Tim Van Wassenhove

Passionate geek, interested in Technology. Proud father of two

08 Sep 2007

Query a Web Service hosted outside IIS with it's DNS name

Yesterday someone asked the following:

My first attempt was to simulate the problem. I added an entry in my hosts file so that example.com resolves to (My machine’s IP address) and wrote the following code

EndpointReference epr = new EndpointReference(new Uri("soap.tcp://example.com:9090/BookService"));
SoapReceivers.Add(epr, typeof(BookService));

When i tried to run this code i received an ArgumentException: “WSE813: The following transport address could not be mapped to a local network interface: soap.tcp://example.com:9090/BookService”. My intuition said that i should help the infrastructure a little

EndpointReference epr = new EndpointReference(new Uri("soap.tcp://"));

The application started fine this time, but when i used wsewsdl3.exe to generate the proxy i received the following error: Destination Unreachable. Anyway, after a lot of experimenting i found that the following method allows me to generate a proxy using the DNS name

static EndpointReference GetEndpointReference(string host, int port, string path)
	// we happy:
	// for the Address part we use the DNS name
	// infrastructure happy:
	// for the Via par we use the first IP that maps to the provided DNS name

	Uri address = new Uri(string.Format("soap.tcp://{0}:{1}/{2}", host, port, path));
	Uri via = new Uri(string.Format("soap.tcp://{0}:{1}/{2}", Dns.GetHostEntry(host).AddressList[0], port, path));
	return new EndpointReference(address, via);

static void Main(string[] args)
	EndpointReference epr = GetEndpointReference("example.com", 9090, "BookService");
	SoapReceivers.Add(epr, typeof(BookService));

	Console.Write("{0}Press any key to continue...", Environment.NewLine);


As always, you can download a sample solution with a windows service that hosts the webservice, and a console application that consumes the webservice: MsdnSoapExample.zip