Binding"
              contract="DynIPServiceContract.IDynIPService"/>
    <endpoint address="http://127.0.0.1:123"
              binding="basicHttpBinding" bindingConfiguration="HTTP_Binding"
              contract="DynIPServiceContract.IDynIPService"/>
  </service>
</services>
<bindings>
  <basicHttpBinding>
    <binding name="HTTP_Binding">
      <security mode="None"></security>
    </binding>
  </basicHttpBinding>
  <netTcpBinding>
    <binding  name="TCP_Binding">
      <security mode="None"></security>
    </binding>
  </netTcpBinding>
</bindings> 

Client Code:

class Program
 {
    static void Main(string[] args)
    {
        //var ip = "localhost.localdomain";
        var ip = "192.168.1.220";

        //Tcp
        Binding tcpBinding = new NetTcpBinding(SecurityMode.None);
        var tcpUri = new Uri(string.Format("net.tcp://{0}:808", ip));

        //http
        Binding httpBinding = new BasicHttpBinding();  
        var httpUri = new Uri(string.Format("http://{0}:123",ip));

        EndpointAddress address = new EndpointAddress(httpUri.ToString());
        IDynIPService proxy = ChannelFactory<IDynIPService>.CreateChannel(httpBinding, address);
        var hostIP = proxy.ReadHostIp();
        Console.WriteLine(hostIP);
        Console.ReadKey();
    }
}

Answer 1

You need to use the IP address of your host machine that's publicly visible on the network if you want to connect to it remotely using net.tcp.

I just tested this on Windows and net.tcp and http actually behave differently when using 127.0.0.1: while HTTP always seem to listen on all interfaces regardless of which IP address you use on your endpoint, using a specific IP such as 127.0.0.1 makes NetTCP only listen on that particular address.

However, you can use net.tcp://localhost:<port>/<path> to make it listen on all interfaces (this was was implemented in Mono 2.10.10, see bug #275).

So either use net-tcp://localhost:808/ in your app.config to listen on all interfaces or explicitly set it to a specific IP address (that's publicly visible on the network) using net-tcp://192.168.1.200:808/ (or whatever the machine's IP address is).