We Keep Coding

'No connection could be made because the target machine actively refused it'

I am working on a 'Smart Device Project' using .Net Framework 3.5. I am trying to connect to some Java SOAP services on a remote server.
In order to do that, I added 'Web References' to my project.
When I try to call my web service I get a WebException 'Unable to connect to the remote server' with the inner exception being 'No connection could be made because the target machine actively refused it'.
I searched quite a lot on the Web and StackOverflow and found a lot of ASP configuration and 'Unavaliable port' answers, but as I have another application using the exact same Service successfully, I can't get why the new one isn't getting through (It did sometimes through my tests so I suppose my client implementation isn't that bad)
I tried to look if there was some connection issue on the port by using some TcpClient:
System.Net.Sockets.TcpClient client = new System.Net.Sockets.TcpClient();
try
{
client.Connect("myServerName", 8087);
MessageBox.Show("Success");
} catch (Exception ex)
{
MessageBox.Show("Failure");
}
finally
{
client.Close();
}
This connection succeed.
Here is a sample on how I call my WebService:
WSServiceExtended srv = new WSServiceExtended();
srv.Proxy = new System.Net.WebProxy();
ServeurWSI wsi = new ServeurWSI();
srv.Url = "http://myServerName:8087/myServerApp/services/myService";
wsr = srv.login(wsi);
The service is called 'Extended' because I overrided the auto-generated one in order to add Cookie managment since I am using the Compact Framework. Following the sample in this thread:
https://social.msdn.microsoft.com/Forums/en-US/34d88228-0b68-4fda-a8cd-58efe6b47958/no-cookies-sessionstate-in-compact-framework?forum=vssmartdevicesvbcs
EDIT:
I made some new tests with the Web references and got it to work.
When I add the Web Reference, I have to put some Url to the Web Service. When I set it with the actual hostname instead of the 'localhost' everything is fine.
But then, since I set it manually to the real address just before the call, it shouldn't matter
srv.Url = "http://myServerName:8087/myServerApp/services/myService";
EDIT2:
I might have forgotten some specifics about my environnement.
The Web Services are exposed on my computer on some Tomcat Server.
The application I am working on is also developped on this computer (That's why I can add Web References by putting 'localhost' in the address)
The application is then deployed on a distant device (Windows CE) that will make calls the Web Services through WIFI (There, localhost wouldn't work then)
I tried calling the Web services from other computers successfully.
I'm beginning to think that there might be some differential between the called Url and the one that is set, otherwise, how would I have a difference in behaviour such as the one described in the first edit?
EDIT3:
Well..Seems like it's not a network issue but a .Net compact framework (usage?) issue...
The Url property of the Web Service implementation is simply ignored and the one in the Reference.cs is used in place.
If someone had some idea on how I could troubleshot this, I would really appreciate it.

That error means that you reached a server and the server said "no way". So you're either hitting the wrong server or the wrong port.
I find the telnet client is useful for testing stuff like this. From the command line, you can do:
telnet [servername] [port]
So something like:
telnet myServerName 8087
If it goes to a blank screen, then it connected successfully. If it does not connect, it'll tell you.
The telnet client is no longer installed by default in Windows 7+, so you'll have to install it. See here for instructions: https://technet.microsoft.com/en-ca/library/cc771275
If the connection does open, you could paste in an actual HTTP request to see what happens. A simple GET would look something like this:
GET /myServerApp/services/myService HTTP/1.1
Host: myServerName:8087

One reason for this error can be that the service binds to only a certain IP address. It could well be that the service only listens on the IP that is assigned to the host name, but not on the localhost IP (127.0.0.1).
For example:
If the host myServerName has the public IP 192.168.0.1, your service can choose to listen on all IPs assigned to the host (sometimes specifying 0.0.0.0), or it can specifically listen on 192.168.0.1 only. In that case you will not be able to connect through 127.0.0.1, because the service simply doesn't listen on that IP.
You can "use" this inverse of this feature to make a service accessible only to local clients, not on the public IP-Address, by listening on 127.0.0.1 only, but not on the public IP. This is sometimes used on Linux for example to make MySQL only accessible on the host itself.

