Problem running the WCF 4 DiscoveryProxy sample 08 October 2009 Peter-Himschoot WCF Today I was playing around with managed WS-discovery with WCF 4. To try a couple of things I used the WCF sample DiscoveryProxy. However running the sample gave me this error: {"A TCP error (10013: An attempt was made to access a socket in a way forbidden by its access permissions) occurred while listening on IP Endpoint=0.0.0.0:8001."} The solution is simple: The probing endpoint address was using a socket used by another application. So to make the sample work I changed the port number in the endpoint: Uri probeEndpointAddress = new Uri("net.tcp://localhost:8020/Probe"); That fixed the problem. Don’t forget to update the client as well, because it also uses this endpoint. .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; }