[Samba] Kerberos and NTLMv2 authentication

[eguigne at pasteur-cayenne.fr]

Dear Samba Users,

I set a samba share (4.8.1) on a linux (centos 7) as server member ;
authentication is done against a AD win 2012 R2 server through winbind.

I thought authentication was using kerberos, but I checked log and found :

Auth: [SMB2,(null)] user [MYDOMAIN]\[mydomainuser] at [mar., 11 juin 2019
10:21:42.000927 -03] with [NTLMv2] status [NT_STATUS_OK] workstation
[CANONDCE0BD]

Below, part of my smb.cnf :

security = ads

realm = MYDOMAIN
workgroup = MYDOMAIN

kerberos method = secrets and keytab

server signing = mandatory

client signing = mandatory

How can I tell samba using kerberos instead of NTLMv2 ? Or is it in
winbind configuration ?

Best Regards,
EdG