I was starting to forget this post but I finally found the problem that was messing things up and it has nothing to do with programmation.
I was doing the calls while the device was connected to the computer via the 'Windows Mobile Device Center' allowing to access the device from Windows.
While connected, the host provided is ignored and all calls on the specified port are handled by the connected computer.
Disconnecting the device allows to communicate properly...

Get connection to Trace32 running on Host-PC using t32apinet.dll on Remote-PC

I'm try to use t32apinet.dll on host V (Win7 embedded 32bit) to connect with host W (Win 7 64bit).
TRACE32 on host W is already configured in config.t32 to accept a connection:
; Remote Control Access
RCL=NETASSIST
PORT=20000
PACKLEN=1024
TRACE32 is running on W while I try to config the driver and to establish the connection from V as follows:
T32 = new T32API();
T32.Config("NODE=", "192.168.100.2");//all Config returns 0 (no errors)
T32.Config("PACKLEN=", "1024");
T32.Config("PORT=", "20000");
T32.Init();//returns -1
//T32.Attach((int) T32API.Device.ICD);
On W I see incoming packages on port 20000 when Init() is executed on V.
Any ideas why Init() return with error?
Additional info regarding comments bellow:
I'm using T32Start-Tool to start Trace32, where using of API Port is activated and port value: 20000 is set
calling t32remtest.exe 192.168.100.2 port=20000 on remote PC returns:
error initializing TRACE32
error initializing TRACE32

The minimum viable settings block for enabling the Remote API port of TRACE32 in your configuration file is:
RCL=NETASSIST
PORT=20000
Please make sure to include an empty line before and after the block and that the correct TRACE32 configuration file is selected during start-up.
If you are using the T32Start utility to start TRACE32, the configuration file gets dynamically generated and is not necessarily identical with the default one config.t32.

although I saw the incoming packages in the sniffer there was no reactions from TRACE32.
The problem was that Windows recognized that network as public and blocked packages on the application level. Due to specific local IT policies the solution for me is to create a rule in windows firewall to explicitly allow communication on UDP port 20000:
screen with settings for new inbound rule in Win firewall

SignalR client won't connect using OWIN Self Host in Azure Worker Role

I have an Azure Cloud Service with a worker role that starts an OWIN web app on startup, which uses SignalR.
Separately, I have a console project that uses the SignalR client library to connect to this worker role and listen for events.
Everything is working when I run the client and the service locally using the Azure emulators.
When I publish the cloud service and point the console application to it and try to connect, I get the following in the SignalR trace logs:
WS Connecting to: ws://myapp.cloudapp.net/signalr/connect?clientProtocol=1.4&transport=webSockets&connectionData=[{"Name":"MessageBusHub"}]&connectionToken=...
OnError(System.Net.WebSockets.WebSocketException (0x80004005): An internal WebSocket error occurred. Please see the innerException, if present, for more details. ---> System.Net.Sockets.SocketException (0x80004005): An existing connection was forcibly closed by the remote host
It then proceeds to try again using server sent events and long polling with the same error each time.
I'm using the following endpoint in my Cloud service config:
<Endpoints>
<InputEndpoint name="SignalREndpoint" protocol="http" port="80" localPort="80" />
</Endpoints>
And here is how I create my OWIN web app:
var endpoint = RoleEnvironment.CurrentRoleInstance.InstanceEndpoints["SignalREndpoint"];
string webAppUrl = $"{endpoint.Protocol}://{endpoint.IPEndpoint}";
_webApp = WebApp.Start<Startup>(webAppUrl);
Finally, here's how I configure SignalR:
public class Startup
{
public void Configuration(IAppBuilder app)
{
app.UseCors(CorsOptions.AllowAll);
app.UseServerAuthentication();
GlobalHost.DependencyResolver.UseServiceBus(CloudConfigurationManager.GetSetting("ServiceBusConnectionString"), "SignalRMessageBus");
app.MapSignalR(new HubConfiguration()
{
EnableDetailedErrors = true,
});
}
}
In the client project I am simply using a HubConnection to connect using the following URL for local testing, http://localhost:80, and the following URL for connecting to the cloud instance, http://myapp.cloudapp.net
I'm not sure what's different between the actual Azure instance and my local emulator that's causing it to not work in the cloud.
Interestingly, if I use the browser to connect to the URL http://myapp.cloudapp.net/signalr/hubs, it works and returns the JS proxy file.

