WCF Identity NTLM Kerberos

Question

I have read numerous posts and articles about the element in client endpoints on a WCF client but I am still a little confused. I have a client which gets SSPI errors when attempting to communicate with a net tcp WCF service. However, when I add the following into the configuration it works fine

<identity>
   <servicePrincipalName />
</identity>

Now from what I have read this is telling the service to use NTLM rather than Kerberos. However, I am still not getting it.

Does anyone have a few moments to explain this simply for me please. So, what is going on here, a little bit of background on the difference of NTLM and Kerberos, why it would work with one and not the other, why this element doesn't need a value, how to configure a service not to need it and why it is needed at all?

Thanks

Answer 1

Here is a blog post explaining ntlm versus kerberos with respect to WCF:

http://blogs.msdn.com/ashishme/archive/2006/11/10/ntlm-vs-kerberos-windows-communication-foundation.aspx