Providing SSO by integrating Linux (or FreeBSD) with a directory service, like Microsoft Active Directory (AD), is no where as daunting as it once was, and highlights some fascinating subsystems that enable users to be defined from a variety of data sources (such as LDAP) other than just the traditional /etc/passwd file. Initial setup Kerberos Create service keytab on AD System Security Services Daemon (sssd) Name Service Switch (nss) PAM (Pluggable Authentication Module) Testing Listing Users Listing Groups id Troubleshooting Samba (smbd) Join Issues Clock Synchronisation Issues Clearing SSSD Cache End to end script (for Ansible) Initial setup Update /etc/resolv.