Fully Qualified Domain Name (FQDN) mapping enables the Authentication Service to take corrective action in the case where a user may have typed in an incorrect URL. This is necessary, for example, when a user specifies a partial host name or IP address to access protected resources. This feature can also be used to allow access to one instance of OpenSSO Enterprise using many different aliases. For example, you might configure one instance of OpenSSO Enterprise as intranet.example.com for employees and extranet.example.com for partners. For more information, see Mapping Fully Qualified Domain Names in Sun OpenSSO Enterprise 8.0 Administration Guide.