TACACS+.
TACACS+ (Terminal Access Controller Access-Control System Plus) is an access control protocol for routers, network access servers, and other networked computing devices. TACACS+ provides separate authentication, authorization and accounting services. See Configuring TACACS+.
LDAP and LDAP over SSL.
Oracle ILOM supports LDAP authentication for users, based on the OpenLDAP software. LDAP is a general-purpose directory service. A directory service is a centralized database for distributed applications designed to manage the entries in a directory. Thus, multiple applications can share a single-user database. LDAP over SSL offers enhanced security to LDAP users by way of SSL technology.