I am trying to find out why there is no Kerberos authentication on my SQL instance :

SELECT COUNT (auth_scheme) as nb, auth_scheme --net_transport, client_net_address 
FROM sys.dm_exec_connections
GROUP BY auth_scheme

nb auth_scheme

2 (Unknown)

151 NTLM


Using KerberosConfigurationManager, requiered SPNs seems to be correctly and automatically registered:

enter image description here

Here's the error log regarding the SPN for the instance :

enter image description here

Could you provide ideas to investigate why there is no Kerberos authentication?

All the conditions list at this Microsoft Docs page have been met.


Cannot add the output because this is confidential info, but the instance is correctly registered :


  • Are the clients connecting from a remote host using host name that matches the SPN? May 3, 2018 at 15:59
  • Unfortunatelly I have no idea David, I am only working on the database side. maybe i could put in place a profiler trace in order to get more details ?
    – Mickael
    May 4, 2018 at 7:30


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