Have you tried using TCP instead of HTTP as a protocol?
I am not a SignalR expert in any way, but I know about it. When we host our server (XSockets.NET) on Azure worker roles we configure the protocol to be TCP (not HTTP).
Have no idea why it would work on localhost though.
Another thing to consider is if the worker role supports websockets? SignalR requires IIS8+ for websocket support and I have no idea if you have access to that in a worker role. There are no options in Azure to turn websockets on/off on a worker role (from what I can see). So my guess is that there is no Microsoft WebSockets in the worker role. By I might be wrong here!
EDIT: Looked at one of my instances and saw that I can change OS and that the default one is 2012 Server. So Microsoft websockets should be available!

WCF with visual studio 2012

I am new WCF programming, I did followed series of Getting Started tutorials from following link
http://msdn.microsoft.com/en-us/library/ms734712.aspx
I have hosted service in console application but when I tried to create a client and tried to add service reference I got the following exceptions.
There was an error downloading
'http: localhost:8000/GettingStarted/mex/_vti_bin/ListData.svc/$metadata'.
The request failed with HTTP status 405: Method Not Allowed. Metadata
contains a reference that cannot be resolved:
'http: localhost:8000/GettingStarted/mex'. There was no endpoint
listening at http: localhost:8000/GettingStarted/mex that could
accept the message. This is often caused by an incorrect address or
SOAP action. See InnerException, if present, for more details. The
remote server returned an error: (404) Not Found. If the service is
defined in the current solution, try building the solution and adding
the service reference again.
code of hosting application
class Program
{
static void Main(string[] args)
{
// Step 1 Create a URI to serve as the base address.
Uri baseAddress =
new Uri("http://localhost:8000/GettingStarted/");
// Step 2 Create a ServiceHost instance
ServiceHost selfHost =
new ServiceHost(typeof(CalculatorService), baseAddress);
try
{
// Step 3 Add a service endpoint.
selfHost.AddServiceEndpoint(typeof(ICalculator),
new WSHttpBinding(),
"CalculatorService");
// Step 4 Enable metadata exchange.
var smb = new ServiceMetadataBehavior();
smb.HttpGetEnabled = true;
selfHost.Description.Behaviors.Add(smb);
// Step 5 Start the service.
selfHost.Open();
Console.WriteLine("The service is ready.");
Console.WriteLine("Press <ENTER> to terminate.");
Console.WriteLine();
Console.ReadLine();
// Close the ServiceHostBase to shutdown.
selfHost.Close();
}
catch (CommunicationException ce)
{
Console.WriteLine("exception: {0}", ce.Message);
selfHost.Abort();
}
}
}
Now I am unable to figure out what the problem is. I am using visual studio 2012 and .net platform 4.5.

I had a similar issue as well, messing with this. Yes you seem to have followed the tutorial correctly, but if you want to connect to it and consume as a service (as in make a service reference) you must also add in the MEX service enpoint. Add this line after your selfhost.Description.Behaviors.Add(smb):
selfhost.AddServiceEndpoint(
typeof(IMetadataExchange),
MetadataExchangeBindings.CreateMexHttpBinding(),
"http://localhost:8000/GettingStarted/mex");
That should enable you to connect via "Add Service Reference". Also, I have found depending on your system, you may need to run VS as admin to allow for connection to network (in case you accidentally told it no in the past).

