I'm getting the "There was no endpoint listening at net.pipe://localhost" error as described in other places but I cannot seem to find a real answer.

This is a great identifier of the problem:
<http://kennyw.com/indigo/102>

> 
> When using WCF, Windows authentication
>  is performed through SSPI-Negotiate,
>  which in most cases will select
>  Kerberos as the actual authentication
>  mechanism. However, if the target SPN
>  passed to SSPI is a well formed SPN
>  for the local computer account (e.g.
>  host/[dns machine name]) then
>  Negotiate will use NTLM (loopback
>  optimization) and the access token
>  will not have the Network SID (and
>  therefore will be usable with
>  NetNamedPipes).
> 
> 
> 

But it doesn't tell me how to resolve the issue. I am creating my endpoint programmatically.

```
var binding = new NetNamedPipeBinding();
binding.Security.Mode = NetNamedPipeSecurityMode.Transport;
binding.Security.Transport.ProtectionLevel = ProtectionLevel.EncryptAndSign;

var id = EndpointIdentity.CreateSpnIdentity("host/" + Environment.MachineName);
var endpointAddress = new EndpointAddress(new Uri(serviceClientUrl), id);

var client = new ServiceClient(binding, endpointAddress);

```

I'm guessing that my issue is in the CreateSpnIdentity but I'm not sure what value to use.

**Additional Info:**
To elaborate on this for more context. The Wcf service is hosted as a Windows Service running under the NetworkService account (I've tried Local System). The service is created using the default NetNamedPipeBinding constructor:

```
host.AddServiceEndpoint(typeof(IService), new NetNamedPipeBinding(), "ServiceName");

```

I've created a SharePoint webpart that uses this service. The kicker is that if the SharePoint site is set to forms based authentication or just the machine name is used in the url under Windows Authentication then there are no issues. **ONLY** if the fully qualified machine name is used for the url under Windows authentication do I get the above error.

I'm pretty sure this has to do with the NTLM Kerberos issues descibed in the article but I'm not sure how to get around it.