Realm not local to KDC while getting initial credentials

We can't get WinRM to work:

Let me please describe all we did:

we followed the steps in how to enable WinRM. We can test that the server from another server one doing this:

"winrm identify -r:<server name>@<domain name>.com -auth:Kerberos -u:<user>@<domain name> -p:<user password>"

we get back:

IdentifyResponse
    ProtocolVersion = http://schemas.dmtf.org/wbem/wsman/1/wsman.xsd
    ProductVendor = Microsoft Corporation
    ProductVersion = OS: 6.1.7601 SP: 1.0 Stack: 2.0

When we model the device from Zenoss we get:

2017-01-14 18:17:15,899 ERROR zen.PythonClient: Error on <servername>.<domain name>.com: kinit: Realm not local to KDC while getting initial credentials

we are using the same user name and password as the one we used to test it from the other server via the command line.

We tried almost every link on the net but we alwasy ended up with the same message.

If we change the <user name> and/or <user password> we get a message of invalid credentials, which makes believe that part is correct. 

We do have Kerberos enable on the server.

Does anybody has an idea of what might be going on?

Our Zenoss is community edition running on CentOS

Regards, Hugo