You can configure a realm in one of these ways:
In the Administration Console, open the Security component under the relevant configuration and go to the Realms page. For details, see the Sun Java System Application Server Enterprise Edition 8.1 2005Q2 Administration Guide.
Use the asadmin create-auth-realm command to configure realms on local servers. For details, see the Sun Java System Application Server Enterprise Edition 8.1 2005Q2 Reference Manual.