Kerberos
Even if you have configured multiple LDAP systems, you can use only one LDAP server with Kerberos authentication.
When using multiple LDAP systems, the Ignore realm from service ticket property under Kerberos -> Advanced Settings must be enabled.
SAML
If a user is created during login using SAML, the user name will not have any prefix and is assigned to the default user group. This user is not mapped to any LDAP server.
Single sign-on
If users have the same login ID in different LDAP servers, the Single sign-on login fails. Users must enter their passwords manually instead.