Judging from the error message it seems that there is no service listening at the specified port. You need to have the console application which hosts the service running when you are trying to add a service reference to it.

Apparently, the service is not running which means there is no endpoint listening at the URL you are using to create the service reference.
You can host the service in IIS, or keep the console application running as Damir mentioned above.

Make sure your server is running when you are trying to access it. Also check the configuration on the server and make sure your client's endpoint matches the server's endpoint. Make sure you're using the same binding as well, while you're at it.
Make sure the server is listening and the server's firewall isn't blocking you.
If you made a change to your WCF service don't forget to regenerate the service reference for your client application.

Are you sure you have defined a MEX endpoint? This is what provides metadata information about your service, so that studio can generate a client proxy.
In the tutorial you linked to, it is this bit:
// Step 4 Enable metadata exchange.
ServiceMetadataBehavior smb = new ServiceMetadataBehavior();
smb.HttpGetEnabled = true;
selfHost.Description.Behaviors.Add(smb);

If you are hosting the web service in IIS, check in web.config(under behaviours section)
httpsGetEnabled is set to True

I ran into a similar problem today. However, for me it wasn't needed for me to explicitly add the Endpoints, as #iMortalitySX already said.
I had a different reason for failing: I was binding to http://0.0.0.0, thinking the listen IP doesn't matter. Indeed, via SoapUI I was able to connect and to use the Service. But when trying to discover the service in another Visual Studio project, the discovery would fail, as VS would get the initial response, but then follow up links that contained http://0.0.0.0 and then fail.
So changing http://0.0.0.0 into the correct IP of my machine fixed my problem.

Try put the uri address in Your browser. In my case I was able to see an ExceptionDetail.

WCF error "no endpoint listening" with named pipes

I'm using WCF with .NET 3.5 I am using named pipes but keep getting the error
There was no endpoint listening at
net.pipe://localhost/Test that could
accept the message. This is often
caused by an incorrect address or SOAP
action.
I followed the tutorial http://www.switchonthecode.com/tutorials/wcf-tutorial-basic-interprocess-communication but the problem remains. The endpoints on both the client and server are the same (I checked spelling etc). There is no config file for this project but the config is in the code.
EDIT: Code (client):
ChannelFactory<ITest> pipeFactory =
new ChannelFactory<ITest>(
new NetNamedPipeBinding(),
new EndpointAddress(
"net.pipe://localhost/test"));
ITest test= pipeFactory.CreateChannel();
test.doStuff();
SERVER:
serviceHost = new ServiceHost(typeof(Test), new Uri("net.pipe://localhost"));
serviceHost.AddServiceEndpoint(typeof(ITest), new NetNamedPipeBinding(), "test");
File.Create(#"C:\test.txt");
serviceHost.Open();
Thanks

On the server side don't include base addresses when you create the ServiceHost instance. Instead, provide the fully qualified endpoint address when you add the service endpoint:
serviceHost = new ServiceHost(typeof(Test));
serviceHost.AddServiceEndpoint(typeof(ITest), new NetNamedPipeBinding(), new EndpointAddress("net.pipe://localhost/test"));
File.Create(#"C:\\test.txt");
serviceHost.Open();

This could be:
You are running it as a windows service and the service is not running
You are running it as a console app and there is no console.readline, so it just exists
You are running client and server on two different machines so that localhost is not going to the machine with the service.

Another possibility to fix this root issue if you are getting an error that no net.pipe address can be found at your url (i.e. http://localhost:1234/MyService/etc/) is to make sure that the Net.Pipe Listener Adapter Windows Service is started. (I also started Net.Tcp Listener Adapter)
The service does not seem to be enabled or started in some scenarios especially when deploying out to a remote server that might not of had a lot of the development tools installed that actively use these services. Starting the service fixed the issue.