protocol. It allows clients to verify the identity of the user, based on
authentication performed by an external authorization server.
+[[user-realms-pam]]
Linux PAM Standard Authentication
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
authentication realm.
+[[user-realms-pve]]
{pve} Authentication Server
~~~~~~~~~~~~~~~~~~~~~~~~~~~
required to set a password for this type of user upon creation.
+[[user-realms-ldap]]
LDAP
~~~~
be carried out automatically with <<pveum_ldap_sync, syncing>>.
+[[user-realms-ad]]
Microsoft Active Directory (AD)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~